Dissertations / Theses on the topic 'Infrared applications'
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1
Bone, Stewart A. "Analytical applications of infrared spectroscopy." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385929.
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Liu, Xianliang. "Infrared Metamaterial Absorbers: Fundamentals and Applications." Thesis, Boston College, 2013. http://hdl.handle.net/2345/3829.
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Thesis advisor: Willie J. PadillaRealization of an ideal electromagnetic absorber has long been a goal of engineers and is highly desired for frequencies above the microwave regime. On the other hand, the desire to control the blackbody radiation has long been a research topic of interest for scientists--one particular theme being the construction of a selective emitter whose thermal radiation is much narrower than that of a blackbody at the same temperature. In this talk, I will present the computational and experimental work that was used to demonstrate infrared metamaterial absorbers and selective thermal emitters. Based on these work, we further demonstrate an electrically tunable infrared metamaterial absorber in the mid-infrared wavelength range. A voltage potential applied between the metallic portion of metamaterial array and the bottom ground plane layer permits adjustment of the distance between them thus altering the electromagnetic response from the array. Our device experimentally demonstrates absorption tunability of 46.2% at two operational wavelengths. Parts of this thesis are based on unpublished and published articles by me in collaboration with others. The dissertation author is the primary researcher and author in these publications. The text of chapter two, chapter five, and chapter seven is, in part, a reprint of manuscript being prepared for publication. The text of chapter three is, in part, a reprint of material as it appears in Physical review letters 104 (20), 207403. The text of chapter four is, in part, a reprint of material as it appears in Physical Review Letters 107 (4), 45901. The text of chapter six is, in part, a reprint of material as it appears in Applied Physics Letters 96, 011906
Thesis (PhD) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Physics
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Kitchin, Matthew Roger. "Theory of semiconductor heterostructures for infrared applications." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300192.
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Geyer, Scott Mitchell. "Science and applications of infrared semiconductor nanocrystals." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62053.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2010.Vita. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 149-158).
In this work we study several applications of semiconductor nanocrystals (NCs) with infrared band gaps. In the first half, we explore the physics of two systems with applications in NC based photovoltaics. The physics of mixed films of CdTe and CdSe NCs is studied in chapter 2 as a model for NC based bulk heterojunction photovoltaics. We demonstrate that the presence of an active electron trap on the CdTe dramatically reduces the electron mobility in mixed films. The trapping state is linked to oxidation of the CdTe NCs. A cadmium oleate treatment is shown to reduced the oxidation rate. In chapter 3, we present a method to switch the carrier type of InAs NCs deposited in a thin film from p-type to n-type by the addition of cadmium. This provides a stable pre-deposition technique to control the NC carrier type and is a step towards pn homojunction based NC devices. We discuss the role that surface passivation and substitution doping may play in determining the carrier type. The second half explores the use of NCs for photodetector applications. Chapter 4 presents our efforts to move from a single pixel, proof of principle PbS NC infrared detector to a large area infrared imaging camera. A method to control the resistivity of the NC film through oxidation and re-treatment with ethanedithiol is presented. This allows for integration of our NC film with existing read out technology. The noise spectrum is shown to be dominated by 1/f noise and the dependence of the noise on the bias and channel length is determined. The detectivity is found to be determined by the carrier lifetime and dark current carrier density. In chapter 5, we demonstrate efficient UV-IR dual band detectors based on luminescent down conversion. In this design, NCs absorb UV light and re-emit the light in the infrared band of an InGaAs detector. The high quantum yields of infrared nanocrystals and unique absorption profile are shown to provide a significant advantage over organic dyes. The bandwidth of the detectors is measured and the effect of the down conversion layer on the spatial resolution is characterized.
by Scott Mitchell Geyer.
Ph.D.
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Matthews, Amy L. "Applications of infrared fibers in temperature sensing." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45909.
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As attenuation in silica based fibers approaches its ultimate theoretical limit, investigation is in progress to develop new materials which exhibit lower losses than silica. These bulk materials could then be used to fabricate ultralow loss optical fibers which operate farther out in the infrared than do silica fibers. Such infrared fibers could be used in long, repeaterless telecommunications links, the transmission of CO and CO2 laser power, and in several sensing mechanisms. This thesis presents an overview of these new fibers and how they can be applied in noncontact temperature measurement. Fiber optic temperature sensing is thus reviewed, and an optical fiber pyrometer is discussed.
Master of Science
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Chan, Kin Foong. "Pulsed infrared laser ablation and clinical applications /." Digital version:, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992765.
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Bashir, Zareen. "Applications of near infrared spectroscopy in cerebral monitoring." Thesis, University of Manchester, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488409.
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Amrania, Hemmel. "Ultrafast Mid-Infrared Spectroscopic Imaging with Biomedical Applications." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526408.
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Cummings, Beth L. "Applications of infrared laser spectroscopy to breath analysis." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:5b6e0624-5982-457c-b13c-61484bace371.
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The work presented in this thesis is concerned with development of spectroscopic detection methods based on absorption spectroscopy using semiconductor lasers, with particular ref- erence to the field of medical diagnostics through breath analysis. The first part of this thesis deals with the design and testing of a prototype analyser for simultaneous monitoring of the exchange gases O2 , CO2 and H2O in breath. The aim of this analyser is to provide information required to monitor respiration, with potential use in intensive care monitoring or during anaesthesia. The relatively high concentrations of these gases in breath and read- ily available diode laser sources make detection in the near-infrared (NIR) ideal. However, the relatively weakly absorbing A-band O2 transitions at 760 nm require the application of a sensitive spectroscopic method, cavity enhanced absorption spectroscopy (CEAS). In contrast, CO2 and H2O are monitored using direct single pass absorption spectroscopy, with transitions arising from the 2ν1 + ν3 band at 2 μm and ν1 + ν3 band at 1.3 μm, respectively. It has been demonstrated that these gases can be detected simultaneously over a short pathlength (2.74 - 4 cm) in the respiratory flow by combining various spectroscopic methodologies and real-time data analysis. This analyser is shown to offer a viable alter- native for monitoring respiration, exhibiting absolute detection limits of changes of 0.26 % O2 , 0.02 % CO2 and 0.003 % H2O with a 10 ms time resolution, which are comparable to current mass spectrometry based methods, but without their inherent delays. Following this, investigations into the detection of the main gas constituents in breath in the NIR employing noise-reduction modulation based spectroscopic techniques, namely wavelength and frequency modulation (WMS and FMS respectively) are also reported. The described WMS studies on water at 1.37 μm provide a demonstration of conventional WMS detection, as well as a “proof-of-principle” example of a relatively new approach to calibrating the non-absolute information obtained from a WMS absorption signal. Typically WMS spectra are calibrated using mixtures of known gas concentrations or an absolute direct absorption spectrum where possible. In this work however, a self-calibrating method, the phasor decomposition method (PDM), is employed and the returned concentration from this calibration is compared to direct absorption measurement. From this, the calculated concentration using the PDM is found to differ by 9 % from the concentration value obtained by direct absorption, providing an alternative method of calibration for when direct absorption measurements are not possible. The use of FMS in the NIR is also demonstrated as a potential alternative to CEAS for monitoring O2 at 760 nm. FMS detection is performed on atmospherically broadened O2 and a time-normalised αmin(t) of 2.45 ×10−6 cm−1 s1/2 is obtained, which is two orders of magnitude less sensitive than the value of αmin(t) = 2.35 ×10−8 cm−1 s1/2 obtained with CEAS. This combined with the experimental requirements of an FMS system, make its use for detection of O2 a less practicable option compared to CEAS for real-time breath analysis. The latter work in this thesis involves a change in focus to detection of trace gases in breath in the mid-infrared (MIR). The move of spectroscopic detection to the MIR exploits the larger absorption cross-sections available in this region, and to achieve this, a relatively new form of semiconductor laser, the quantum cascade laser (QCL) is used. The design of a continuous wave QCL spectrometer at 8 μm and its operating characteristics are demon- strated and improvements in its performances are also discussed. This QCL system is then utilised to demonstrate the potential of monitoring species in breath, namely the narrow- band absorber methane and the broadband absorber acetone, taking into consideration the potential interference from other absorbing species in breath and the different spectroscopic characteristics exhibited by these molecules. Finally, the potential to further improve the sensitive detection of trace gases in breath in the MIR is also investigated with studies on the use of CEAS and multipass cells. In this work, the molecule of interest is the biomarker OCS, using transitions of the 2ν2 band at 1031 cm−1 , that are probed using a 10 μm QCL. The application of CEAS in the MIR is not as well developed as in the NIR, and the experimental consequences of using optical cavities at these wavelengths, where equipment tends to be more limited, are investigated and sensitivities discussed in the context of other literature. The experimental procedure of optimising a cavity for CEAS using the off-axis alignment method is also studied in detail, as well as the addition of WMS to further improve the signal quality. An effective absorption pathlength of ∼ 100 m was achieved in the cavity, with a bandwidth reduced αmin(BW) of 1.7 ×10−7 cm−1 Hz−1/2 using WMS CEAS achieved. With the poorer quality optics and limitations in equipment in the MIR for CEAS experiments, the use of a multipass cell, a 238 m Herriott cell, is also investigated as an alternative to the use of an optical cavity at 10 μm. Detection of OCS using direct absorption and WMS is demonstrated in the Herriott cell, achieving αmin(BW) = 2.03×10−8 cm−1 Hz−1/2 using WMS. This shows an improvement in sensitivity compared to WMS CEAS, and also shows the potential for future work on biomarker detection, as it approaches the ∼ ppb levels required for breath analysis.
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Fullager, Daniel B. "Theory, Characterization and Applications of Infrared Hyperbolic Metamaterials." Thesis, The University of North Carolina at Charlotte, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10267303.
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Hyperbolic Metamaterials (HMMs) are engineered structures capable of supporting lightmatter interactions that are not normally observed in naturally occuring material systems. These unusual responses are enabled by an enhancement of the photonic density of states (PDOS) in the material. The PDOS enhancement is a result of deliberately introduced anisotropy via a permittivity sign-change in HMM structures which increases the number and frequency spread of possible wave vectors that propagate in the material. Subwavelength structural features allow effective medium theories to be invoked to construct the k-space isofrequency quadratic curves that, for HMMs, result in the k-space isofrequency contour transitioning from being a bounded surface to an unbounded one. Since the PDOS is the integral of the differential volume between k-space contours, unbounded manifolds lead to the implication of an infinite or otherwise drastically enhanced PDOS. Since stored heat can be thought of as a set of non-radiative electromagnetic modes, in this dissertation we demonstrate that HMMs provide an ideal platform to attempt to modify the thermal/IR emissivity of a material. We also show that HMMs provide a platform for broadband plasmonic sensing. The advent of commercial two photon polymerization tools has enabled the rapid production of nano- and microstructures which can be used as scaffolds for directive infrared scatterers. We describe how such directive components can be used to address thermal management needs in vacuum environments in order to maximize radiative thermal transfer. In this context, the fundamental limitations of enhanced spon- taneous emission due to conjugate impedance matched scatterers are also explored. The HMM/conjugate scatterer system’s performance is strongly correlated with the dielectric function of the negative permittivity component of the HMM. In order to fully understand the significance of these engineered materials, we examine in detail the electromagnetic response of one ternary material system, aluminium-doped zinc oxide (AZO), whose tuneable plasma frequency makes it ideal for HMM and thermal transfer applications. This study draws upon first principle calculations from the open literature utilizing a Hubbard-U corrected model for the non-local interaction of charge carriers in AZO crystalline systems. We present the first complete dielectric function of industrially produced AZO samples from DC to 30,000 cm –1 and conclude with an assessment of this material’s suitability fo the applications described.
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Grigoleto, Hayashi Juliano. "Wire Array Infrared Metamaterial Fibres: Fabrication and Applications." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17790.
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Metamaterials are artificial composite materials that exhibit exotic properties due to their components and sub-wavelength structure. During the past decades, several new materials have emerged from this research field with exciting new optical properties and applications. However, the fabrication of certain meta-structures remains a challenge, particularly with low cost and in large volumes. Fibre drawing is an attractive alternative to overcome such problems, but currently fabrication constraints restrict the size of the metal/dielectric drawn structures, limiting their operation to THz frequencies. In this context, this thesis concerns the fabrication, characterization, and use of new soft-glass based wire array metamaterials fibres for applications in the infrared. Numerical modelling of wire array structures is presented to understand which material combinations and structural parameters are more appropriate for infrared metamaterial fibres. The co-drawing process used is described, focusing on the adaptations used to minimize fluctuation of the structure due to fluid dynamics. Metamaterial fibres with uniform structures containing wire diameter and spacing on the order of few hundreds of nm are produced, which are compatible with operation at mid-infrared frequencies. The fabrication of metamaterial fibre tapers with steep transitions, generating hyperlenses, is also demonstrated. Far field imaging is attempted and the challenges regarding subdiffraction imaging are discussed. Feasible alternatives for future far field super-resolution imaging are proposed based on our numerical modelling and the typical structural transitions fabricated. Since the operational range of our hyperlenses is not limited to the infrared, subdiffraction focusing of 1/176 of the operational wavelength is reported at THz frequencies, achieved by combining a polymer hyperlens with our new infrared hyperlens.
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Cowley, Richard D. "The clinical applications of near infrared spectroscopy (NIRS)." Thesis, University of Manchester, 2003. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488355.
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Oppenheimer, Clive. "Volcanology from space : applications of infrared remote sensing." Thesis, Open University, 1991. http://oro.open.ac.uk/57337/.
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Remote sensing techniques are being used increasingly to address volcanological problems. This thesis is concerned with the interpretation of multispectral infrared data of volcanic thermal features. Data from the two short wavelength infrared (SWIR) bands of the Landsat Thematic Mapper (TM) are used to constrain sizes and temperatures of subpixel resolution hot spots. Analysis of a 1989 TM scene of Lonquimay volcano suggests a cooling from 250 to 170°C of the crust of an active lava flow down 1.5 km of its length. Estimates of the summed radiative and convective heat losses from the flow top fall from 6 to 3 MW per 30 x 30 m pixel downflow. Thermal data were collected at volcanoes in Chile, Nicaragua and Italy to test assumptions explicit in such calculations. These surveys suggest that SWIR emission from fumarole fields is dominated by that from the interior walls of vents, and that surface temperatures around fumarole vents are lower than those of typical active lava bodies. The relative response of the two SWIR sensors of the TM is sensitive to such differences and therefore provides a basis for the interpretation of thennal anomalies known only from satellite data. Comparison of measurements in the two SWIR bands is petfonned with fourteen TM scenes recorded between 1984 and 1991, of a persistent hot spot at Lascar volcano, Chile. Evolution of the thennal source is charted by comparing the summed spectral radiance in each of the SWIR bands. Thus it appears that Lascar has experienced at least two periods of lava dome growth punctuated by the explosive eruptions of 1986 and 1990. Infrared sensors to be deployed on forthcoming remote sensing platfonns, including the Japanese Earth Resources Satellite and NASA's Earth Observing System, promise to constrain thennal emissions from volcanoes more effectively than possible with existing orbital systems. These investigations will improve understanding of the physical processes that influence the emplacement of lavas, as well as the potential for detecting eruption precursors and evaluating volcanic hazards.
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Cuibus, Lucian <1982>. "Applications of infrared thermography in the food industry." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5559/1/Cuibus_Lucian_Tesi.pdf.
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In the last 20-30 years, the implementation of new technologies from the research centres to the food industry process was very fast. The infrared thermography is a tool used in many fields, including agriculture and food science technology, because of it's important qualities like non-destructive method, it is fast, it is accurate, it is repeatable and economical. Almost all the industrial food processors have to use the thermal process to obtain an optimal product respecting the quality and safety standards. The control of temperature of food products during the production, transportation, storage and sales is an essential process in the food industry network. This tool can minimize the human error during the control of heat operation, and reduce the costs with personal.
In this thesis the application of infrared thermography (IRT) was studies for different products that need a thermal process during the food processing. The background of thermography was presented, and also some of its applications in food industry, with the benefits and limits of applicability. The measurement of the temperature of the egg shell during the heat treatment in natural convection and with hot-air treatment was compared with the calculated temperatures obtained by a simplified finite element model made in the past. The complete process shown a good results between calculated and observed temperatures and we can say that this technique can be useful to control the heat treatments for decontamination of egg using the infrared thermography. Other important application of IRT was to determine the evolution of emissivity of potato raw during the freezing process and the control non-destructive control of this process. We can conclude that the IRT can represent a real option for the control of thermal process from the food industry, but more researches on various products are necessary.
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Cuibus, Lucian <1982>. "Applications of infrared thermography in the food industry." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5559/.
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In the last 20-30 years, the implementation of new technologies from the research centres to the food industry process was very fast. The infrared thermography is a tool used in many fields, including agriculture and food science technology, because of it's important qualities like non-destructive method, it is fast, it is accurate, it is repeatable and economical. Almost all the industrial food processors have to use the thermal process to obtain an optimal product respecting the quality and safety standards. The control of temperature of food products during the production, transportation, storage and sales is an essential process in the food industry network. This tool can minimize the human error during the control of heat operation, and reduce the costs with personal.
In this thesis the application of infrared thermography (IRT) was studies for different products that need a thermal process during the food processing. The background of thermography was presented, and also some of its applications in food industry, with the benefits and limits of applicability. The measurement of the temperature of the egg shell during the heat treatment in natural convection and with hot-air treatment was compared with the calculated temperatures obtained by a simplified finite element model made in the past. The complete process shown a good results between calculated and observed temperatures and we can say that this technique can be useful to control the heat treatments for decontamination of egg using the infrared thermography. Other important application of IRT was to determine the evolution of emissivity of potato raw during the freezing process and the control non-destructive control of this process. We can conclude that the IRT can represent a real option for the control of thermal process from the food industry, but more researches on various products are necessary.
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Ma, Shengli. "Mid-infrared and near-infrared vibrational circular dichroism new methodologies for biological and pharmaceutical applications /." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.
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Atkinson, Samantha D. M. "Applications of vibrational microspectroscopy." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368896.
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Urich, Artur. "Silica hollow core fibres for mid-infrared medical applications." Thesis, Heriot-Watt University, 2013. http://hdl.handle.net/10399/2946.
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In this thesis two types of silica hollow core microstructured fibres - the Negative Curvature Fibre and the Photonic Bandgap Fibre - are presented as a novel solution for the flexible delivery of Er:YAG laser radiation. The Negative Curvature Fibre and Photonic Bandgap Fibre had attenuations of 0.06 dB/m and 1.1 dB/m at 2.94 μm wavelength, respectively. This is an important wavelength regime for medical applications, specifically surgery, due to the existence of a strong absorption peak for water around 3 μm. The guidance of high energy pulses of the order of 195 mJ and 14.4 mJ respectively is demonstrated. These energies are sufficient to ablate soft and hard biological tissue. As verification, porcine bone was ablated in air and submerged in water to simulate practical application of a surgical device. The presented fibres are compared to alternative state-of-the-art solid and hollow core fibres, in respect of the fabrication, attenuation, pulse energy delivery capability, bend sensitivity and the output beam profile. The fabrication and characterisation of a novel sapphire endtip is also presented, which seals the hollow cores of the fibres from contamination and therefore increases the usability significantly. The endtip was shown to be mechanically robust, provide a hermetic seal and able to survive practical tissue ablation in air and water. These encapsulated fibres provide a new fully flexible delivery system for high energy Er:YAG laser radiation and hence will open up the possibility of new minimally invasive surgical procedures.
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Pramanik, Goutam [Verfasser]. "Near InfraRed (NIR) nanoemitters for bioimaging applications / Goutam Pramanik." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2014. http://d-nb.info/1049238583/34.
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Molavi, Behnam. "Near infrared spectroscopy : novel signal processing methods and applications." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45353.
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Oxygen is a critical component in living organisms and its concentration in tissue is an important parameter indicative of tissue metabolism, level of activity and health condition. As a result, measuring oxygen concentration in the tissue is essential in many clinical and research applications. Near Infrared Spectroscopy (NIRS)
is a non invasive method of measuring tissue oxygenation using diffusion of light in the tissue. NIRS as a safe, non invasive and low cost monitoring technology has been used in a wide range of applications including monitoring muscle and
brain oxygenation, brain computer interface and rehabilitation. The motivation for this thesis has been to develop new signal processing methods and to investigate potential new applications for NIRS.
One major characteristic of NIRS is its sensitivity to movement of the target tissue during the measurement. The effects of movements, known as motion artifacts, have limited clinical applications of NIRS in ambulant patients as well as experimental applications of NIRS monitoring in areas such as exercise science and sports medicine. In this thesis, we present a new method of reducing the effect of motion artifacts on NIRS signal using Discrete Wavelet Transform (DWT).
One of the areas of application which can significantly benefit from reduction of motion artifacts is NIRS-based wearable sensors. In particular, a potential and unexplored application of NIRS is providing a monitoring method for people with bladder control problems, which occurs in a variety of conditions including spinal cord injury and stroke. We investigate the application of NIRS for detection of bladder filling to capacity using a wearable wireless monitoring sensor which can
be used to warn the subject once the bladder content reaches a predefined percentage
of the full capacity. NIRS can be used as a functional neuroimaging method to identify brain activations during practice of a motor/cognitive task. One important question in this field is how the activated brain areas are interconnected. We thus investigate the use of phase information in NIRS channels to identify cortical connections and in particular, show the applicability of this approach in identifying language network
in human infants.
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Naji, Majid. "Applications of infrared waveguides and high-temperature storage units." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24438/24438.pdf.
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Sun, Jingye. "'Over the THz Horizon' : thermal infrared technologies and applications." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58865.
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Terahertz (THz) is loosely defined by the frequency range from 0.1 to 10 THz, and the 'over the THz horizon' thermal infrared from 10 to 100 THz is considered as an extension of the THz spectrum. This broad portion within the electromagnetic spectrum sees many applications due to its unique radiation characteristics. This thesis investigates the technologies and applications for the THz and the 'over the THz horizon' thermal infrared, and develops the proposed low cost thermal infrared 'THz Torch' spectrometer for material identification. In this thesis, the general background of the THz and extended THz spectrum, as well as the limiting factors for practical free-space THz applications and material characterizations from THz and infrared spectroscopy will be discussed in Chapter 1. State-of-the-art extended THz spectrum technologies, THz and infrared spectroscopy, atmospheric attenuations modelings and its applications will be reviewed in Chapter 2. In addition, the thermal infrared 'THz Torch' wireless secure communications system will also be reviewed. Chapter 3 will report on a research application-led study for predicting atmospheric attenuation, and tries to bridge the knowledge gap between applied engineering and atmospheric sciences. As a useful comparative baseline, Chapter 3 focuses specifically on atmospheric attenuation under pristine conditions, over the extended terahertz spectrum. Three well-known simulation software packages ('HITRAN on the Web', MODTRAN\textsuperscript{\textregistered}4 and LBLRTM) will be compared and contrasted. Techniques used for modelling atmospheric attenuation have been applied to investigate the resilience of (ultra-)wide fractional bandwidth applications to the effects of molecular absorption. Finally, with molecular emission included, carrier-to-noise ratio fade margins can be calculated for the effects of line broadening due to changes in macroscopic atmospheric conditions with sub-1 THz ultra-narrow fractional bandwidth applications. Outdoors can be far from pristine, with additional atmospheric contributions only briefly introduced here; further discussion is beyond the scope of this study, but relevant references have been cited. A comprehensive analytical review of methods for calculating the normalized power spectra, used to extract the effective complex dielectric properties of a sample will be undertaken in Chapter 4. Three generic power response models (zero-order, power propagation and electric field propagation) will be derived; these models act as a consolidated mathematical framework for the whole Chapter. With our unified engineering approach, the voltage-wave propagation, transmission line and telegrapher's equation transmission line models will be then independently derived; the first two giving the same mathematical solutions, while the third generates the same numerical results, as the exact electric field propagation model. Mathematically traceable simulation results from the various models will be compared and contrasted using an arbitrarily chosen dataset (window glass) from 1 to 100 THz. We will show how to extract the approximate effective complex dielectric properties using time-gated time-domain spectroscopy and also the exact values with our graphical techniques from the first-order reflectance and transmittance in Chapter 5. Our approach is then taken further by considering all the Fabry-Perot reflections with frequency- and space-domain spectroscopy. With scalar reflection-transmission mode infrared spectroscopy, the threshold conditions between the solution space that gives the single (exact) solution for the complex refractive index and that which gives multiple mathematical solutions will be modelled. By knowing threshold conditions, it is possible to gain a much deeper insight, in terms of sample constraints and metrology techniques that can be adopted, to determine the single solution. Finally, we propose a simple additional measurement/simulation step to resolve the ambiguity within the multiple solution space. Here, sample thickness is arbitrary and no initial guesses are required. The result from this work allows for the exact extraction of complex dielectric properties using simpler and lower cost scalar reflection-transmission mode spectroscopy. A thermal infrared spectrometer based on the 'THz Torch' concept will be introduced in Chapter 6. Both transmission and reflection modes of operation will be demonstrated within the extended THz range. Some preliminary experimental results, including the normalized power responses of common materials (e.g., fused silica), and paper and plastic banknotes will also be shown. In addition, a detailed power link budget analysis for the thermal infrared spectrometer will be discussed. Finally, several statistical techniques will be compared and contrasted to implement the material identification function of our spectrometer. The conclusions and further work relating to this thesis will be summarised in the last Chapter.
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Barker, Tom. "The military applications of near infrared spectroscopy in trauma." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6732/.
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This work examines tissue oxygenation (StO2), as measured by near infrared spectroscopy (NIRS), as tool for assessing trauma patients, with particular emphasis on its use in the deployed military environment. Resting StO2 values were examined and found to vary significantly between monitoring sites. Exercise was associated with a significant increase in StO2. Comparing the sensitivities of different NIRS monitoring sites in detecting simulated hypovolaemia, the forearm and deltoid were found be the most sensitive sites. The thenar eminence and brain were not sensitive to mild degrees of hypovolaemia. The administration of morphine was found to attenuate the StO2 response to hypovolaemia at all sites. In a porcine trauma model changes in StO2 recorded from both injured and uninjured muscle sites phase led those of base excess and lactate by 31–37 minutes, and demonstrate that injured monitoring sites can be used to accurately track patients’ response to resuscitation. In the deployed military setting NIRS was found to be a robust, easy to use technique for the initial assessment of patients. Although StO2 was not demonstrable superior to a combination of pulse rate and blood pressure it has several practical advantages that make it a useful adjunct to contemporary trauma care.
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Dershowitz, Adam L. (Adam Lee) 1967. "A passive infrared ice detection technique for helicopter applications." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/44271.
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Petrovich, Marco. "Gallium lanthanum sulphide glasses for near-infrared photonic applications." Thesis, University of Southampton, 2003. https://eprints.soton.ac.uk/15477/.
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This thesis investigates gallium lanthanum oxysulphide (GLS) glasses for potential fibre device applications. GLS glasses have low phonon energy and high rare earth solubility, which makes them candidates for rare earth-doped devices, and in particular for the 1.3 µm praseodymium-doped optical fibre amplifier. In addition, they have one of the highest nonlinear figures of merit among optical glasses, and therefore have potential for all-optical switching and other nonlinear devices. Practical applications, however, have been prevented by the impossibility, to date, of achieving single mode fibres with low attenuation. Previous efforts were concentrated on fabrication and especially tried to address the known issues of glass purity and thermal stability. The present work is focussed on assessing the fundamental glass transparency and on the mechanisms affecting the transmission loss of GLS glasses. The optical absorption at 1.55 and 1.7 µm was measured for the first time by laser absorption calorimetry using a tunable free electron laser source. To this end, a calorimeter was designed and commissioned and an improved model for the heat flow analysis of laser calorimetry was also developed. Our measurements identified optical absorption as the principal near-IR loss mechanism for GLS glasses. The extrinsic absorption due to transition metal ion impurities was also measured, and the presence of the weak absorption tail, due to absorption from gap states, was investigated. The occurrence of photoinduced effects and their impact on the material?s transmission wak also analysed. A thorough characterisation of the photodarkening and photoinduced absorption due to bandgap illumination, including its dependence on the excitation wavelength, and the kinetics of its formation, decay and reversibility, was achieved. Finally, the response of GLS glasses to high-intensity irradiation in the 1 µm wavelength region was studied and photoinduced darkening was observed to occur in low oxide undoped and Pr3+-doped GLS. All these topics are of great practical relevance. The present work clearly demonstrates that, in addition to the known fabrication challenges of monomode GLS fibres, careful consideration of the intrinsic transparency and photoinduced effects is essential for their successful application in fibre devices.
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Godenir, Aurelien. "Novel dilute nitride semiconductor materials for mid-infrared applications." Thesis, Lancaster University, 2008. http://eprints.lancs.ac.uk/54640/.
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A new approach to room temperature mid-infrared applications in the 3 -5 µm spectral range has been proposed through the development of novel dilute nitride materials. InAsN shows a large bandgap reduction with a small lattice mismatch when a small amount of nitrogen is introduced into the host InAs. Because the InAsN reported so far had generally poor crystalline quality and exhibited weak luminescence that quenched far below room temperature due to poorly understood localised states, the present thesis investigated the optimisation of the MBE growth of InAsN. The nitrogen incorporation was shown to be inversely dependent on the growth temperature, the growth rate and the arsenic flux, as was interpreted by a kinetic model. Luminescence from InAsN material showed two peaks, originating in bandgap-and localised state-related transitions. The emission related to the bandgap undergoes hardly any energy shift with increasing laser excitation power while it redshifts with increasing temperature. The emission from the localised states blueshifts with increasing laser excitation power and temperature. Rapid thermal annealing on InAsN layers improved the photoluminescence intensity and blueshifted the transition energy. InAsN was successfully grown with high crystalline quality. It showed strong photoluminescence which persisted up to room temperature with a reduced influence of the localised states and wavelength up to 4.5 µm was achieved when 2.5 % N were incorporated. An explanation of the temperature and nitrogen incorporation dependences of the InAsN bandgap was successfully proposed using Varshni's equation and an adapted band anticrossing model, where the nitrogen level energy is dependent on temperature and nitrogen composition. The crystalline quality and luminescence were both further improved by incorporating antimony into InAsN and strain balance in material for 4.2 µm applications was achieved with the novel InAsNSb alloy. A method to determine the composition of the quaternary was derived from bandgap models and lattice constant equation and the addition of antimony in InAsN was shown to enhance the nitrogen incorporation in InAsNSb. Finally, attempts at prototype InAsN and InAsNSb devices were reported, InAsNSb LEDs were demonstrated and electroluminescence from InAsNSb diodes at 3.88 µm at 4K was obtained.
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Duran, Joshua. "Silicon-Based Infrared Photodetectors for Low-Cost Imaging Applications." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton155653478017603.
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Liu, Qiankun. "SiGe photonic integrated circuits for mid-infrared sensing applications." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS166/document.
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La spectroscopie dans le moyen-infrarouge est une méthode universelle pour identifier les substances chimiques et biologiques, car la plupart des molécules ont leurs résonances de vibration et de rotation dans cette plage de longueurs d'onde. Les systèmes moyen infrarouge disponibles dans le commerce reposent sur des équipements volumineux et coûteux, tandis que de nombreux efforts sont maintenant consacrés à la réduction de leur taille et leur intégration sur circuits intégrés. L’utilisation de la technologie silicium pour la réalisation de circuits photoniques dans le moyen-infrarouge présente de nombreux avantages: fabrication fiable, à grand volume, et réalisation de circuits photoniques à hautes performances, compacts, légers et à faible consommation énergétique. Ces avantages sont particulièrement intéressant pour les systèmes de détection spectroscopique moyen infrarouge, qui besoin d'être portable et à faible coût. Parmi les différents matériaux disponibles en photonique silicium, les alliages silicium-germanium (SiGe) à forte concentration en Ge sont particulièrement intéressants en raison de la grande fenêtre de transparence du Ge, pouvant atteindre 15 µm. Dans ce contexte, l'objectif de cette thèse est d'étudier une nouvelle plate-forme SiGe à forte concentration en Ge, pour la démonstration de circuits photoniques moyen infra rouge. Cette nouvelle plate-forme devrait bénéficier d'une large gamme de transparence en longueurs d'onde de transparence et de la possibilité d’ajuster les propriétés des guides optiques (indice effectif, dispersion,…). Au cours de cette thèse, différentes plates-formes basées sur différents profils graduels du guide d’onde ont été étudiées. Tout d'abord, il a été démontré qu’il était possible d’obtenir des guides présentant de faibles pertes optiques inférieures à 3 dB/cm dans une large plage de longueurs d'onde, de 5,5 à 8,5 µm. Une preuve de concept de détection de molécules, basée sur l'absorption de la partie évanescent du mode optique a ensuite été démontrée. Ensuite, les composants formant les briques de base classiques de la photonique intégrée ont été étudiés. Les premières cavités intégrées ont été réalisées à 8 µm. Deux configurations ont été étudiées : des cavité Fabry-Perot utilisant des miroirs de Bragg intégrés dans les guides d’onde et des résonateurs en anneau. Un spectromètre à transformée de Fourier fonctionnant sur une large bande spectrale, et pour les deux polarisations de la lumière a également été démontré. Tous ces résultats reposent sur la conception des matériaux et des composants, la fabrication en salle blanche et la caractérisation expérimentale. Ce travail a été effectué dans le cadre du projet européen INsPIRE en collaboration avec le Pr. Giovanni Isella de Politecnico Di MilanoMid-infrared (mid-IR) spectroscopy is a nearly universal way to identify chemical and biological substances, as most of the molecules have their vibrational and rotational resonances in the mid-IR wavelength range. Commercially available mid-IR systems are based on bulky and expensive equipment, while lots of efforts are now devoted to the reduction of their size down to chip-scale dimensions. The use of silicon photonics for the demonstration of mid-IR photonic circuits will benefit from reliable and high-volume fabrication to offer high performance, low cost, compact, lightweight and power consumption photonic circuits, which is particularly interesting for mid-IR spectroscopic sensing systems that need to be portable and low cost. Among the different materials available in silicon photonics, Germanium (Ge) and Silicon-Germanium (SiGe) alloys with a high Ge concentration are particularly interesting because of the wide transparency window of Ge up to 15 µm. In this context, the objective of this thesis is to investigate a new Ge-rich graded SiGe platform for mid-IR photonic circuits. Such new plateform was expected to benefit from a wide transparency wavelength range and a high versatility in terms of optical engineering (effective index, dispersion, …). During this thesis, different waveguides platforms based on different graded profiles have been investigated. First it has been shown that waveguides with low optical losses of less than 3 dB/cm can be obtained in a wide wavelength range, from 5.5 to 8.5 µm. A proof of concept of sensing based on the absorption of the evanescent component of the optical mode has then been demonstrated. Finally, elementary building blocs have been investigated. The first Bragg mirror-based Fabry Perot cavities and racetrack resonators have been demonstrated around 8 µm wavelength. A broadband dual-polarization MIR integrated spatial heterodyne Fourier-Transform spectrometer has also been obtained. All these results rely on material and device design, clean-room fabrication and experimental characterization. This work was done in the Framework of EU project INsPIRE in collaboration with Pr. Giovanni Isella from Politecnico Di Milano
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BOBBA, SERENA. "Near-Infrared Spectroscopy for Freeze-Drying: Applications for Pharmaceuticals." Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2957736.
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Ndebeka, Wilfrid Innocent. "Characterization of thulium doped fiber for mid infrared laser applications." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6606.
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Goldberg, Mitchell David. "The generation and applications of a spectrally resolved infrared radiance climatology derived from the atmospheric infrared sounder." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9231.
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Thesis (Ph.D.) -- University of Maryland, College Park, 2009.Thesis research directed by: Dept. of Atmospheric and Oceanic Science. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Park, Benjamin Alan. "Inductively coupled plasma induced type conversion of HgCdTe for infrared photodiode applications." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0003.
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[Truncated abstract] Infrared (IR) detectors have many applications across a wide range of industries. HgCdTe is the leading semiconductor material for fabrication of high-performance IR detectors due to a number of superior fundamental material properties. However, significant technological challenges are involved in working with this narrow bandgap material, primarily due to its low damage threshold. Exposure of HgCdTe to H2/CH4/Ar plasma in IR detector fabrication processes is known to generally cause modifications to the electrical properties of the material, specifically including p-to-n type conductivity conversion. This is an undesirable side-effect when aiming to perform physical etching for device delineation. However, it has previously been exploited as a novel means of planar n-on-p junction formation for high-performance HgCdTe photodiode fabrication. This technique offers significant advantages over established junction formation techniques such as ion implantation and ion beam milling. These include not requiring a postimplant anneal to activate dopants and repair ion-induced damage, and not necessitating reapplication of the passivation layer after junction formation. Previous work has demonstrated high-performance photodiodes based on H2/CH4 plasmainduced junction formation using a parallel-plate reactive ion etching (RIE) tool. The newer hybrid inductively coupled plasma (ICP) RIE technology is capable of greater control of the plasma condition, and therefore potentially greater control of the plasma-induced type conversion process. ... Differential profiling has been performed using wet chemical etch-backs between measurements to investigate the depth profiles of the carrier species. This investigation has revealed that the ICPRIE-induced type conversion depth is most sensitive to the sample temperature during exposure. The other ICPRIE process parameters, including the process pressure, RIE power, and ICP power, have also been shown to affect the type conversion depth and the electron concentration and mobility in the type converted layer. Based on this carrier transport characterisation work, a set of ICPRIE process conditions was identified as being suitable for formation of n-on-p junctions for high-performance photodiode fabrication. Three sets of photodiodes have been fabricated and characterised. The ICPRIE process parameters for junction formation were refined based on the parametric study of the carrier transport properties. The performance of photodiodes from each sample was measured to improve with each set of variations to the conditions for ICPRIE-induced junction formation, based on performance characterisation by current-voltage and noise measurements. Dynamic resistance area products up to 2.5 × 106 O.cm2 at 77K were measured for these mid-wave (MW) IR photodiodes (cutoff wavelength 5.3 µm), which is equivalent to the best reported results in the literature for devices based on established fabrication techniques. Gated photodiode structures were used to demonstrate that surface passivation is the performance-limiting factor for these photodiodes. This indicates not only that the set of ICPRIE conditions developed in this work to date is suitable for producing high-performance photodiodes, but that there is also potential for further improvement.
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Johnson, Jennifer Erin. "Remote sensing applications of uncooled long-wave infrared thermal imagers." Thesis, Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/johnson/JohnsonJ0812.pdf.
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The commercial development of microbolometer uncooled long-wave thermal infrared imagers in conjuncture with advanced radiometric calibration methods developed at Montana State University has led to new uses of thermal imagery in remote sensing applications. As a result of being uncooled, microbolometer imagers are notably lighter and cheaper than typical cooled imagers, making them ideal for remote sensing. Two novel uses are discussed in the work presented here. The first is the imaging of beehives in order to remotely determine the hive vitality. Bees thermally regulate their hives to a narrow range of temperatures that creates a thermal signature seen in thermal infrared images. For each of the hives imaged, frame counts (or the number of full frames of bees in each hive) were found by manual inspection. Linear regressions of the normalized frame counts of the hives were performed versus the measured hive thermal radiance values. The resulting plots showed a strong relationship between the normalized frame count and the mean radiance of each hive, particularly in images taken just prior to dawn. The second novel use was imaging vegetation exposed to large ground concentrations of CO ����� over a four-week period in summer for use in leak detection. A CO ����� leak was simulated in a test field run by the Zero Emissions Research and Technology Center. Thermal infrared images were acquired along with visible and near-infrared reflectance images of the exposed vegetation and healthy control vegetation. Thermal radiance statistics were measured and a regression was performed versus the day of the experiment. The infrared data were found to have a strong R ² value and clearly show the effect of the CO ����� on the vegetation. An additional regression was run on the infrared data combined with the reflectance data, and this was found to not add any unique information to the vegetation reflectance data. Both methods were found to independently indicate the potential of a CO ����� leak before it was detected visually.
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Golby, J. A. "Applications of carbon dioxide lasers in high resolution infrared spectroscopy." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373667.
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Austin, David. "Studies of plasmonics and metamaterials for mid-infrared device applications." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522577.
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Breivik, Magnus. "Fabrication of mid-infrared laser diodes : for gas sensing applications." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23859.
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Mid-infrared laser diodes have been fabricated and tested, and semiconductor materials related to mid-infrared lasers have been characterized by X-ray diffraction (XRD). The temperature dependent lattice constant of Al0.9 Ga0.1AsySb1−y, GaSb, AlSb and InSb have been examined using XRD measurements. For Al0.9Ga0.1AsySb1−y, GaSb and AlSb, the lattice constants were measured for temperatures up to 546°C, while for InSb it was examined up to 325°C. For AlSb, also the temperature dependent Poisson ratio was determined. It was found that the thermal expansion of Al-containing layers above room temperature was higher than previously reported. An expression for the lattice matching condition for Al0.9Ga0.1AsySb1−y epilayers on GaSb substrates as a function of temperature was presented. For GaSb, it was found that the work of Bublik et al. [1] provided accurate data for the temperature dependent lattice constant, and either our data or Bublik et al. [1]’s data should be used. The measurement technique was validated by measuring the lattice constants of Si and GaAs, where our measured values were found to be in agreement with previously published values. For AlSb it was found that the thermal expansion was larger than previously reported in the literature. For InSb it was found that the lattice constant near room temperature was larger than previously reported, and the thermal expansion above 100°C was larger than previously reported. Laser material was grown using molecular beam epitaxy (MBE). The grown samples were processed into Y-junction laser diodes. The lasers were etched using inductively coupled plasma reactive ion etching (ICP-RIE) and photoresist (PR) ma-N 440 was spun on and baked for use as electrical insulation. The insulation layer was etched using reactive ion etching (RIE) to uncover the top of the etched lasers for contacting. It was found that a O2/CF4 etch gave the best uniformity of the insulation layer. The lasers were contacted and tested. The Y-junction lasers were characterized using power measurements for optical power, multimeters for diode voltage, Fourier transform infrared (FTIR) for spectral measurements, and an infrared camera for near and far field measurements. The measurements suggested that the curved waveguide did not guide the light, most likely due to a low refractive index contrast. This was later supported by scanning electron microscope (SEM) measurements, which showed an etch depth of 1.4 μm, much lower than the etch target of 1.9 μm. The Y-junction waveguides were simulated using the beam propagation method (BPM). Based on 2D BPM simulations, it was found that an effective refractive index contrast of at least 0.03 is required for guiding light in a curved waveguide for our dimensions, and that waveguide roughness due to processing is less important. The simulations support the findings from the laser measurements, and further suggest that a deeper etch is required for functioning Y-junction laser diodes. Suggestions for improvements to the manufacturing mid-infrared laser diodes are presented.
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GoluboviÄ, Boris 1967. "Study of near-infrared pumped solid-sate lasers and applications." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10046.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (leaves 114-121).
by Boris Golubovic.
Ph.D.
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Cheng, Hok Yan. "Near infrared fluorescence probes : towards applications in fluorescence guided surgery." Thesis, University of Hull, 2017. http://hydra.hull.ac.uk/resources/hull:16529.
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Surgery has been a popular method for the treatment of cancers, in particular solid tumours; but the surgical margins for cancerous tissues are often indistinct and in most cases, the poor identification of residual cancer tissues can result in re-excision. Therefore, near infrared (NIR) fluorescence-guided surgery (FGS) is being developed as a real time intra-operative imaging technique to assist surgeons by improving the accuracy and precision of the removal of tumours. However, current FDA approved fluorophores suffer from poor chemical stability, limited water-solubility, and lack selectivity toward neoplastic tissue, limiting their clinical application. These current challenges have led to the development of new and improved fluorophores capable of absorbing and emitting light at NIR wavelengths, negating autofluorescence and improving deeper light transmission. Throughout this project, a series of BODIPYs, aza-BODIPYs and bacteriochlorins were synthesised and developed for bioimaging applications. Despite many of them showing interesting fluorescence properties, the investigation suggested aza-BODIPYs were the most promising red / NIR fluorophores (λem 600-700 nm) due to their excellent photostability. Methods have been developed to incorporate functionalities suitable for bioconjugation. Different bioconjugation strategies have been explored to covalently conjugate the NIR fluorophores to a clinically relevant protein, peptide and antibody under mild conditions. The viability of aza-BODIPY conjugates against biological targets were investigated and a range of other novel targeted NIR fluorophores were successfully developed. In vitro fluorescence imaging was subsequently carried out to demonstrate the enhanced selectivity of the targeting NIR fluorophores toward overexpressed receptors on various cancer cells lines. This project has demonstrated the potential of aza-BODIPY in biological imaging and developed targeted NIR fluorophores. Further biological evaluation is progressing with the eventual aim of developing a pre-clinical model for NIR FGS in oncology.
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Adonis, Marco Leroy. "An investigation and design of an infrared radiation heat profile controller." Thesis, Peninsula Technikon, 2002. http://hdl.handle.net/20.500.11838/1158.
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Thesis (MTech (Electrical Engineering))--Peninsula Technikon, 2002This research outlines the development and design of an infrared radiation heating profile controller. The study includes both the theoretical aspects of the design process as well as giving an overview of the practical facets involved. The controller was subjected to comparative testing with a proportional control model, in order to observe its performance and validate its effectiveness. A need exists for these types of controllers and proved to be the motivation to embark on this investigation. Controllers of this nature that are commercially available either lacks the functionality of this unit or are too expensive to implement for research purposes. This unit was designed with cost effectiveness in mind but still meet the standards required of an industrial style controller. To this end the construction was completed using low cost and affordable electronic components. Heating profiles are necessary and useful tools for the proper processing of a host of materials. The controller developed in this research is able to within a fair degree of accuracy track a heating profile. The results confirm that this programmable control model to be a benefit and a valuable tool in temperature regulation. This means that intensive studies into the effects of infrared radiation on materials are now feasible. Research of this nature could possibly expand the application of infrared as a heating mechanism. Although tests were conducted on this controller, they are not meant to serve as an exhaustive analysis. The conclusions of these examinations do reveal the benefit of such a controller. More rigorous investigation is suggested as a subject for further study.
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Aning, Jonathan. "Critique of fourier transform infrared microspectroscopy applications to prostate pathology diagnosis." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/5626.
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Prostate cancer is a biologically heterogenous disease with considerable variation in
clinical aggressiveness. Gleason grade, the universally accepted method for
classification of prostate cancer, is subjective and gives limited predictive information
regarding prostate cancer progression. There is a clinical need for an objective, reliable
tool to help pathologists improve current prostate tissue analysis methods and better
assess the malignant potential of prostate tumours. Fourier Transform Infrared (FTIR)
microspectroscopy is a powerful bioanalytical technique that uses infrared light to
interrogate biological tissue. The studies detailed in this thesis examine the ability of
FTIR combined with multivariate analysis to discriminate between benign,
premalignant and malignant prostate pathology in snap frozen, paraffinated and
deparaffinated tissue.
Prostate tissue was collected during and after urological procedures performed between
2005 and 2008. The tissue was analysed utilising a bench top FTIR system in point and
image mapping modes. The histology under interrogation was identified by a uro-
pathologist. Multivariate analysis was applied to the spectral dataset obtained. FTIR
performance was evaluated.
FTIR was able to reproducibly discriminate between benign and malignant prostate
tissue in a pilot study. Cross validated diagnostic algorithms, constructed from the
spectral dataset in this experiment, achieved sensitivities and specificities of 95% and
89% respectively.
FTIR analysis of transverse paraffinated and deparaffinated radical prostatectomy
sections achieved good differentiation of the benign, premalignant and malignant
pathology groups. However the performance of diagnostic algorithms constructed from
this dataset under cross validation was poor.
The work in this thesis illustrates the potential of FTIR to provide an objective method
to assist the pathologist in the assessment of prostate samples. The limitations of the
technique and directions for future work are presented.
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Erickson, Brice Carl. "Multicomponent flow injection analysis and quantitative infrared emission spectroscopy : chemometric applications /." Thesis, Connect to this title online; UW restricted, 1988. http://hdl.handle.net/1773/8633.
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Panthani, Matthew George. "Colloidal Nanocrystals with Near-infrared Optical Properties| Synthesis, Characterization, and Applications." Thesis, The University of Texas at Austin, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3572875.
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Colloidal nanocrystals with optical properties in the near-infrared (NIR) are of interest for many applications such as photovoltaic (PV) energy conversion, bioimaging, and therapeutics. For PVs and other electronic devices, challenges in using colloidal nanomaterials often deal with the surfaces. Because of the high surface-to-volume ratio of small nanocrystals, surfaces and interfaces play an enhanced role in the properties of nanocrystal films and devices.
Organic ligand-capped CuInSe2 (CIS) and Cu(InXGa 1-X)Se2 (CIGS) nanocrystals were synthesized and used as the absorber layer in prototype solar cells. By fabricating devices from spray-coated CuInSe nanocrystals under ambient conditions, solar-to-electric power conversion efficiencies as high as 3.1% were achieved. Many treatments of the nanocrystal films were explored. Although some treatments increased the conductivity of the nanocrystal films, the best devices were from untreated CIS films. By modifying the reaction chemistry, quantum-confined CuInSe XS2-X (CISS) nanocrystals were produced. The potential of the CISS nanocrystals for targeted bioimaging was demonstrated via oral delivery to mice and imaging of nanocrystal fluorescence.
The size-dependent photoluminescence of Si nanocrystals was measured. Si nanocrystals supported on graphene were characterized by conventional transmission electron microscopy and spherical aberration (Cs)-corrected scanning transmission electron microscopy (STEM). Enhanced imaging contrast and resolution was achieved by using Cs-corrected STEM with a graphene support. In addition, clear imaging of defects and the organic-inorganic interface was enabled by utilizing this technique.
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Tan, Rendy Howe Choong. "Synthesis and characterisation of perfluorinated ianthanide complexes for near-infrared applications." Thesis, Queen Mary, University of London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522325.
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Khan, Saeed. "Silicon photonic devices for optical delay lines and mid infrared applications." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5961.
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Silicon photonics has been a rapidly growing subfield of integrated optics and optoelectronic in the last decade and is currently considered a mature technology. The main thrust behind the growth is its compatibility with the mature and low-cost microelectronic integrated circuits fabrication process. In recent years, several active and passive photonic devices and circuits have been demonstrated on silicon.
Optical delay lines are among important silicon photonic devices, which are essential for a variety of photonic system applications including optical beam-forming for controlling phased-array antennas, optical communication and networking systems and optical coherence tomography. In this thesis, several types of delay lines based on apodized grating waveguides are proposed and demonstrated. Simulation and experimental results suggest that these novel devices can provide high optical delay and tunability at very high bit rate.
While most of silicon photonics research has focused in the near-infrared wavelengths, extending the operating wavelength range of the technology into in the 3–5 &"181;m, or the mid-wave infrared regime, is a more recent field of research. A key challenge has been that the standard silicon-on-insulator waveguides are not suitable for the mid-infrared, since the material loss of the buried oxide layer becomes substantially high. Here, the silicon-on-sapphire waveguide technology, which can extend silicon's operating wavelength range up to 4.4 &"181;m, is investigated. Furthermore, silicon-on-nitride waveguides, boasting a wide transparent range of 1.2–6.7 ?m, are demonstrated and characterized for the first time at both mid-infrared (3.39 ?m) and near-infrared (1.55 ?m) wavelengths.Ph.D.
Doctorate
Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
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Buyuksalih, Gurcan. "Geometric and radiometric calibration of video infrared imagers for photogrammetric applications." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284703.
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Petty, Christopher J. "The development and applications of near infrared Fourier transform Raman spectroscopy." Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315498.
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Bain, James R. P. "Near infrared tunable diode laser spectroscopy for aero engine related applications." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=17982.
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Tunable diode laser spectroscopy is a widely used technique for recovering quantitative gas information in a range of industrial applications. Established methods often use readily available, robust and low cost optoelectronic hardware in the near-infrared, with output wavelengths that coincide with the absorption spectra of several important gas species of interest, providing a versatile platform for gas analysis instrumentation. In this work the challenges associated with the recovery of gas information from harsh detection environments, particularly for aero engine diagnostics, are considered. For stand-alone instrumentation, calibration-free direct absorption measurements are highly advantageous yet calibrated techniques employing wavelength modulation spectroscopy are often favoured due to their significantly higher sensitivities. Recent developments have enabled calibration-free line shape recovery using lock-in amplifier detection of the residual amplitude modulat ion in wavelength modulated signals. These techniques have significant potential in harsh environments, but the overall sensitivity is limited by distortions to the recovered line shapes at high modulation amplitudes and by large background signals that saturate the detection electronics. In this thesis, solutions to these two problems are proposed, investigated and validated. A correction function is derived that is able to account for line shape distortions at arbitrarily high modulation indices. Application of the function depends upon knowledge of the experimental modulation index and two methods for extracting this information directly from the experimental signals are described. The full correction procedure has been experimentally validated. An investigation was made into the use of autobalanced photoreceivers, typically used for common mode noise cancellation, for direct absorption measurements and in a different configuration for nulling of the residual amplitude modulation (RAM) in wavelength modulation spectroscopy. In addition an external amplitude modulator has been iv shown to be an effective method for producing sensitive absorption signals that are free of distortions, recoverable at frequencies that are outside the bandwidth of most environmental noise sources. A temperature sensor based on ratio thermometry of ambient water vapour absorption was designed and evaluated. The sensor is intended to provide accurate intake gas temperature information during aero engine ground testing when misting conditions prevent standard thermocouples from providing reliable data. Direct detection and second harmonic wavelength modulation spectroscopy experiments were undertaken in an environmental chamber, over the range 273-313K, to test the potential accuracy of the proposed system. Using a second harmonic peak height method, temperature information based on a calibration was able to recover temperature measurements with precision of ±0.4K however the overall accuracy suffered from a problematic calibration drift. Three engine test campaigns are described in which a range of recovery methods and potential optical system layouts are evaluated for the purposes of intake and exhaust mounted test bed sensor systems. The effects of extreme noise conditions were observed on a variety of measurements and favourable detection and modulation options were identified for the purpose of planning proposed future engine tests. Exhaust plume measurements of high temperature water vapour on the Rolls-Royce Environmentally Friendly Engine demonstrator established the viability of temperature and concentration measurements up to 850K.
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Pang, Jing Sheng. "Engineered nanostructures for metal enhanced fluorescence applications in the near-infrared." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/43157.
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Recent advancements in fabrication techniques allow construction of nanostructures with well-defined features in nanometres scale. Tiny nanostructures that have features below the resolution of optical diffraction limit can now be made in the laboratory. The specific properties of those nanostructures with specific properties made from variety of materials allow us to study and explore many different properties that have never been observed while they are in bulk. One such phenomenon is localised surface plasmon resonance effect, which is exhibited by certain materials when in nanometric size. Their peculiar interaction with light is in such a way that the optical properties such as reflection and transmission deviate from typical characteristics and change according to the material involved and their shapes. Furthermore, this effect could also enhance the electric field in a specific area of the structure. This thesis is motivated by the attractiveness of the tunability of localised surface plasmon resonance and aims at exploring those properties by fabricating multiple types of nanostructures through a low-cost and versatile technique called nanosphere lithography. By improving the technique and combining with other fabrication techniques (such as oxygen plasma etching and argon ion milling), a large variety of nanostructures with hexagonal lattice like as nanocones, nanopencils, and nanofins arrays have been successfully created. Among them, three main types of nanostructure were selected for detailed study: nanotriangle, nanodisc, and nanohole-disc arrays. The distance between the adjacent nanoparticles were changed in those structures and strong interparticle coupling behaviours were observed as the distance between them becomes shorter. Current portable biosensing devices for in vitro studies are limited by the sensitivity limit of the detector, the poor quality of emitters and the size of the devices. In this thesis, the application of localised surface plasmon resonance for near infrared in vitro biosensing is explored. This is achieved through a mechanism called metal enhanced fluorescence. The techniques take advantage of the high electrical field strength and the resonance condition of the plasmon to enable a fluorophore to achieve brighter emission. The greater the resonance and electrical field are, the greater the emission amplification would be. Such effect makes it highly attractive for near infrared in vitro studies, which benefits from high optical penetration of common biology components such as water and lipids, but suffer from poor emission of existing fluorophores. Thus, enhancement of the emission signals through metal enhance fluorescence mechanism is an attractive route to obtain better signal to noise ratio in medical diagnostic, and improve detectability while at the same time reduce the need of a high sensitivity detector which can be costly and large in size. The three chosen nanostructures, i.e. nanotriangular arrays, nanodisc arrays and nanohole-disc arrays have shown marked enhancement in the emission of attached fluorophores up to 83x, 235x, and 411x respectively, making them highly attractive nanostructures for such application.
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Gambaryan, K. M., V. G. Harutyunyan, V. M. Aroutiounian, T. Boeck, O. Marquardt, and F. Schuette. "InAsSbP-based Quantum Dot Mid-Infrared Photodetectors: Fabrication, Properties and Applications." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35354.
Full textAbstract:
The mid-infrared photoconductive cells (PCC) made of n-InAs(100) crystals with InAsSbP quantum dots (QDs) on the PCC surface, as well as InAsSbP-based diode heterostructures with QDs on epilayer–substrate interface are reported. Both QDs-based semiconductor structures are considered as attractive devices for several mid-infrared applications. The liquid phase epitaxy, AFM, TEM and STM techniques are utilized for the growth of QDs and epitaxial cap layers and their characterization, respectively. Anoma-lous photovoltaic effect is detected in PCC with type-II QDs. The open-circuit voltage and short-circuit cur-rent are measured versus radiation power density of the He-Ne laser at λ 3.39, 1.15 and 0.63 μm wave-lengths. The formation of QDs leads to the increasing of the PCC’s sheet resistance up to one order and re-sults in red shift of the photoresponse spectrum. The QDs-based PCC’s voltage and current responsivity at room temperature are equal to 1.5 V/W and 82 mA/W, respectively, at zero bias and λ 3.39 μm. The main peak at 3.48 μm and additional peaks at 2.6 μm and 2.85 μm wavelengths revealed on QDs-based devices’ photoresponse and luminescence spectra allow to fabricate optical gas sensors, in particularly, for the me-thane, water vapor and carbon dioxide detection.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35354
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Durairaj, Revathy. "Langmuir-Schaefer films of a ferroelectric copolymer for infrared imaging applications." Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1334185809.
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