Дисертації з теми "Light interference"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Light interference.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Light interference".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Shah, Samit Friedman Simon H. "Light activated RNA interference." Diss., UMK access, 2007.
Знайти повний текст джерелаАнотація:
Thesis (Ph. D.)--School of Pharmacy and Dept. of Chemistry. University of Missouri--Kansas City, 2007."A dissertation in pharmaceutical science and chemistry." Advisor: Simon H. Friedman. Typescript. Vita. Description based on contents viewed July 16, 2008; title from "catalog record" of the print edition. Includes bibliographical references (leaves 206-220). Online version of the print edition.
2
Kim, Hyunsu. "Interference lithography with extreme ultraviolet light." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/410353/.
Повний текст джерелаАнотація:
In photolithography, increasing pattern density is a key issue for development of semiconductor devices. Extreme ultraviolet (EUV) radiation is the next generation light source for overcoming the resolution limit of conventional photolithography in order to obtain nanostructures of higher density. In this thesis, we focus on investigating resolution limits of interference patterns produced by EUV radiation. Optical properties of interference fringes obtained using different types of compact EUV sources are studied with regard to increasing pattern density. Rigorous simulations of optical wave propagation of EUV radiation are performed to investigate the resolution limits of interference fringes for the fractional Talbot effect, the achromatic Talbot effect, and an image of Talbot carpet that has an optical property of ever-decreasing size of interference fringes. In experiments, interference lithography has been performed with three different types of compact EUV sources including a gas discharge produced plasma, a plasma based EUV laser, and a high-harmonic generation source. We analyze optical characteristics of particular EUV sources resulting in different capabilities of patterning. Also different optical system designs capable of overcoming the limitations of optical properties of EUV radiation are investigated. We expect that the study of EUV interference lithography can be helpful for understanding the upcoming photolithography resolution and also can be useful as a technology for fabricating very fine structures.
3
Wilson, Rebecca Anne. "The electron-beam tunable interference filter spatial light modulator." Thesis, Heriot-Watt University, 1992. http://hdl.handle.net/10399/1494.
Повний текст джерела
4
Chen, Zhe. "Interference mitigation techniques for optical attocell networks." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/22868.
Повний текст джерелаАнотація:
The amount of wireless data traffic has been increasing exponentially. This results in the shortage of radio frequency (RF) spectrum. In order to alleviate the looming spectrum crisis, visible light communication (VLC) has emerged as a supplement to RF techniques. VLC uses light emitting diodes (LEDs) for transmission and employs photodiodes (PDs) for detection. With the advancement of the LED technology, LEDs can now fulfil two functions at the same time: illumination and high-speed wireless communication. In a typical indoor scenario, each single light fixture can act as an access point (AP), and multiple light fixtures in a room can form a cellular wireless network. We refer to this type of networks as ‘optical attocell network’. This thesis focuses on interference mitigation in optical attocell networks. Firstly, the downlink inter-cell interference (ICI) model in optical attocell networks is investigated. The conventional ray-tracing channel model for non-line-of-sight (NLOS) path is studied. Although this model is accurate, it leads to time-consuming computer simulations. In order to reduce the computational complexity, a simplified channel model is proposed to accurately characterise NLOS ICI in optical attocell networks. Using the simplified model, the received signal-to-interference-plus-noise ratio (SINR) distribution in optical attocell networks can be derived in closed-form. This signifies that no Monte Carlo simulation is required to evaluate the user performance in optical attocell networks. Then, with the knowledge of simplified channel model, interference mitigation techniques using angle diversity receivers (ADRs) are investigated in optical attocell networks. An ADR typically consists of multiple PDs with different orientations. By using proper signal combining schemes, ICI in optical attocell networks can be significantly mitigated. Also, a novel double-source cell configuration is proposed. This configuration can further mitigate ICI in optical attocell networks in conjunction with ADRs. Moreover, an analytical framework is proposed to evaluate the user performance in optical attocell networks with ADRs. Finally, optical space division multiple access (SDMA) using angle diversity transmitters is proposed and investigated in optical attocell networks. Optical SDMA can exploit the available bandwidth resource in spatial dimension and mitigate ICI in optical attocell networks. Compared with optical time division multiple access (TDMA), optical SDMA can significantly improve the throughput of optical attocell networks. This improvement scales with the number of LED elements on each angle diversity transmitter. In addition, the upper bound and the lower bound of optical SDMA performance are derived analytically. These bounds can precisely evaluate the performance of optical SDMA systems. Furthermore, optical SDMA is shown to be robust against user position errors, and this makes optical SDMA suitable for practical implementations.
5
Bhattarai, Khagendra Prasad. "Interference of Light in Multilayer Metasurfaces: Perfect Absorber and Antireflection Coating." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6680.
Повний текст джерелаАнотація:
We have studied several metamaterials structures with multiple layers by explaining them theoretically and verifying experimentally. The engineered structures we have designed work either as a perfect absorber or antireflection coating. The multilayer model as we call it Three Layer Model (TLM) has been developed, which gives the total reflection and transmission as a function of reflection and transmission of individual layers. By manipulating the amplitude and phase of the reflection and the transmission of the individual layers, we can get the required functionality of the optoelectronic devices. To get zero reflection in the both perfect absorber and the antireflection coating, the amplitude and phase conditions should be satisfied simultaneously. We have employed the numerical simulation of the structures to verify those conditions for all of the work presented here. As the theoretical retrieval method to extract the effective permittivity and effective permeability of the metamaterial contains air on the both side of the structure, we have dielectric at least on one side practically, that gives a little bit deviated result. We have modified the retrieval method to better fit with the multilayer structure by introducing air on the both side of the resonator using transfer matrix method and use it throughout all the works.
We have explained the perfect absorption of the EM wave through Fabry-Perot cavity bounded by the resonator mirror and the metallic film. The metallic film acts as the close boundary whereas the resonator acts as the quasi-open boundary with very high effective permittivity, which leads to the characteristic feature of subwavelength thickness. We have shown numerically that the ultra-thin thickness makes the perfect absorber angular independent. We have also explained the phenomenon of perfect absorption through Impedance Matched Theory and Transmission Line Theory, and showed their matching with TLM. We have also developed the Meta Film Model by considering the resonator as a homogeneous thin film characterized by the effective permittivity and permeability giving rise to the same behavior as the original multilayer structure. We have shown that the resonance of the metamaterial resonator is very far from the resonance of the absorber, it behaves as the medium of high refractive index and very low loss. We have also shown that the density of states of the absorber is increased as compared to the resonator itself. We have investigated that the resonance peaks of the absorber arise from the combination of Fabry- Perot cavity modes and surface plasmon resonance modes. All the modes with increased spacer thickness are assigned with specific names describing the mode profiles. We have shown the application of perfect absorber as a refractive index sensor. It is used as a plasmonic sensor to detect the refractive index change of the chemical and biological samples. To increase the sensitivity, we have etched the dielectric spacer below the resonator, where electric field is localized and enhanced. We have found that the sensitivity (wavelength shift per refractive index change) and the Figure of Merit (FOM*) as an indicator of performance of the device both are enhanced significantly.
We have employed metamaterial (MM) anti-reflection (AR) coating to avoid the shortcomings of the conventional thin film coating in three different cases of the structures. At first, we have deployed metamaterial Metal Disk Array (MDA) on the top of conventional coating material (BCB) with homogeneous substrate to enhance the transmission of EM wave. Then conventional AR coating is employed to the dispersive media (metal Hole Array) to enhance the transmission. We have shown that Impedance matched condition has been satisfied not only for homogeneous media, but for dispersive media also. At the end, we have employed the MM AR coating to the MM dispersive media (MHA). The two MM layers may interact with each other and may degrade the SPP wave of the MHA, which is essential to enhance the performance of the devices. To investigate the effect of interaction, we perform the simulation of the MDA, which shows that the resonance of the MDA is far from the antireflection resonance and hence the electric field of the SPP is significantly increased (~30%). With an improved retrieval method, the metasurface is proved to exhibit a high effective permittivity (εeff~30) and extremely low loss (tanδ~0.005). For all of the three AR structures, a classical thin film AR coating mechanism is identified through analytical derivations and numerical simulations. The properly designed εeff and μeff of the meta surface lead to the required phase and amplitude conditions for the AR coating, thereby paving the way for the improved performance of the optoelectronic devices.
We have used MHA as a dispersive media to get extraordinary optical transmission (EOT). To understand the behavior of the SPP peaks, we have investigated the shifting and splitting of the spoof SPP resonance by varying the polar angle and azimuthal angle. The amplitude of extraordinary optical transmission also shows angle dependence and exhibits mirror-image or translational symmetries. Our measurements and simulations of the THz spoof SPP waves match very well with the theoretical predictions. The angle dependence results provide the important information for designing THz plasmonic devices in sensor and detector applications.
6
Noorizadeh, Sahand. "SLM-based Fourier Differential Interference Contrast Microscopy." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2011.
Повний текст джерелаАнотація:
Optical phase microscopy provides a view of objects that have minimal to no effect on the detected intensity of light that are unobservable by standard microscopy techniques. Since its inception just over 60 years ago that gave us a vision to an unseen world and earned Frits Zernike the Nobel prize in physics in 1953, phase microscopy has evolved to find various applications in biological cell imaging, crystallography, semiconductor failure analysis, and more. Two common and commercially available techniques are phase contrast and differential interference contrast (DIC). In phase contrast method, a large portion of the unscattered light that accounts for the majority of the light passing unaffected through a transparent medium is blocked to allow the scattered light due to the object to be observed with higher contrast. DIC is a self-referenced interferometer that transduces phase variation to intensity variation. While being established as fundamental tools in many scientific and engineering disciplines, the traditional implementation of these techniques lacks the ability to provide the means for quantitative and repeatable measurement without an extensive and cumbersome calibration. The rapidly growing fields in modern biology meteorology and nano-technology have emphasized the demand for a more robust and convenient quantitative phase microscopy. The recent emergence of modern optical devices such as high resolution programmable spatial light modulators (SLM) has enabled a multitude of research activities over the past decade to reinvent phase microscopy in unconventional ways. This work is concerned with an implementation of a DIC microscope containing a 4-f system at its core with a programmable SLM placed at the frequency plane of the imaging system that allows for employing Fourier pair transforms for wavefront manipulation. This configuration of microscope provides a convenient way to perform both wavefront shearing with quantifiable arbitrary shear amount and direction as well as phase stepping interferometry by programming the SLM with a series of numerically generated patterns and digitally capturing interferograms for each step which are then used to calculate the objects phase gradient map. Wavefront shearing is performed by generating a pattern for the SLM where two phase ramp patterns with opposite slopes are interleaved through a random selection process with uniform distribution in order to mimic the simultaneous presence of the ramps on the same plane. The theoretical treatment accompanied by simulations and experimental results and discussion are presented in this work.
7
Allan, James Donald Campbell. "An application of optical interference to dynamic position measurement in three dimensions." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/6627.
Повний текст джерелаАнотація:
This thesis is concerned with the measurement of the positions of points and bodies moving in trajectories in three dimensions, and the use of a new technique of optical interference which allows such measurements to be made dynamically. A variety of existing techniques for both static and dynamic three-dimensional position measurement are discussed, and the design of the new interferometer is introduced. The geometry of points, curves and surfaces in three dimensions is examined, with emphasis on the intersection of the point loci represented by the coordinate output of measuring instruments. The coordinates output by the interferometer represent surface loci which are quadric surfaces. A method of calculating the position and orientation of a body using three quadric surface intersection curves is presented. Diffraction of monochromatic light at an aperture is considered and it is shown that an interferometer working by division of wavefront can be used to obtain continuous information about the movement of the source of radiation, with that source free to move in up to three dimensions. A lens may be used to produce a compact instrument based on these principles. The diffraction integral equations are modified to incorporate the effect of a lens in the diffraction field. It is shown that even complex lenses can be represented by a few parameters in the diffraction equations. From the evaluation of these diffraction integrals, it is shown how the movement of interference fringes provides a coordinate output and how this is related to the locus of the radiation source. A method of obtaining very high resolution measurements of interference fringe pattern movement is presented. The interferometer was built and tested and the above theory verified in practice in a series of optical bench tests. The implementation of a system which uses this interferometer to measure the dynamic performance of industrial robots is considered. The optimum positions for the instruments are derived, and the method of designing the interferometer to give the required resolution is presented.
8
Shankaranarayanan, N. K. "Mode-mode interference in optical fibers: analysis and experiment." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45891.
Повний текст джерелаАнотація:
Interference between the modes of an optical fiber generates specific mode (intensity) patterns which get modulated by disturbances in the optical fiber system. Mode-mode interference has been analyzed from first principles and a model based on differential phase modulation presented. Mode-mode interference effects such as intensity modulation of the mode patterns are directly related to differential phase modulation between modes which arises due to the difference between the propagation constants of the constituent modes. Practical implementation of modal methods involves selective launching of modes and processing of the output pattern to demodulate the information.
Axial strain has been chosen as the modulating mechanism in experiments designed to quantify mode-mode interference effects. Quasi-statically varying strain as well as vibrational strain was used to study 'dc' and 'ac' mechanisms. Specific mode combinations have been excited and their radiation patterns identified. Mode pattern changes have been described. Experimental observations and results correlate very well with analysis.
Master of Science
9
NAHM, KIEBONG. "LIGHT SCATTERING BY POLYSTYRENE SPHERES ON A CONDUCTING PLANE (MIE, IMAGE CHARGE, INTERFERENCE, BRDF)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188071.
Повний текст джерелаАнотація:
A system consisting of a sphere sitting on a clean mirror was modeled as a two particle system: the real sphere and its image sphere, treating the mirror as a conducting plane. When the system was irradiated with a plane-polarized collimated laser beam with varying angles of incidence, the scattering from each particle was assumed to follow Mie's solution for light scattering by a sphere. Phase difference between the scattering by the real sphere and the one by its image sphere was assessed by the geometry of the model. The far field solutions from each of the spheres were added to yield a phase dependent intensity function. Another model assumed no phase correlation between the two and the intensities from each spheres were added. Also discussed is the Double Interaction Mode, which takes the mirror-sphere separation into consideration. These theoretical results were converted to Bidirectional Reflectance Distribution Functions (BRDF). The theoretical as well as the empirical surface scattering from a good quality optical surface was introduced. The BRDF values thus calculated were added to the background scattering by the mirror since no interaction was assumed between the spheres and the rough metallic surface of the mirror. The test sample was prepared with polystyrene spheres with the nominal diameter of 0.984 μm on a high quality aluminum mirror. The BRDF data from this sample with 6328Å and 4416Å were compared with the one obtained with the model described above. The comparison strongly indicated that there existed no phase correlation between the scatterings by the two spheres. Determination of the sphere size and practical applicability for estimating the sphere number density on the surface are also discussed.
10
Kim, Yang-Hyo. "High resolution imaging and lithography using interference of light and surface plasmon waves." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42303.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaf 28).
The resolution of optical imaging and lithography is limited by the wave nature of light. Studies have been undertaken to overcome the diffraction limit for imaging and lithography. In our lab, the standing wave surface plasmon resonance fluorescence (SW-SPRF) microscopy was developed. It is a combination of standing wave total internal reflection fluorescence (SW-TIRF), one of structured illumination techniques, with surface plasmon resonance (SPR). The SW-TIRF approach decreases the excitation wavelength by interfering two coherent light rays on the substrate and producing an evanescent standing wave field between the object and a high refractive index substrate. Evanescent standing wave illumination generates a sinusoidal interference pattern with 2n times higher-spatial frequency than original light, where n is the refractive index of the substrate allowing higher lateral resolution. Surface plasmon is generated by reflecting a light on the gold surface through the cover glass at a specific angle inducing collective excitation of electrons in the metal. The SPR contributes a better signal-to-noise ratio by inducing an enhanced evanescent electric field to excite fluorophores. With the SW-TIRF instrument, about 100 nm resolution was obtained. In this thesis, we aim to produce less than 50 nm resolution lithography and imaging using corrugated gold surface. The induction of surface plasmon wave with large wave number is made possible by the sinusoidal gold surface allowing wave number matching between the excitation light and the surface plasmon wave. This wave number matching requires proper optimization of parameters like grating constant, perturbation depth, incidence angle of the beam, and excitation wavelength. The fabrication of the corrugated gold surface would be done by e-beam etching with varying parameters.
(cont.) For lithography, nano-patterns would be investigated on azo dye thin films, Congo-Red dye with spin-coating, exposed by an interference of evanescent waves propagating on a substrate. The result patterns would be measured with AFM. For imaging, sub-diffraction limited fluorescent particle would be used for point spread function measurement and high-resolution demonstration.
by Yang-Hyo Kim.
S.M.
11
Gopalan, Kavitha. "The effects of continuous wave interference on Global Positioning System software radio processing." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1173895104.
Повний текст джерела
12
Kim, Hyun-Su Verfasser], Larissa [Akademischer Betreuer] [Juschkin, and Thomas Günter [Akademischer Betreuer] Taubner. "Interference lithography with extreme ultraviolet light / Hyun-Su Kim ; Larissa Juschkin, Thomas Günter Taubner." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1162498153/34.
Повний текст джерела
13
Kim, Hyun-Su [Verfasser], Larissa [Akademischer Betreuer] Juschkin, and Thomas Günter [Akademischer Betreuer] Taubner. "Interference lithography with extreme ultraviolet light / Hyun-Su Kim ; Larissa Juschkin, Thomas Günter Taubner." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1162498153/34.
Повний текст джерела
14
Li, Qiaowu. "Examining the effectiveness of interactivity in a 3-dimensional web-based tutorial on interference phenomenon." Master's thesis, Mississippi State : Mississippi State University, 2002. http://library.msstate.edu/etd/show.asp?etd=etd-04092002-141428.
Повний текст джерела
15
Lutkenhaus, Jeffrey Ryan. "Local Phase Manipulation for Multi-Beam Interference Lithography for the Fabrication of Two and Three Dimensional Photonic Crystal Templates." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc955084/.
Повний текст джерелаАнотація:
In this work, we study the use of a spatial light modulator (SLM) for local manipulation of phase in interfering laser beams to fabricate photonic crystal templates with embedded, engineered defects. A SLM displaying geometric phase patterns was used as a digitally programmable phase mask to fabricate 4-fold and 6-fold symmetric photonic crystal templates. Through pixel-by-pixel phase engineering, digital control of the phases of one or more of the interfering beams was demonstrated, thus allowing change in the interference pattern. The phases of the generated beams were programmed at specific locations, resulting in defect structures in the fabricated photonic lattices such as missing lattice line defects, and single-motif lattice defects in dual-motif lattice background. The diffraction efficiency from the phase pattern was used to locally modify the filling fraction in holographically fabricated structures, resulting in defects with a different fill fraction than the bulk lattice. Through two steps of phase engineering, a spatially variant lattice defect with a 90° bend in a periodic bulk lattice was fabricated. Finally, by reducing the relative phase shift of the defect line and utilizing the different diffraction efficiency between the defect line and the background phase pattern, desired and functional defect lattices can be registered into the background lattice through direct imaging of the designed phase patterns.
16
WEST, KAREN FRANCES. "AN EXTENSION TO THE ANALYSIS OF THE SHIFT-AND-ADD METHOD: THEORY AND SIMULATION (SPECKLE, ATMOSPHERIC TURBULENCE, IMAGE RESTORATION)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188021.
Повний текст джерелаАнотація:
The turbulent atmosphere degrades images of objects viewed through it by introducing random amplitude and phase errors into the optical wavefront. Various methods have been devised to obtain true images of such objects, including the shift-and-add method, which is examined in detail in this work. It is shown theoretically that shift-and-add processing may preserve diffraction-limited information in the resulting image, both in the point source and extended object cases, and the probability of ghost peaks in the case of an object consisting of two point sources is discussed. Also, a convergence rate for the shift-and-add algorithm is established and simulation results are presented. The combination of shift-and-add processing and Wiener filtering is shown to provide excellent image restorations.
17
Mathieson, Genevieve. "Thomas Young, Quaker Scientist." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1196288181.
Повний текст джерела
18
Aydogdu, Selcuk. "Near Infrared Interference Filter Design And The Production Withion-assisted Deposition Techniques." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614092/index.pdf.
Повний текст джерелаАнотація:
Near infrared region (NIR) of the electromagnetic spectrum (EM) is defined as 700nm to
1400nm wavelength interval by International Commission on Illumination(CIE). This wavelength
interval is extensively used for target acquisition, night vision, wireless communication
etc. Therefore, filtering the desired portion of EM spectra becomes a need for that kind
of applications. Interference filters are multilayer optical devices which can be designed and
produced for the desired wavelength intervals. The production of near infrared interference
filters is a process of depositing thin material layers on the suitable substrates. In this thesis, a
multilayer NIR filter will be designed for a selected wavelength interval by the use of dierent
materials. Then, transmission quality, thermal stability, dependence of the transmission
values on the incoming beam angle, performance and durability of the filter will be studied.
19
Dyck, Tobias [Verfasser], Uwe [Akademischer Betreuer] Rau, and Andres Fabian [Akademischer Betreuer] Lasagni. "Light trapping by light treatment : direct laser interference patterning for the texturing of front contacts in thin-film silicon solar cells / Tobias Dyck ; Uwe Rau, Andres Fabian Lasagni." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://nbn-resolving.de/urn:nbn:de:101:1-2018071608004058241947.
Повний текст джерела
20
Dyck, Tobias Verfasser], Uwe [Akademischer Betreuer] [Rau, and Andres Fabian [Akademischer Betreuer] Lasagni. "Light trapping by light treatment : direct laser interference patterning for the texturing of front contacts in thin-film silicon solar cells / Tobias Dyck ; Uwe Rau, Andres Fabian Lasagni." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1162845805/34.
Повний текст джерела
21
Ševčík, Michal. "Nanometrologická vibrometrie." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220217.
Повний текст джерелаАнотація:
This thesis deals with the precise measurement of distances in nanometer range at ultrasonic frequencies for the purposes of vibrometry. The paper is primary focused on~nanometric displacement measurement methods. First the thesis deals with the physical phenomena based on light in the theoretical section. This includes interference of light, index of refraction, polarization, interferometry and more. Understanding of these physical laws is crucial for design and assembling of the interferometer. Subjects of interferometric method for precise and fast measurement of the nanometric displacement and vibration are discussed. Interferometer components such as lasers, photodetectors and optical elements are described are described in the final part of this section. Practical section of thesis can be divided into two parts. The design and assembling issues are discussed in the first section. Many problems which I had to solve are described. Control software and implementation of the signal processing is the subject of the second part. I met with particular problems such as phase unwrapping. I solved this problem of discontinuous phase field with user written algorithm. Finally the graphical user interface was created. Using assembled interferometer and written software application I measured vibration of Langevin transducer on ultrasonic frequencies.
22
Klempner, Adam R. "Development of a modular interferometric microscopy system for characterization of MEMS." Link to electronic thesis, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-010407-173332/.
Повний текст джерелаАнотація:
Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: vacuum; shape and deformation measurement; MEMS; vibrometry; scanning white light; Interferometry; thermal; vibration. Includes bibliographical references (136-139 leaves ).
23
Bita, Ion. "Breaking symmetries in ordered materials : spin polarized light transport in magnetized noncentrosymmetric 1D photonic crystals, and photonic gaps and fabrication of quasiperiodic structured materials from interference lithography." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36205.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2006."February 2006."
Includes bibliographical references.
Effects of breaking various symmetries on optical properties in ordered materials have been studied. Photonic crystals lacking space-inversion and time-reversal symmetries were shown to display nonreciprocal dispersion relations, and to exhibit a remarkable set of symmetry-related properties. Even in 1D, these materials are found to display indirect photonic band gaps, backward wave propagating modes (antiparallel phase and group velocities) which enable negative refraction at the air-crystal interface, ability to allow bending light with perpendicular magnetic fields, unidirectional superprism effects, etc. By calculating the complex photonic band structure, we show that the gap modes differ fundamentally from the commonly assumed evanescent modes with purely imaginary wave vectors - solely due to symmetry, we show that the gaps of nonreciprocal photonic crystals have complex wave vectors with both imaginary components and non-zero, frequency dependent real components. This basic finding is further studied in the context of tunneling dynamics, by considering the problem of tunneling time for nonreciprocal photonic band gap barriers (the tunneling wave packet has an energy in the middle of the gap).
(cont.) It was found that the classical Hartman effect (independence of tunneling time on barrier length, beyond a certain length), previously implied as universal, is forbidden solely due to symmetry. Instead of a classical zero group delay, we find that tunneling wave packets with opposite spins display non-zero group delays, with opposite signs. Due to analogies based on symmetry, these results directly impact the problem of spin-polarized electronic tunneling in magnetized noncentrosymmetric semiconductors, such as GaMnAs or carbon nanotubes with applied axial magnetic fields. An interference lithography based fabrication process was developed to produce 2D and 3D quasiperiodically structured materials, which have long-range order but break translational symmetry. Multiple exposure interference lithography was used to fabricate 2D quasicrystals with feature sizes as small as 100nm. Replica molding was used to fabricate transparent and conformable 2D quasiperiodic phase masks, which subsequently allowed the fabrication of 3D structured materials with quasiperiodicity by coherent diffraction lithography. The effect of the higher point group symmetries of 2D quasicrystals on photonic band gap formation (TM polarized only) was studied by finite difference time domain calculations, and it was found that increasing the rotational symmetry does not always lead to wider gaps.
by Ion Bita.
Ph.D.
24
Yin, Liang. "Design and performance analysis of optical attocell networks." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31390.
Повний текст джерелаАнотація:
The exponentially increasing demand for high-speed wireless communications will no longer be satisfied by the traditional radio frequency (RF) in the near future due to its limited spectrum and overutilization. To resolve this imminent issue, industrial and research communities have been looking into alternative technologies for communication. Among them, visible light communication (VLC) has attracted much attention because it utilizes the unlicensed, free and safe spectrum, whose bandwidth is thousand times larger than the entire RF spectrum. Moreover, VLC can be integrated into existing lighting systems to offer a dual-purpose, cost-effective and energy-efficient solution for next-generation small-cell networks (SCNs), giving birth to the concept of optical attocell networks. Most relevant works in the literature rely on system simulations to quantify the performance of attocell networks, which suffer from high computational complexity and provide limited insights about the network. Mathematical tools, on the other hand, are more tractable and scalable and are shown to closely approximate practical systems. The presented work utilizes stochastic geometry for downlink evaluation of optical attocell networks, where the co-channel interference (CCI) surpasses noise and becomes the limiting factor of the link throughput. By studying the moment generating function (MGF) of the aggregate interference, a theoretical framework for modeling the distribution of signal-to-interference-plus-noise ratio (SINR) is presented, which allows important performance metrics such as the coverage probability and link throughput to be derived. Depending on the source of interference, CCI can be classified into two categories: inter-cell interference (ICI) and intra-cell interference. In this work, both types of interference are characterized, based on which effective interference mitigation techniques such as the coordinated multipoint (CoMP), power-domain multiplexing and successive interference cancellation (SIC) are devised. The proposed mathematical framework is applicable to attocell networks with and without such interference mitigation techniques. Compared to RF networks, optical attocell networks are inherently more secure in the physical layer because visible light does not penetrate through opaque walls. This work analytically quantifies the physical-layer security of attocell networks from an information-theoretic point of view. Secrecy enhancement techniques such as AP cooperation and eavesdropper-free protected zones are also discussed. It is shown that compared to AP cooperation, implementing secrecy protected zones is more effective and it can contribute significantly to the network security.
25
Rudhall, Andrew Peter. "Ultrashort laser pulse shaping for novel light fields and experimental biophysics." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3682.
Повний текст джерелаАнотація:
Broadband spectral content is required to support ultrashort pulses. However this broadband content is subject to dispersion and hence the pulse duration of corresponding ultrashort pulses may be stretched accordingly. I used a commercially-available adaptive ultrashort pulse shaper featuring multiphoton intrapulse interference phase scan technology to characterise and compensate for the dispersion of the optical system in situ and conducted experimental and theoretical studies in various inter-linked topics relating to the light-matter interaction. Firstly, I examined the role of broadband ultrashort pulses in novel light-matter interacting systems involving optically co-trapped particle systems in which inter-particle light scattering occurs between optically-bound particles. Secondly, I delivered dispersion-compensated broadband ultrashort pulses in a dispersive microscope system to investigate the role of pulse duration in a biological light-matter interaction involving laser-induced cell membrane permeabilisation through linear and nonlinear optical absorption. Finally, I examined some of the propagation characteristics of broadband ultrashort pulse propagation using a computer-controlled spatial light modulator. The propagation characteristics of ultrashort pulses is of paramount importance for defining the light-matter interaction in systems. The ability to control ultrashort pulse propagation by using adaptive dispersion compensation enables chirp-free ultrashort pulses to be used in experiments requiring the shortest possible pulses for a specified spectral bandwidth. Ultrashort pulsed beams may be configured to provide high peak intensities over long propagation lengths, for example, using novel beam shapes such as Bessel-type beams, which has applications in biological light-matter interactions including phototransfection based on laser-induced cell membrane permeabilisation. The need for precise positioning of the beam focus on the cell membrane becomes less strenuous by virtue of the spatial properties of the Bessel beam. Dispersion compensation can be used to control the temporal properties of ultrashort pulses thus permitting, for example, a high peak intensity to be maintained along the length of a Bessel beam, thereby reducing the pulse energy required to permeabilise the cell membrane and potentially reduce damage therein.
26
Smith, Michael Hughes. "The design of multifunctional hydrogel nanoparticles for drug delivery." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43609.
Повний текст джерелаАнотація:
Hydrogel micro- and nanoparticles (microgels and nanogels) are a promising class of drug delivery vehicles. Composed of hydrophilic polymers arranged into a cross-linked network structure, nanogels show several attractive features for the delivery of macromolecule therapeutics. For instance, the hydrated, porous internal cavity of the nanogel may serve as a high capacity compartment for loading macromolecules, whereas the periphery of the nanogel may be used as a scaffold for conjugating cell-specific targeting moieties. This dissertation presents recent investigations of nanogels as targeted delivery vehicles for oligonucleotides to cancer cells, while exploring new nanogel chemistries that enable future in vivo applications. For instance, synthetic efforts have produced particles capable of erosion into low molar mass constituents, providing a possible mechanism of particle clearance after repeated administration in vivo. In another example, the microgel network chemistry was tuned to promote the encapsulation of charged proteins. In parallel with those synthetic efforts, new light scattering methodologies were developed to accurately quantify the particle behaviors (e.g. loading, erosion). Using multiangle light scattering (MALS), changes in particle molar mass and radius were measured, providing a quantitative and direct approach for monitoring nanogel erosion and macromolecule encapsulation. The new particle chemistries demonstrated, together with enabling light scattering methods, will catalyze the development of improved delivery vehicles in the near future.
27
Kozyreff, Gregory. "Nonlinear aspects of the dynamics induced by dissipative light-matter interaction." Doctoral thesis, Universite Libre de Bruxelles, 2001. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211644.
Повний текст джерелаАнотація:
Dans cette thèse, nous avons appliqué les outils modernes de la théorie des systèmes dynamiques à l'étude des lasers. Le but de ce travail était de mieux comprendre les sources cohérentes existantes en vue de les améliorer et de proposer de nouveaux mécanismes d'amplification lumineuse.Motivé par de récentes expériences menées sur des lasers miniatures avec absorbant saturable, nous en avons repris la description théorique. Les nouvelles valeurs de paramètres suggérées par l'expérience nous ont amenés à découvrir de nouveaux comportements dynamiques pour ces systèmes. En particulier, nous avons décrit comment l'intensité délivrée par ces lasers devenait temporellement sinusoïdale, puis impulsionnelle sur un très petit intervalle de paramètres.
Par la connaissance acquise du laser à absorbant saturable, nous avons pu comprendre comment s'établissait un régime impulsionnel semblable dans un autre laser. Il s'agissait du laser multimode à pompage longitudinalement inhomogène. Il est apparu en effet qu'une partie du milieu emprisonné dans la cavité optique agissait à la manière d'un absorbant saturable, déstabilisant ainsi l'émission continue de ce laser. Nous avons également montré que, dans certaines circonstances, son état dynamique présentait des effets de mémoire. Une autre propriété importante de la dynamique du laser multimode a été mise en évidence: pour de petites perturbations, l'intensité totale présente un comportement plus régulier que les intensités modales prises séparément.
Ce type intrigant d'auto organisation fut rencontré plus tard, lorsque nous avons envisagé la dynamique d'un réseau de lasers à semi conducteur couplés par un feedback optique. Le retard accumulé par la lumière au cours de ce feedback est un paramètre essentiel du problème. Ce système important sur le plan technologique s'est révélé extrêmement riche sur le plan dynamique. Nous avons pu montrer que plus le retard était grand, plus les lasers avaient tendance à se synchroniser. Cela fut observé aussi bien en régime continu qu'en régime périodique ou chaotique. Par une telle synchronisation, la qualité du rayon optique émis par le réseau de lasers augmente spectaculairement, élargissant par là ses possibilités d'application.
Au début des années 1990, les physiciens commencèrent à étudier systématiquement les effets d'interférence quantique dans l'interaction lumière matière. Ceci faisait suite à l'annonce fracassante que de tels effets devaient permettre de construire des lasers sans inversion de population. Récemment, une série d'expériences a montré que de telles interférences quantiques étaient à l’œuvre dans le laser miniature LNP. Une partie de cette thèse y fut consacrée. Nous avons montré que le comportement dynamique observé résultait d'un renforcement quantique de l'absorption stimulée par les niveaux énergétiques inférieurs.
Nous avons poursuivi notre étude des effets d'interférence quantique sur un schéma électronucléaire. Nous avons montré que pour ce système, un rayon gamma peut être amplifié sans inversion de population. Ce résultat est très important, compte tenu du fait qu'une telle inversion est techniquement impossible à réaliser pour ces très hautes fréquences électromagnétiques, empêchant jusqu'ici la réalisation de lasers gamma. Afin d'atteindre l'amplification sans inversion, un rayonnement d'appoint dans le domaine optique s'avère nécessaire. Tenant compte de la décroissance de ce champ optique en cours de propagation, et donc de la diminution des effets quantiques associés, nous avons déterminé une distance optimale de propagation. Au-delà de cette distance, l'amplification se mue en absorption. Une telle information est dès lors cruciale sur le plan expérimental.
Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished
28
Gesualdi, Marcos Roberto da Rocha. "Estudo de materiais fotorrefrativos e suas aplicações no processamento óptico holográfico de informação." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-28022014-112020/.
Повний текст джерелаАнотація:
O Estudo de Materiais Fotorrefrativos e suas Aplicações no Processamento Óptico Holográfico de Informação vêm sendo feitos por diversos Grupos de Pesquisas em vários laboratórios devido aos bons resultados obtidos com esses meios em diversas áreas. Entre outros efeitos foto-induzidos o processo que possibilita essas aplicações é o efeito fotorrefrativo, um fenômeno onde o registro holográfico no meio fotorrefrativo ocorre pela modulação do índice de refração de acordo com a distribuição espacial da intensidade da luz incidente, devido a uma redistribuição foto-induzida de cargas espaciais, e conseqüente, geração de um campo espaço-carga no meio. Neste trabalho, estuda-se a propagação e acoplamento de ondas eletromagnéticas em monocristais elétro-ópticos paraelétricos da Família das Silenitas \'BI IND. 12\'\'SI\'\'O IND. 20\' (BSO) e \'BI IND. 12\'\'TI\'\'O IND. 20\' (BTO) e nos ferroelétricos \'LI\'\'NB\'\'O IND. 3\' puros e dopados. O propósito de estudar esses materiais é caracterizá-los e, principalmente, otimizá-los para aplicação no processamento óptico e holográfico de informação. Utiliza-se técnicas de caracterização de redes holográficas fotorrefrativas e de lentes foto-induzidas para determinação de figuras de mérito e parâmetros fotorrefrativos e termo-ópticos nestes meios fotorrefrativos. Propõe-se também algumas aplicações no processamento óptico e holográfico de informação, nas áreas de pesquisa básica, tecnológicas e biomédicas, que vêm despertando grande interesse nos últimos anos, como holografia em tempo real com mapeamento de fase, interterometria speckle em tempo real e registro não-holográfico no processo de conversão incoerente-incoerente; entre outras no processamento óptico e holográfico de dados.The Study of Photorefractive Materials and their Applications in Optical and Holographical Information Processing come being made for diverse Groups of Research in some laboratories due to the good results in many areas. Among other photo-induced effects, the process that allows these applications is the photorefractive effect, a phenomenon where the holographic recording in photorefractive medium occurs by means of the refractive index modulation due to the space distribution of the light intensity, producing a space-charge photo-induced redistribution, and consequently, the generation of a space-charge field governed by an electro-optic medium. In this work, we study the propagation and coupling of electromagnetic waves in electro-optic monocrystals of the sillemite family Bi12SiO20 (BSO) and Bi12TiO20 (BTO) and in the pure and dop-ed LiNbO3 crystals. The purpose to study these materials is to characterize them and, mainly, to optimize the conditions of their application in the optical and holographical information processing. We use photorefractive holographic gratings and photo-induced lens techniques for determination of figures of merit and photorefractive and thermo-optic parameters in these photorefractive materials. We also consider some applications in the optical and holographical information processing in the research basic, technological and biomedical areas, that come waken great interest in the last years, as phase- shifting real-time holography, real-time speckle interferometry and non-holographic recording with incoherent-incoherent conversion process; among others in the optic and holographic data processing.
29
Zanzi, Andrea. "Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects." Doctoral thesis, Universitat Politècnica de València, 2020. http://hdl.handle.net/10251/149377.
Повний текст джерелаАнотація:
[EN] Optical technologies are the backbone of modern communication systems providing
high-speed access to the Internet, efficient inter and intra-data center interconnects
and are expending towards growing research fields and new markets such as satel-
lite communications, LIDARs (Laser Imaging Detection and Ranging) applications,
Neuromorphic computing, and programable photonic circuits, to name a few. Be-
cause of its maturity and low-cost, silicon photonics is being leveraged to allow these
new technologies to reach their full potential.As a result, there is a strong need for
innovative, high-speed and energy-efficient photonic integrated building blocks on
the silicon platform to increase the readiness of silicon photonic integrated circuits.
The work developed and presented in this thesis is focused on the design and char-
acterization of advanced passive and active devices, for photonic integrated circuits.
The thesis consists of three main chapters as well as a motivation and concluding
sections exposing the rationale and the accomplishments of this work. Chapter one
describes the design and characterization of an electro-optical Mach-Zehnder mod-
ulator embedded in highly efficient vertical pn junction exploiting the free-carrier
dispersion effect in the O-band.. Chapter two is devoted to the design and charac-
terization of a novel geometry of asymmetrical multimode interference device and
its implementation in a Mach-Zehnder modulator. Chapter three is dedicated to
the design and characterization of innovative 1-dimensional photonic crystal designs
for slow- lightmodulation applications. An extensive analysis of the main trade-off
arising from the use of slow light is presented.[ES] Las tecnologías ópticas son el eje vertebrador de los sistemas de comunicación mod- ernos que proporcionan acceso de alta velocidad a la Internet, interconexiones efi- cientes entre centros de datos y dentro de ellos. Además, se están expandiendo hacia campos de investigación crecientes y nuevos mercados como son las aplicaciones de comunicaciones por satélite, los LIDAR (Laser Imaging Detection and Ranging), la computación neuromórfica y los circuitos fotónicos programables, por nombrar algunos. La fotónica de silicio está considerada y aceptada ampliamente como una de las tecnologías clave para que dichas aplicaciones puedan desarrollarse. Como resultado, hay una fuerte necesidad de estructuras fotónicas básicas integradas que sean innovadoras, que soporten altas velocidades de transmisión y que sean más eficientes en términos de consumo de potencia, a fin de aumentar la capacidad de los circuitos integrados fotónicos de silicio. El trabajo desarrollado y presentado en esta tesis se centra en el diseño y la car- acterización de dispositivos avanzados pasivos y activos, para circuitos fotónicos integrados. La tesis consta de tres capítulos principales, así como de sendas sec- ciones de motivación y conclusiones que exponen los fundamentos y los logros de este trabajo. El capítulo uno describe el diseño y la caracterización de un modulador electro-óptico Mach-Zehnder incorporado en una unión pn vertical altamente eficien- ciente que explota el efecto de dispersión de plasma en banda O. El capítulo dos está dedicado al diseño y caracterización de una nueva geometría de dispositivo de interferencia multimodo asimétrico y su aplicación en un modulador Mach-Zehnder. El capítulo tres está dedicado al diseño y caracterización de innovadores cristales fotónicos unidimensionales para aplicaciones de modulación con luz lenta. Se pre- senta un amplio análisis de los principales retos derivados del uso de la misma.
[CA] Les tecnologies òptiques són l'eix vertebrador d'aquells sistemes de comunicació moderns que proporcionen accés d'alta velocitat a la Internet, així com intercon- nexions eficients inter i entre centres de dades. A més a més, s'estan expandint cap a camps d'investigació creixents i nous mercats com són les aplicacions de co- municacions per satèl·lit, els LIDAR (Laser Imaging Detection and Ranging), la computació neuromòrfica i els circuits fotònics programables, entre d'altres. La fotònica de silici és considerada i acceptada àmpliament com una de les tecnologies clau i necessàries perquè aquestes aplicacions puguen desenvolupar-se. Per aquest motiu, es fa necessària l'existència d'estructures fotòniques bàsiques integrades que siguen innovadores, que suporten altes velocitats de transmissió i que siguen més eficients en termes de consum de potència, a fi d'augmentar la capacitat dels cir- cuits integrats fotònics de silici. El treball desenvolupat i presentat en aquesta tesi se centra en el disseny i la caracterització de dispositius avançats passius i actius, per a circuits fotònics integrats. La tesi consta de tres capítols principals, així com d'una secció de motivació i una altra de conclusions que exposen els fonaments i els assoliments d'aquest treball. El capítol u descriu el disseny i la caracterització d'un modulador electro-òptic Mach-Zehnder incorporat en una unió pn vertical d'alta efi- ciència que explota l'efecte de dispersió de plasma en la banda O. El capítol dos està dedicat al disseny i caracterització d'una nova geometria de dispositiu d'interferència multimode asimètric així com a la seua aplicació en un modulador Mach-Zehnder. El capítol tres està dedicat al disseny i caracterització d'innovadors cristalls fotònics unidimensionals per a aplicacions de modulació amb llum lenta. S'inclou també una anàlisi detallada dels principals reptes derivats de l'ús d'aquest tipus de llum.
I want to thank you the Generelitat Valenciana and the European Project L3MATRIX for the funding, without them my doctorate would not taken place.
Zanzi, A. (2020). Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149377
TESIS
30
Avila, Luis Fernando de 1980. "Estudo de materiais fotossensíveis utilizando exposições holográficas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278205.
Повний текст джерелаАнотація:
Orientador: Lucila Helena Deliesposte CescatoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
Made available in DSpace on 2018-08-15T19:36:27Z (GMT). No. of bitstreams: 1 Avila_LuisFernandode_D.pdf: 1824665 bytes, checksum: 6cab44933ac386ebd3097bd193d85e0f (MD5) Previous issue date: 2010
Resumo: Materiais fotossensíveis são materiais que sofrem alterações físico-químicas quando expostos à luz de comprimento de onda apropriado. A gama de aplicações para estes materiais é enorme, entre elas as que apresentam maiores exigências em termos do próprio material são as aplicações em armazenagem de informação e imagens. Para avaliar o potencial de um material para uma dada aplicação é necessário entender os mecanismos fotossensíveis envolvidos assim como caracterizar suas propriedades, tais como: sensibilidade espectral, modulação óptica máxima, reversibilidade, estabilidade térmica, etc. Nesta tese de doutorado foi proposto e demonstrado um método para processar os sinais de auto-difração que, além de permitir a medida simultânea e independente das modulações de índice de refração e de coeficiente de absorção, nos permite medir a evolução temporal das modulações e a constante cinética das reações fotossensíveis. Esta técnica foi utilizada para estudar três tipos de materiais fotossensíveis: fotorresinas positivas (SC 1827 da Shipley), fotorresinas negativas (SU-8 da Microchem) e vidros calcogenetos (em particular composições com Sulfeto de Antimônio). As medidas foram realizadas utilizando-se dois interferômetros diferentes: um com óptica para o visível e outro para o ultravioleta. Além disso, foi observada uma modulação de elétrons secundários nas imagens de microscopia eletrônica de amostras de fotorresinas negativas SU8 expostas holograficamente
Abstract: Photosensitive materials are materials that change their optical properties when exposed to light of appropriate wavelength. The range of applications of such materials is very wide. Among these applications the storage of images and information is that present higher requirements in terms of the material itself. To evaluate the potential of a material for a given application it is necessary to understand the mechanisms involved as well as to characterize their photosensitive properties such as spectral sensitivity, maximum optical modulation, reversibility, thermal stability, etc. In this thesis we propose and demonstrate a method for processing the selfdiffraction the signals that allows the simultaneous and independent measurement of the modulations of refractive index and absorption coefficient as well as to measure the temporal evolution of such modulations and their corresponding kinetic constant of the photo-reactions. This technique was employed to study three types of photosensitive materials: positive photoresist (SC 1827 from Shipley), negative photoresist (Microchem SU-8) and chalcogenide glasses (in particular compositions with Antimony Sulfide). Measurements were performed using two different interferometers, one with optics for the visible and one for the ultra-violet. Moreover, a modulation of secondary electrons was observed in the electronic microscopy images of the SU8 negative photoresist samples exposed holographically
Doutorado
Ótica
Doutor em Ciências
31
Blecha, Martin. "Pracoviště pro optickou interferometrii." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217262.
Повний текст джерелаАнотація:
This thesis is specialized on composition of workplace for experiments flowing from optical interferometry. Here are described laboratory exercise servant for demonstration basic principles of interferometry. In more details is described method measurement of height profile objects with method white light interferometry.
32
Gao, Ying. "A Digital Signal Processing Approach for Affective Sensing of a Computer User through Pupil Diameter Monitoring." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/132.
Повний текст джерелаАнотація:
Recent research has indicated that the pupil diameter (PD) in humans varies with their affective states. However, this signal has not been fully investigated for affective sensing purposes in human-computer interaction systems. This may be due to the dominant separate effect of the pupillary light reflex (PLR), which shrinks the pupil when light intensity increases. In this dissertation, an adaptive interference canceller (AIC) system using the H∞ time-varying (HITV) adaptive algorithm was developed to minimize the impact of the PLR on the measured pupil diameter signal. The modified pupil diameter (MPD) signal, obtained from the AIC was expected to reflect primarily the pupillary affective responses (PAR) of the subject. Additional manipulations of the AIC output resulted in a processed MPD (PMPD) signal, from which a classification feature, PMPDmean, was extracted. This feature was used to train and test a support vector machine (SVM), for the identification of stress states in the subject from whom the pupil diameter signal was recorded, achieving an accuracy rate of 77.78%. The advantages of affective recognition through the PD signal were verified by comparatively investigating the classification of stress and relaxation states through features derived from the simultaneously recorded galvanic skin response (GSR) and blood volume pulse (BVP) signals, with and without the PD feature. The discriminating potential of each individual feature extracted from GSR, BVP and PD was studied by analysis of its receiver operating characteristic (ROC) curve. The ROC curve found for the PMPDmean feature encompassed the largest area (0.8546) of all the single-feature ROCs investigated. The encouraging results seen in affective sensing based on pupil diameter monitoring were obtained in spite of intermittent illumination increases purposely introduced during the experiments. Therefore, these results confirmed the benefits of using the AIC implementation with the HITV adaptive algorithm to isolate the PAR and the potential of using PD monitoring to sense the evolving affective states of a computer user.
33
Oppel, Steffen [Verfasser], and Joachim von [Akademischer Betreuer] Zanthier. "Multi-Photon Interferences of Independent Light Sources / Steffen Oppel. Betreuer: Joachim von Zanthier." Erlangen : Universitätsbibliothek der Universität Erlangen-Nürnberg, 2013. http://d-nb.info/1029869383/34.
Повний текст джерела
34
Xi, Xiaojun. "New Stochastic Geometry Approaches to the Modeling and Analysis of Low and High Frequency Wireless Communication Networks." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS556.
Повний текст джерелаАнотація:
Dans cette thèse, nous avons développé de nouveaux cadres d'analyse pour analyser et optimiser les futurs réseaux cellulaires à l'aide de la géométrie stochastique et des processus ponctuels. Cette thèse fournit quatre contributions techniques principales.Nous analysons d’abord les réseaux émergents capables de communiquer en utilisant la lumière plutôt que les ondes radio. Dans ce contexte, nous proposons un cadre analytique innovant qui nous permet d’estimer la probabilité de couverture et le débit moyen des réseaux distribués dans l’espace, qui sont utilisés pour mieux comprendre l’optimisation du système.Deuxièmement, nous proposons une méthodologie innovante pour modéliser des réseaux cellulaires spatialement corrélés en utilisant des processus ponctuels non homogènes. L'approche proposée est testée par rapport au déploiement pratique de réseaux cellulaires et s'est révélée pratique et précise. Il est appliqué à l'analyse des réseaux de communication à lumière visible et l'impact de la corrélation spatiale est étudié.Troisièmement, nous abordons le problème ouvert de la modélisation de réseaux cellulaires MIMO massifs. Nous étudions les réseaux cellulaires montants et descendants et proposons de nouvelles limites supérieures et inférieures pour l'efficacité spectrale moyenne, ce qui nous permet d'identifier le nombre optimal d'utilisateurs à desservir dans chaque cellule du réseau et l'impact de plusieurs paramètres clés du système.Quatrièmement, nous présentons et analysons les performances d'un nouvel algorithme de planification prenant en compte les interférences pour une application sur la liaison montante des réseaux cellulaires. L’approche proposée consiste à assourdir certains utilisateurs afin de réduire le niveau d’interférence. La performance réalisable et l'équité utilisateur de l'approche proposée sont discutées et quantifiées analytiquementIn this thesis, we have developed new analytical frameworks for analyzing and optimizing future cellular networks with the aid of stochastic geometry and point processes. This thesis provides four main technical contributions.First, we analyze emerging networks that can communicate by using light instead of radio waves. In this context, we propose an innovative analytical framework that allows us to estimate the coverage probability and the average rate of spatially distributed networks, which are used to gain insight for system optimization.Second, we propose an innovative methodology for modeling spatially correlated cellular networks by using inhomogeneous point processes. The proposed approach is tested against practical deployment of cellular networks and found to be tractable and accurate. It is applied to the analysis of visible light communication networks, and the impact of spatial correlation is studied.Third, we tackle the open problem of modeling Massive MIMO cellular networks. We study uplink and downlink cellular networks and propose new upper and lower bounds for the average spectral efficiency, which allow us to identify the optimal number of user to serve in each cell of the network and the impact of several key system parameters.Fourth, we introduce and analyze the performance of a new interference-aware scheduling algorithm for application to the uplink of cellular networks. The proposed approach is based on muting some users in order to reduce the level of interference. The achievable performance and the user-fairness of the proposed approach are discussed and quantified analytically
35
Puthumpally, Joseph Raijumon. "Quantum Interferences in the Dynamics of Atoms and Molecules in Electromagnetic Fields." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS035/document.
Повний текст джерелаАнотація:
Les interférences quantiques apparaissant lors de la superposition cohérente d'états quantiques de la matière sont à l'origine de la compréhension et du contrôle de nombreux processus élémentaires. Dans cette thèse, deux problèmes distincts, qui ont pour origine de tels effets, sont discutés avec leurs applications potentielles : 1. Diffraction électronique induite par Laser (LIED) et imagerie des orbitales moléculaires ; 2. Effets collectifs dans des vapeurs denses et transparence électromagnétique induite par interaction dipôle-dipôle (DIET). La première partie de cette thèse traite du mécanisme de recollision dans des molécules linéaires simples lorsque le système est exposé à un champ laser infrarouge de forte intensité. Cette interaction provoque une ionisation tunnel du système moléculaire, conduisant à la création d'un paquet d'ondes électronique dans le continuum. Ce paquet d'ondes suit une trajectoire oscillante, dirigée par le champ laser. Cela provoque une collision avec l'ion parent qui lui a donné naissance. Ce processus de diffraction peut être de nature inélastique, engendrant la génération d'harmoniques d'ordre élevé (HHG) ou l'ionisation double non-séquentielle, ou de nature élastique, processus que l'on appelle généralement « diffraction électronique induite par laser ». La LIED porte des informations sur la molécule et sur l'état initial à partir duquel les électrons sont arrachés sous forme de motifs de diffraction formés en raison de l'interférence entre différentes voies de diffraction. Dans ce projet, une méthode est développée pour l'imagerie des orbitales moléculaires, reposant sur des spectres de photo-électrons obtenus par LIED. Cette méthode est basée sur le fait que la fonction d'ondes du continuum conserve la mémoire de l'objet à partir duquel elle a été diffractée. Un modèle analytique basé sur l'approximation de champ fort (SFA) est développé pour des molécules simples linéaires et appliqué aux orbitales moléculaires HOMO et HOMO-1 du dioxyde de carbone. L'interprétation et l'extraction des informations orbitalaires imprimées dans les spectres de photo-électrons sont présentées en détail. Par ailleurs, nous estimons que ce type d'approche pourrait être étendu à l'imagerie de la dynamique électro-nucléaire de tels systèmes. La deuxième partie de cette thèse traite des effets collectifs dans des vapeurs atomiques ou moléculaires denses. L'action de la lumière sur ces gaz crée des dipôles induits qui oscillent et produisent des ondes électromagnétiques secondaires. Lorsque les particules constitutives du gaz sont assez proches, ces ondes secondaires peuvent coupler les dipôles induits entre-eux, et lorsque cette corrélation devient prépondérante la réponse du gaz devient une réponse collective. Ceci conduit à des effets spécifiques pour de tels systèmes, comme l'effet Dicke, la superradiance, et les décalages spectraux de Lorentz-Lorenz ou de Lamb. A cette liste d'effets collectifs, nous avons ajouté un effet de transparence induite dans l'échantillon. Cet effet collectif a été appelé « transparence électromagnétique induite par interaction dipôle-dipôle ». La nature collective de l'excitation du gaz dense réduit la vitesse de groupe de la lumière transmise à quelques dizaines de mètre par seconde, créant ainsi une lumière dite « lente ». Ces effets sont démontrés pour les transitions D1 du 85Rb et d'autres applications potentielles sont également discutéesQuantum interference, coherent superposition of quantum states, are widely used for the understanding and engineering of the quantum world. In this thesis, two distinct problems that are rooted in quantum interference are discussed with their potential applications: 1. Laser induced electron diffraction (LIED) and molecular orbital imaging, 2. Collective effects in dense vapors and dipole induced electromagnetic transparency (DIET). The first part deals with the recollision mechanism in molecules when the system is exposed to high intensity infrared laser fields. The interaction with the intense field will tunnel ionize the system, creating an electron wave packet in the continuum. This wave packet follows an oscillatory trajectory driven by the laser field. This results in a collision with the parent ion from which the wave packet was formed. This scattering process can end up in different channels including either inelastic scattering resulting in high harmonic generation (HHG) and non-sequential double ionization, or elastic scattering often called laser induced electron diffraction. LIED carries information about the molecule and about the initial state from which the electron was born as diffraction patterns formed due to the interference between different diffraction pathways. In this project, a method is developed for imaging molecular orbitals relying on scattered photoelectron spectra obtained via LIED. It is based on the fact that the scattering wave function keeps the memory of the object from which it has been scattered. An analytical model based on the strong field approximation (SFA) is developed for linear molecules and applied to the HOMO and HOMO-1 molecular orbitals of carbon dioxide. Extraction of orbital information imprinted in the photoelectron spectra is presented in detail. It is anticipated that it could be extended to image the electro-nuclear dynamics of such systems. The second part of the thesis deals with collective effects in dense atomic or molecular vapors. The action of light on the vapor samples creates dipoles which oscillate and produce secondary electro-magnetic waves. When the constituent particles are close enough and exposed to a common exciting field, the induced dipoles can affect one another, setting up a correlation which forbids them from responding independently towards the external field. The result is a cooperative response leading to effects unique to such systems which include Dicke narrowing, superradiance, Lorentz-Lorenz and Lamb shifts. To this list of collective effects, one more candidate has been added, which is revealed during this study: an induced transparency in the sample. This transparency, induced by dipole-dipole interactions, is named “dipole-induced electromagnetic transparency”. The collective nature of the dense vapor excitation reduces the group velocity of the transmitted light to a few tens of meter per second resulting in 'slow' light. These effects are demonstrated for the D1 transitions of 85Rb and other potential applications are also discussed
36
Claveau, Rémy. "Caractérisation spectrale locale à l'aide de la microscopie interférométrique : simulations et mesures." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAD037/document.
Повний текст джерелаАнотація:
La microscopie interférométrique est une méthode de mesure qui repose sur l’acquisition et le traitement du signal issu de l’interaction de deux ondes, dites ondes « objet » et de « référence ». Ces ondes proviennent des réflexions de la lumière sur un miroir de référence et sur l’échantillon étudié. Bien qu’étant généralement utilisées pour les analyses topographiques ou tomographiques d’un échantillon, les données interférométriques peuvent être exploitées pour réaliser des caractérisations spectrales locales résolues dans les trois directions de l’espace. Dans ce projet, nous avons étudié les performances de cette technique ainsi que ses limitations lorsque l’échantillon se complexifie (dégradation du signal d’interférences). L’analyse a été appliquée à des matériaux réfléchissants pour des mesures en surface puis à des couches transparentes et diffusantes pour aller sonder le milieu en profondeur et extraire la réponse spectrale individuelle de structures localisées dans ce milieuWhite light interference microscopy is a measurement method based on the acquisition and processing of the signal coming from the interaction between two wave fronts, known as the “object” and “reference” wave-fronts. These waves come from the reflection of the light on a reference mirror and the sample studied. Usually used for topographic or tomographic analysis of a sample, the interferometric data can be exploited for spectroscopic purposes. The resulting spectral characterizations are spatially resolved in the three directions of space. In this project, we have studied the performance of this technique, as well as the associated limitations when the sample becomes more complex (degradation of the interferometric signal). The analysis has been first applied to reflective materials for surface measurements and subsequently to transparent and scattering layers for probing within the depth of the medium and then extracting the individual spectral response of the buried structures
37
Bookjans, Eva M. "Relative number squeezing in a Spin-1 Bose-Einstein condensate." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37148.
Повний текст джерелаАнотація:
The quantum properties of matter waves, in particular quantum correlations and entanglement are an important frontier in atom optics with applications in quantum metrology and quantum information. In this thesis, we report the first observation of sub-Poissonian fluctuations in the magnetization of a spinor 87Rb condensate. The fluctuations in the magnetization are reduced up to 10 dB below the classical shot noise limit. This relative number squeezing is indicative of the predicted pair-correlations in a spinor condensate and lay the foundation for future experiments involving spin-squeezing and entanglement measurements. We have investigated the limits of the imaging techniques used in our lab, absorption and fluorescence imaging, and have developed the capability to measure atoms numbers with an uncertainly < 10 atoms. Condensates as small as ≈ 10 atoms were imaged and the measured fluctuations agree well with the theoretical predictions. Furthermore, we implement a reliable calibration method of our imaging system based on quantum projection noise measurements. We have resolved the individual lattice sites of a standing-wave potential created by a CO2 laser, which has a lattice spacing of 5.3 µm. Using microwaves, we site-selectively address and manipulate the condensate and therefore demonstrate the ability to perturb the lattice condensate of a local level. Interference between condensates in adjacent lattice sites and lattice sites separated by a lattice site are observed.
38
Rogosch, Dorothee. "Depletion des Myc-interagierenden Zinkfingerproteins 1 mittels RNA-Interferenz und die Rolle von Miz-1 in der zellulären DNA-Schadensantwort auf UV-Licht." [S.l.] : [s.n.], 2006. http://archiv.ub.uni-marburg.de/diss/z2006/0290.
Повний текст джерела
39
Li, Cheng Han, and 李丞瀚. "An Adaptation Scheme to Ambient Light Interference for Visible Light Communication Link." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/87746619335013252081.
Повний текст джерела
40
Coetzee, Annaretha. "Alternative conceptions concerning interference and diffraction of light." Thesis, 1998. http://hdl.handle.net/10539/22841.
Повний текст джерелаАнотація:
A research report submitted in partial fulfillment of the requirements for the degree of
Master of Science in Education at the Faculty of Science, University of the Witwatersrand, Johannesburg.The aim of this study was to determine whether alternative conceptions about interference and diffraction do indeed exist, to identify the most important of these conceptions and to determine whether these conceptions relate to textbooks, as one of the main sources of students' knowledge. An analysis of secondary level textbooks and tertiary level non-calculus textbooks revealed that presentations of constructive and destructive interference, diffraction and other related aspects are treated inconsistently and in some cases contradictorily by different authors. The research instrument was a Physical Optics test which Physics students of the Technikon Pretoria wrote. This test revealed that alternative conceptions on elementary principles of interference and diffraction of light do exist and that they relate to textbook presentations. This study reveals that (i) the terms in phese and out of phase are not consistently used in different textbooks; (ii) the definitions of constructive and destructive interference in terms of phases cause major aiternative conceptions, (iii) the interrelation between interference and diffraction is not clarified.
AC2017
41
Coetzee, Annaretha. "Alternative conceptions concerning interference and diffraction of light." Thesis, 2014.
Знайти повний текст джерелаАнотація:
Thesis (M.Sc. (Science Education))--University of the Witwatersrand, Faculty of Science, 1998.The aim of this study was to determine whether alternative conceptions about interference and diffraction do indeed exist, to identify the most important of these conceptions and to determine whether these conceptions relate to textbooks, as one of the main sources of students’ knowledge. An analysis of secondary level textbooks and tertiary level non-calculus textbooks revealed that presentations of constructive and destructive interference, diffraction and other related aspects are treated inconsistently and in some cases contradictorily by different authors. The research instrument was a Physical Optics test which Physics students of the Technikon Pretoria wrote. This test revealed that alternative conceptions on elementary principles of interference and diffraction of light do exist and that they relate to textbook presentations. This study reveals that (i) the terms in phase and out of phase are not consistently used in different textbooks; (ii) the definitions of constructive and destructive interference in terms of phases cause major alternative conceptions; (iii) the interrelation between interference and diffraction is not clarified.
42
Chen, Shin Hung, and 陳信宏. "Interference patterns in the spectra of light-emitting diode." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/64322518029686233450.
Повний текст джерелаАнотація:
碩士長庚大學
光電工程研究所
98
This work studies the interference patterns surface and edge spectra of AlGaInP and nitride light-emitting diodes device. By measuring surface and backside spectra of nitride sample, we discover the phenomenon of interference patterns spectra does not cause by filtering effect. The interference is attributed to the modulation of the spontaneous emission rather than the filtering effect of an optical thin film. We also discover the spontaneous emission rates are controllable. The radiation rate can be tune through the change of the optical field distribution. We cannot utilize the EM wave solution of Maxwell equation to describe the spontaneous emissions. Therefore, by measuring the photocurrent and emission spectra of AlGalnP device know the structural corresponding to the absorption and emission rate. At the same time, we also simulate the optical field distribution of EM wave. When the quantum well electron-hole pair dipole formed interaction strongly with the optical field, the absorption rate of EM waves are enhanced, the emission rate are enhanced too. On the other hand, the emission rates decrease follow the optical fields reduce. In conclusion, we know the modulation of emission spectra is the interference patterns. We know the attribution of surface interference spectra and base on the theorem to measure the spectra of vary angle of nitride sample. We find the edge spectra of nitride are attributed to the surface high angle equivalent interference patterns. And the interference patterns cycle increase with the emission angle. The result corresponds with the simulation and also demonstrates the optical resonator model
43
Shi, Sheng-Wen, and 施勝文. "Line-scan profilometer using broadband light source interference pattern." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/4kaz3t.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
光電工程系研究所
105
This research proposes a line-scan profilometer using broadband light source interference pattern. It containsan interference module, a stage, an object under test, and a light detection module. Wherein, the interference module projects a broadband source interference pattern on the object, the light detection module captures the image of the projection, and the profilometer reconstructs the contours of the object by examining the displacement of the zeroth-order fringe of the interference pattern while the object is scanned vertically orthe interference pattern is shifted transversely. This research also verifies the profilometer using experiments, the results not only confirm its validity but also exhibit a high measurement repeatability.
44
Shen, Yen-Jie, and 沈彥傑. "Measuring step height by using Linnik type low coherent light interference." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/13390596906328173032.
Повний текст джерелаАнотація:
碩士明道大學
光電暨能源工程學系碩士班
99
The purpose of the work was to set up a microscopy interferometer and measuring step height by using low coherence light interferometry . A Super Luminescent Diode, SLD was used as the light source , and the center wavelength of SLD is 844.8 nm and coherence length is 15.38 μm . A Linnk type microscope interferometer was set up , and the interference fringe ‘s variation was measured while shifting the sample by PZT. The interference fringe was analyzed by using Fourier Transform Method to obtain the step height , and it was discovered that while the samples with thin film and step height , the step height and the thickness of the thin film could be determined simultaneously. In conclusion, we discovered that the image of the sample could be viewed by using the Linnk type microscope interferometer set up in this research
45
CHUNG, I.-HAO, and 鍾宜豪. "Wide-field White-light Interference Microscopy for 3D Color Surface Measurement." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/87cfck.
Повний текст джерелаАнотація:
碩士逢甲大學
光電學系
106
In this study, we have successfully extended the capability of traditional scanning white-light interference microscopy (SWIM) to wide-field 3D color surface measurement. The new SWIM system uses a color CCD to record interference images. The outputs of the CCD are three RGB interferograms. In order to maintain high axial resolution, the RGB interference images are combined to generate one white-light interferogram. The surface profile of a tested sample is restored via vertical scanning and centroid methods. The colors of the sample are the average values of RGB interference signals near zero optical path difference. The field of view is broadened by stitching many surface-profiles together. Every two adjacent fields overlap partially. The heights of the overlapped regions are corrected according to plane-fitting results. Finally, we use least root-mean-square error of the height difference between the overlapped areas for determining the offset along X and Y directions of two adjacent fields. 3×3-field measurements with this new SWIM were performed on multiple samples, the system is proved very effective in measuring wide-field 3D color surface. The measurement area is increased by 6 times compared with the conventional white-light interference microscope.
46
Su, Yuan-Jun, and 蘇緣峻. "Interference Rejection Using Filter-Based Sensor Array for Visible Light Communication Systems." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/933647.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電機工程系所
99
The goal of this thesis is to research into multi-antenna diversity techniques for spectrum sensor array receiver in visible light communication systems and to improve the performance of this system. Conventionally, photoelectric-diodes are implemented to convert optical signals into electronic signals. Since conventional photoelectric-diodes cannot distinguish inputs of different spectra, using conventional photoelectric-diodes have the disadvantage that the system is vulnerable to interference and noise, and hard to achieve wavelength division multiplexing (WDM) for light sources of different wavelengths. In this work, a spectrum sensor array is proposed to be implemented on the receiver side to achieve interference and noise rejection. By proper design of the weightings for individual spectrum sensor, the effective output signal-to-noise ratio (SNR) or signal-to-interference ratio (SIR) or signal-to-interference-plus-noise ratio (SINR) can be maximized. Following the concept of multi-antenna communication systems, signal fusion algorithms include maximum SINR combining (MSC), maximum ratio combining (MRC), equal gain combining (EGC), selection combining (SC) and matched filter combining (MFC) are presented. The simulation results demonstrate robust interference and noise rejection is made possible using the low-cost spectrum sensor array.
47
"Optical Simulation and Optimization of Light Extraction Efficiency for Organic Light Emitting Diodes." Master's thesis, 2016. http://hdl.handle.net/2286/R.I.38677.
Повний текст джерелаАнотація:
abstract: Current organic light emitting diodes (OLEDs) suffer from the low light extraction efficiency. In this thesis, novel OLED structures including photonic crystal, Fabry-Perot resonance cavity and hyperbolic metamaterials were numerically simulated and theoretically investigated. Finite-difference time-domain (FDTD) method was employed to numerically simulate the light extraction efficiency of various 3D OLED structures. With photonic crystal structures, a maximum of 30% extraction efficiency is achieved. A higher external quantum efficiency of 35% is derived after applying Fabry-Perot resonance cavity into OLEDs. Furthermore, different factors such as material properties, layer thicknesses and dipole polarizations and locations have been studied. Moreover, an upper limit for the light extraction efficiency of 80% is reached theoretically with perfect reflector and single dipole polarization and location. To elucidate the physical mechanism, transfer matrix method is introduced to calculate the spectral-hemispherical reflectance of the multilayer OLED structures. In addition, an attempt of using hyperbolic metamaterial in OLED has been made and resulted in 27% external quantum efficiency, due to the similar mechanism of wave interference as Fabry-Perot structure. The simulation and optimization methods and findings would facilitate the design of next generation, high-efficiency OLED devices.Dissertation/Thesis
Masters Thesis Mechanical Engineering 2016
48
Huang, Yung-Kuo, and 黃永國. "Inspection of 3D Profile and Internal Structure with Polarized Low Coherent Light Interference Microscope." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/93011580853076290987.
Повний текст джерелаАнотація:
博士國立中正大學
機械工程所
94
Abstract In this paper, we set up a polarized sensitivity optical coherence tomography microscope (PS-OCM) of Linnik type. This PS-OCM was modified mechanism of the reference arm in order to compensate the difference of optical path. So the microscope can achieve the function of white light interference microscope (WLI), virtual confocal microscope and the PS-OCM. The resolution of WLI reached to nanometers scale. So it is indispensable to MENS or semiconductor manufacture procedure. The optical tomography had the functions which was transparent material internal structure measured and bio-tissue internal imaging. Therefore, it was increasingly attach importance to field of optical inspection except field of biotechnology. Additionally, OCM will inspect the birefringence, when the OCM used the polarization light source. Inspection of 3D profile with this PS-OCM, we developed a new scanning algorithm. This algorithm combined Hilbert transform to search the zero order fringe of the interferogram. And measure a 3D profile standard to prove the correctness of the algorithm. The PS-OCM can execute the function of microscope, and this paper develops a virtual confocal algorithm. Use this algorithm, the PS-OCM except inspected 3D profile and provide the full depth of field image of the sample. The PS-OCM can measure the internal structure of transparent material which operated with the mechanism of optical difference compensated. And the paper drove an equation of optical difference compensated which regulated the displacement of the compensation mechanism. Because, the sample arm of the PS-OCM would be longer when focus fall in transparent material internal. So, this PS-OCM is unrestricted with the depth of field of objective on the depth of measurement. Finally, we demonstrate a measurement of the stress induce birefringence with the PS-OCM.
49
楊音光. "Design and development of real-time light shape monitor system of laser interference lithography." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/44974939267411994160.
Повний текст джерела
50
徐世雄. "A Study of White Light Interference Detection System Based on Texture Analysis and Fuzzy Theory." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/49987220331287206316.
Повний текст джерелаАнотація:
碩士國立交通大學
電控工程研究所
99
Among the many high-tech industries, such as semiconductors, flat panel displays, optical communications, MEMS, biomedical and electronic packaging, the micro-structure of the surface contour determines the accuracy of product performance and function in its manufacturing process units are required for the micro- structure of the surface contour to conduct quality monitoring. As most of the three-dimensional white light interferometer detection system algorithms, most only consider the fixed relationship between the pixels in each image, that is, taking into account only the vertical direction, so there is no perfect approach to the use of white light interference of the texture features. Discussed in this paper three-dimensional white light interferometer detection system algorithms, taking into account the use of white light interference of regional texture features, the use of texture analysis, image processing and fuzzy theory can filter the data points in addition to non-interference effects, and reduce errors caused by noise height data. Capability of vertical resolution up to 0.1μm, measured repeatedly degrees up to 2μm, and have a variety of detection for the off poor height, angle, area, volume, coarse degree, ups and downs as well as film thickness and other requirements, to provide a sperm does the testing program .