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Relevant bibliographies by topics / Refractive index variation

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Academic literature on the topic 'Refractive index variation'

Author: Grafiati

Published: 25 May 2024

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Journal articles on the topic "Refractive index variation"

1

Paroha, P. P. "Variation in refractive index of sugar solution with concentration using Newton’s rings." YMER Digital 21, no. 06 (June 29, 2022): 1129–32. http://dx.doi.org/10.37896/ymer21.06/a8.

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Refractive index or index of refraction is an important physiochemical property of an optical medium. Here we report its value for sugar solution of various concentrations (0%, 5%, 10% and 20%) using the Newton’s rings set up for yellow light from sodium lamp (λ=5893Å). Newton’s Rings are an interference pattern generated via division of amplitude principle. The set-up used in our study is easily available in an undergraduate laboratory. The study correctly presents effect of increasing number of particles in a liquid on its refractive index. KEY WORD: Newton’s Rings, refractive index, interference and sugar solution.

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Twu, Ruey-Ching, and Chia-Wei Hsueh. "Phase interrogation birefringent-refraction sensor for refractive index variation measurements." Sensors and Actuators A: Physical 253 (January 2017): 85–90. http://dx.doi.org/10.1016/j.sna.2016.11.029.

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Sediq, Khalid N., Fahmi F. Muhammadsharif, Simko O. Ramadan, and Shalaw Z. Sedeeq. "Design and Study of a Nanocavity-based One-dimensional Photonic Crystal for Potential Applications in Refractive Index Sensing." ARO-THE SCIENTIFIC JOURNAL OF KOYA UNIVERSITY 11, no. 2 (October 9, 2023): 95–98. http://dx.doi.org/10.14500/aro.11298.

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Refractive index (RI) can be used to identify a particular substance and determine its purity and concentration. The RI of glucose solution with various concentrations can be determined using a distributed Bragg reflective (DBR) device containing a nanocavity. The optical property of the reflection spectrum produced by DBR is sensitive to the variation of the refractive index. In this study, a DBR with a cavity width of 220 nm, located in the middle of the device, is designed and used to sense the variation in the refractive index of glucose at different concentrations. The proposed design showed a sharp dip pattern within the reflection spectrum. The wavelength of the absorption peak was found to be sensitive to trivial variations in the refractive index of glucose solution. Results showed that the variation in the refractive index of glucose within the order of Δn = 0.02 has led to a noticeable shift in the absorption spectrum by Δλ = 2.6 nm. Furthermore, the sensitivity of the proposed device was found to be 130 nm/RIU which is considered high compared with those reported in the literature. Hence, the proposed structure can be a promising optical device for chemical ultrasensing applications.

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Kim, Young L., Joseph T. Walsh, Thomas K. Goldstick, and Matthew R. Glucksberg. "Variation of corneal refractive index with hydration." Physics in Medicine and Biology 49, no. 5 (February 13, 2004): 859–68. http://dx.doi.org/10.1088/0031-9155/49/5/015.

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5

Singh, Nageshwar. "Spectral Intensity Variation by the Correlation Function of Refractive Index Fluctuations of the Liquid Medium." International Journal of Optics 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/525142.

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It is proposed that a macroscopic theory of propagation and scattering of light through random media can be functional for the dye liquid flowing media in the microscopic levels too, with modest approximations. Maxwell’s equation for a random refractive index medium is approximated and solved for the electric field. An analytical expression for the spectral intensity of the field scattered by the refractive index fluctuations inside a medium has been derived which was valid within the first Born approximation. Far field spectral intensity variation of the radiation propagating through the liquid medium is a consequence of variation in correlation function of the refractive index inhomogeneities. The strength of radiation scattered in a particular direction depends on the spatial correlation function of the refractive index fluctuations of the medium. An attempt is made to explain some of the experimentally observed spectral intensity variations, particularly dye emission propagation through liquid flowing medium, in the presence of thermal and flow field.

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RUOFF, ARTHUR L., and KOUROS GHANDEHARI. "THE REFRACTIVE INDEX AT THE CENTER OF THE SURFACE OF PRESSURIZED DIAMOND ANVIL TIPS." Modern Physics Letters B 07, no. 15 (June 30, 1993): 1039–43. http://dx.doi.org/10.1142/s021798499300103x.

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An expression for the variation of the refractive index of diamond with density is determined. This is used to show consistency between Brillouin scattering results obtained at atmospheric pressure and more recent direct measurements of the refractive index under hydrostatic pressure to 40 GPa. The stress distribution at the diamond anvil tip is then computed and the variation of the refractive index at the tip of the anvil is obtained. The refractive index at the tip is a slowly decreasing function of the sample pressure.

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RUOFF, ARTHUR L., and KOUROS GHANDEHARI. "THE REFRACTIVE INDEX OF HYDROGEN AS A FUNCTION OF PRESSURE." Modern Physics Letters B 07, no. 13n14 (June 20, 1993): 907–11. http://dx.doi.org/10.1142/s0217984993000904.

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It is shown that the refractive index of hydrogen is given by n H 2 = 1 + 3.046 ρ + 2.6 ρ2 where ρ has units of mol/cm3. Here ρ at a given pressure, P, can be obtained from the equation of state, ρ(P). This relation is combined with that for the refractive index of loaded diamond anvils to obtain n H 2/n D vs P. This is found to be in good agreement with the ratio n H 2/nD measured directly at different pressures by Fabry-Perot interferometry. The density variation of the molar refraction is computed.

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Naoi, Yusaku. "Sensor for refractive index variation of an optical surface using a high-refractive-index waveguide." Optical Engineering 46, no. 10 (October 1, 2007): 104601. http://dx.doi.org/10.1117/1.2799182.

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Szekeres, A., K. Christova, and A. Paneva. "Stress-induced refractive index variation in dry SiO2." Philosophical Magazine B 65, no. 5 (May 1992): 961–66. http://dx.doi.org/10.1080/13642819208217913.

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10

Lagomarsino, S., P. Olivero, S. Calusi, D. Gatto Monticone, L. Giuntini, M. Massi, S. Sciortino, A. Sytchkova, A. Sordini, and M. Vannoni. "Complex refractive index variation in proton-damaged diamond." Optics Express 20, no. 17 (August 9, 2012): 19382. http://dx.doi.org/10.1364/oe.20.019382.

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Dissertations / Theses on the topic "Refractive index variation"

1

Stephenson, David. "Modeling variation in the refractive index of optical glasses /." Online version of thesis, 1990. http://hdl.handle.net/1850/10952.

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Stein, Benedikt. "Plasmonic devices for surface optics and refractive index sensing." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00849967.

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In this thesis devices for controlling the flow of surface plasmon polaritons are described. Dielectric and metallic nanostructures were designed for this purpose, and characterized by leakage radiation microscopy in real and in reciprocal spaces. Manipulation of surface plasmons by dielectric lenses and gradient index elements is presented, and negative refraction, steering and self-collimation of surface plasmons in one- and two-dimensional plasmonic crystals is demonstrated. The achieved degree of control was applied for routing of nanoparticles by optical forces, as well as for two methods of enhancing the figures of merit of plasmonic refractive index sensors, based on the one hand on Fano resonances natural to leakage radiation microscopy, and on the other hand on anisotropie plasmonic bandstructures.

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De, Freitas Jolyon Mark O. "Interferometric characterisation of refractive index variations in vitreous silica." Thesis, University of Aberdeen, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387257.

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The motivation for the measurement of refractive index variations in vitreous silica comes from the NASA/Stanford University Gravity Probe-B experiment. This experiment proposes to measure directly some of the predictions of the General Theory of Relativity by observing the extent of precession of a gyroscope in orbit around the Earth. The rotor of the proposed gyroscope will be made of vitreous silica. Screening requirements for the homogeneity of the silica rotor have been indicated in terms of the sensitivity of the mass density distribution measurements as Δp/p = 3 x 10^-7 (or equivalently, refractive index sensitivity Δn = 1 x 10 ^-7), with a spatial resolution (to allow control of low order multi-pole moments) to better than 5mm. The thrust of the thesis is towards improvement of existing instrumentation, actual screening of samples, and spectral characterisation of the samples in the spatial frequency domain. After a brief introduction to the instrumentation, a complete matrix analysis of the plane mirror heterodyne interferometer was then developed, using the coherency matrix representation. A detailed analysis of periodic errors (non-linearity) associated with high precision polarisation heterodyne interferometry was carried out. A worst case peak-to-peak nonlinearity of 6.2nm was calculated for the single pass plane mirror heterodyne system. A simple analogue phase meter was then designed and built; its use resulted in an increase of over an order of magnitude in the resolution of the interferometer from λ/300 (2.2nm) to λ/4000 (0.16nm). High precision measurements of refractive index variations in vitreous silica are also reported for the first time. Measurements are repeatable to the Δn = 10^-7 level, with phase meter errors of ±0.7% (i.e. 10^-8 sensitivity).

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Au, L. B. "Wave propagation and grating formation in photorefractive materials." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235016.

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Modaresialam-Bochet, Mehrnaz. "Fabrication of dielectric nanostructures by nano imprint lithography and sol-gel chemistry for optical applications." Electronic Thesis or Diss., Aix-Marseille, 2021. http://www.theses.fr/2021AIXM0345.

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Le but de cette thèse est de développer des méthodes d’élaboration de métasurfaces nanostructurées par combinaison de la chimie sol-gel et de la lithographie par nano impression (soft-NIL). Celle-ci présente notamment des intérêts d’ordres scientifiques et technologiques. En outre, elle entre dans la tendance générale du développement des processus rapide à faibles coûts utilisant des matériaux biocompatibles et non toxiques. Dans un premier temps, nous présenterons l'élaboration de nouveaux revêtements anti-reflets constitués de silice hydrophobe (modifiée méthyle) avec différentes nanostructures (piliers et trous). Ces nouveaux revêtements permettent de réduire la réflexion dans un intervalle spectral large tout en conservant une large tolérance angulaire à la lumière incidente. D’autre part, ces nanomatériaux présentent une stabilité chimique, thermique et mécanique améliorée par rapport à l’état de l’art. Par la suite, un nouveau système de couche sensible composé d’une méta-surface de TiO2 encapsulée dans une matrice hybride microporeuse pour capteur basée sur la transduction optique, et présentant une sensibilité spectrale de 4470 nm/RIU a été développé. Ce dernier a été exploiter pour sonder la présence de COV dans l’air avec une sélectivité partielle et une sensibilité de 0.5×10-3 R/ppm. Finalement, le savoir-faire développé a ensuite été mis à contribution pour l’élaboration de réseaux de méta-surfaces par empilements successifs de matériaux diélectriques SiO2 poreuse et TiO2 dense nano-imprimés. Ce dernier travail est précurseur à la fabrication de méta-matériaux 3D par procédé sol-gel
The purpose of this thesis is to develop methods to elaborate nanostructured metasurfaces by combining sol-gel chemistry and nano imprint lithography (soft-NIL), which are of relevant scientific and technological interest as they inscribe themselves in the general trend of developing affordable and time-saving processes, using biocompatible and non-toxic materials. Firstly, we showcase the elaboration of new efficient antireflection coatings made of water-repellent methylated silica nipple-dimple nano-architectures (pillars and holes). The interest of these results relies on the possibility to drastically reduce reflection in a broad spectral interval and within a broad acceptance angle of the incident light, rendering them adapted to photovoltaic, glass covers, laser windows, and much more. Furthermore, these nano-materials feature a high chemical, thermal and mechanical stability. Secondly, a highly sensitive optical gas sensor was elaborated based on TiO2 nanopatterns embedded in a thin microporous hybrid-SiO2 sensitive coating. The reflectivity of the layer has then been measured in the visible range with increasing vapor pressure. The measured sensing performances are sensitivity S up to 4500 nm/RIU (0.2 nm/ppm), reflection intensity changes up to R* = 17 (0.55×10-3 R/ppm), FOM up to 12, with a Q-Factor of 4 for a specific wavelength, which is compatible with sub-ppm gas detection by simple specular reflection. Finally, a novel generation of dielectric 3D stack nanostructured patterns (e.g. TiO2 pillars - mesoporous SiO2 - TiO2 pillars) was developed as an innovative optical system that has never been experimentally studied before

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Büttner, Lars, Felix Schmieder, Martin Teich, Nektarios Koukourakis, and Jürgen Czarske. "Application of adaptive optics for flexible laser induced ultrasound field generation and uncertainty reduction in measurements." SPIE, 2017. https://tud.qucosa.de/id/qucosa%3A35156.

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The availability of spatial light modulators as standard turnkey components and their ongoing development makes them attractive for a huge variety of optical measurement systems in industry and research. Here, we outline two examples of how optical measurements can benefit from spatial light modulators. Ultrasound testing has become an indispensable tool for industrial inspection. Contact-free measurements can be achieved by laser-induced ultrasound. One disadvantage is that due to the highly divergent sound field of the generated shear waves for a point-wise thermoelastic excitation, only a poor spatial selectivity can be achieved. This problem can be solved by creating an ultrasound focus by means of a ring-like laser intensity distribution, but standard fixed-form optical components used for their generation are always optimised to a fixed set of parameters. Here, we demonstrate, how a predefined intensity pattern as e.g. a ring can be created from an arbitrary input laser beam using a phase-retrieval algorithm to shape an ultrasound focus in the sample. By displaying different patterns on the spatial light modulator, the focus can be traversed in all three directions through the object allowing a fast and highly spatially resolving scanning of the sample. Optical measurements take often place under difficult conditions. They are affected by variations of the refractive index, caused e.g. by phase boundaries between two media of different optical density. This will result in an increased measurement uncertainty or, in the worst case, will cause the measurement to fail. To overcome these limitations, we propose the application of adaptive optics. Optical flow velocity measurements based on image correlation in water that are performed through optical distortions are discussed. We demonstrate how the measurement error induced by refractive index variations can be reduced if a spatial light modulator is used in the measurement setup to compensate for the wavefront distortions.

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Jovan, Bajčetić. "Modelovanje uticaja intenzivnih promena Sunčevog zračenja na prostiranje radio talasa." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2017. https://www.cris.uns.ac.rs/record.jsf?recordId=102468&source=NDLTD&language=en.

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Ova disertacija predstavlja rezultate istraživanja uticaja dve vrsteintenzivnih promena Sunčevog zračenja na prostiranje radio talasa. Prvi deoprikazanih rezultata odnosi se na efekte neperiodičnih zračenja u X-opsegutalasnih dužina u toku trajanja Sunčevog X-flera. Izvršeno je modelovanjekarakteristika jonizovane sredine D-sloja jonosfere u toku celokupnogtrajanja efekata dodatne energije jonizacije i karakteristika prostiranjaradio talasa određenih frekvencijskih opsega u okviru navedene sredine.Drugi deo rezultata prikazuje periodičnu promenu nivoa prijemnog signalausmerene mikrotalasne radio komunikacije koja nastaje u toku jutarnjihčasova. Pokazano je da ova promena ima visok stepen korelisanosti sapromenama vrednosti geomagnetskog polja i da je uzrokuje pojava Sunca nahorizontu. Na osnovu rezultata dobijenih merenjem je predložen model kojiopisuje trend navedene promene u jutarnjim časovima.
This thesis presents the research results of intensive solar radiation variationinfluence on radio propagation. The first part of presented results is related to theeffects of non-periodic radiation within X-ray wavelength during Solar X-flare.Modelling of ionosphere D-layer medium is performed during all time duration ofadditional ionization energy, as well as radio propagation characteristics within thismedium. The second part of the measured results presents periodic variation ofreceiving microwave radio signal level of experimental Line-of-site communicationduring the morning hours. It is shown that this variation is highly correlated withgeomagnetic field component values variation and that is caused by the Sunappearance on the horizon. Based on the experimentally collected results, the modelthat describes this variation during morning hours is proposed.

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Huang, Wei-Yin, and 黃唯音. "The influence of refractive index variation on the performance of ARROW devices." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/67794598628038099020.

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碩士
國立交通大學
電子工程學系
85
In this thesis, we develop the necessary methods to analyze the influence of the refractive index variation for the antiresonant reflectingoptical waveguide (ARROW) devices. For the two dimentional slab ARROW, we usethe characteristic matrix method and beam propagation method (BPM); then compare their results. It can be seen that the performance of a slab ARROW isvery sensitive to the refractive index variation, and we can use this characteristic in dual slab ARROW to design optical switches or various sensors in the future. For the three dimentional strip ARROW, we use the eigenvalue method, the effective index method, and BPM; then compare their results.It can be seen that the performance of a strip ARROW is very good, and its maximum coupling efficiency will not significantly be influenced by the refractive index variation. The results give a useful reference for the designand fabrication of the ARROW devices.

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Lin, You-Shen, and 林祐紳. "Full-field Refractive Index Variation Measurement Based on Phase-type Angle-deviation Method." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/p4n74w.

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碩士
國立虎尾科技大學
光電與材料科技研究所
103
We proposed the phase-type angle-deviation method to measure the full-field of refractive index variation of a liquid.The phase measurement is based on phase-shift interferometry and the use of surface plasmon resonance (SPR) sensor. The phase shift between the s-and p-polarizations due to the angle deviation in SPR sensor is caused by the refractive index variation. The method can plot the full-field image of refractive index in short time and realize the liquid flow status. The SPR sensor can enhance the phase sensitivity and the refractive index resolution can be better than 10-8(RIU).

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Fan, Hsin-Chen, and 范新辰. "Utilizing the laser swept source to detect the micro-variation of refractive index in devices." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3v89p7.

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碩士
國立交通大學
光電系統研究所
106
Refractive index is one of the most important physical parameters in a substance. Once we grasp the refractive index of a substance, then we can understand the optical characteristics, concentration, purity or dispersion of the substance, even the temperature of the object to a certain extent. In this paper, we choose microfluidic channel, which has the advantage of the thinness that can make the Fabry–Pérot phenomenon more obviously, as a container for measuring the small refractive index changes produced by different concentrations of the solution. On the other hand, we use a homemade laser swept source equipped with a galvano mirror, so we can flexibly adjust the scanning frequency in the resonant cavity, and combine a data acquisition card with a high-speed sampling rate to greatly increase the number of sampling points scanned, thereby improving the accuracy of the refractive index which can be calculated. In addition, it’s a non-contacting method of measurement, which can reduce the weight or temperature limitation of the object to be tested. It can also measure a wide range of refractive index. In conclusion, this method for measuring the refractive index is quite ideal.

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Books on the topic "Refractive index variation"

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Center, Lewis Research, ed. Effect of refractive index variation on two-wavelength interferometry for fluid measurements. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, 1998.

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Center, Lewis Research, ed. Effect of refractive index variation on two-wavelength interferometry for fluid measurements. [Cleveland, Ohio]: National Aeronautics and Space Administration, Lewis Research Center, 1998.

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3

Joo, Kyung Ro. Effects of variation of index of refraction of atmosphere on Cerenkov radiation. 1985.

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4

Birch, K. P. Evaluation of the Effect of Variations in the Refractive Index of Air Upon the Uncertainty of Industrial Length Measurements. European Communities / Union (EUR-OP/OOPEC/OPOCE), 1992.

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Book chapters on the topic "Refractive index variation"

1

Tabassum, Rana, and Ravi Kant. "Plasmonic Probing of Refractive Index Variations Using MWCNT@Ta2O5 Core–shell Nanoparticles." In Springer Proceedings in Physics, 339–45. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7691-8_34.

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Newnham, Robert E. "Dispersion and absorption." In Properties of Materials. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198520757.003.0028.

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In this chapter we discuss dispersion, the dependence of the refractive index on wavelength, and absorption that is related to the imaginary part of the refractive index. The variation of the refractive index with temperature (thermo-optic effect) is also described. In terms of their directional behavior, all three of these effects can be represented by second rank tensors because of their relationship to the optical dielectric constant K. The thermo-optic coefficients relate ΔKij to a temperature change

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Newnham, Robert E. "Photoelasticity and acousto-optics." In Properties of Materials. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780198520757.003.0029.

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The change in refractive indices with mechanical stress, the photoelastic effect, is used in analyzing stress patterns in engineering components of complicated shape. It is also important in acousto-optic devices, optical switches, modulators, and scanners in which ultrasonic waves modulate the refractive index, producing an optical grating. Materials with sizable photoelastic coefficients (p) are required to enhance the interaction between mechanical strain x and refractive index n. Changes in the indicatrix are given by These quantities are actually tensors but are treated as scalars in the following discussion which is concerned with the magnitudes of the photoelastic coefficients p, and not their variation with direction. Unlike the linear electro-optic effect, photoelasticity occurs in all symmetry classes and is not a null property. Photoelastic coefficients are dimensionless because strain and refractive index are dimensionless. For most oxides and halides, pmax ≅ 0.2. The maximum values of p measured for other materials range from 0.1 to 0.6. To gain a clearer understanding of the effects of stress on refractive index, consider the effect of hydrostatic pressure on a cubic crystal.

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Meshginqalam, Bahar, Mohammad Taghi Ahmadi, Hamid Toloue Ajili Tousi, Arash Sabatyan, and Anthony Centeno. "Surface Plasmon Resonance-Based Sensor Modeling." In Handbook of Research on Nanoelectronic Sensor Modeling and Applications, 361–94. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0736-9.ch014.

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Exceptional optical and electrical characteristics of graphene based materials attract significant interest of the researchers to develop sensing center of surface Plasmon resonance (SPR) based sensors by graphene application. On the other hand refractive index calculation of graphene based structures is necessary for SPR sensor analysis. In this chapter first of all a new method for refractive index investigation of some graphene based structures are introduced and then the effect of carrier density variant in the form of conductance gradient on graphene based SPR sensor response is modeled. The molecular properties such as electro-negativity, molecular mass, effective group number and effective outer shell factor of the molecule are engaged. In addition each factor effect in the cumulative carrier variation is explored analytically. The refractive index shift equation based on these factors is defined and related coefficients are proposed. Finally a semi-empirical model for interpretation of changes in SPR curve is suggested and tested for some organic molecules.

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Huaraca Aparco, Rosa, María del Carmen Delgado Laime, Fidelia Tapia Tadeo, Henrry Wilfredo Agreda Cerna, Edwin Mescco Cáceres, Juan Alarcón Camacho, Hans Yuri Godoy Medina, et al. "Bioactive Compounds and Antioxidant Activity of Essential Oil of Species of the Genus Tagetes." In Recent Developments in Antioxidants From Natural Sources [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.109254.

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This study investigated the bioactive compounds and antioxidant activity of the essential oil of two species of the genus Tagetes (Tagetes minuta L. and Tagetes elliptica Sm). The essential oil was obtained by steam distillation, and its extraction performance, relative density, refractive index, and solubility in ethanol (70% v/v) were determined. The chemical components were evaluated by gas chromatography coupled to mass spectrometry (GC-MS). Antioxidant activity was determined by the free radical 2,2-diphenyl-1-picrylhydrocyl (DPPH) method and the trapping capacity of the ABTS*+ radical cation. In the essential oils of the species Tagetes, it was possible to identify 26 chemical components for the species Tagetes elliptica Sm. and 16 for Tagetes minuta L., both species presented as main components monoterpenes (61%) and sesquiterpenes (44%). The compounds found were β-myrcene, trans-tagetone, β-trans-ocimene, and β-caryophyllene. Essential oils showed a variation in extraction yields and density. The refractive index was higher in the species Tagetes elliptica Sm., finding a high solubility in both species. A variation was found between 1.77 and 2.56 mg/mL of antioxidant activity by the DPPH method and 21.02–41.06 mg/mL for ABTS*+. The essential oils of the species Tagetes elliptica Sm.y and Tagetes minuta L. have bioactive components with antimicrobial and antioxidant potentialities for use for food preservatives.

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Ayub Hamdani, Mursal, and Gausia Qazi. "Modelling Fabrication Variability in Silicon Photonic Devices." In Photonic Materials: Recent Advances and Emerging Applications, 265–83. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815049756123010016.

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Silicon photonics allows for high yield and complex integration with large processing, packaging, and testing availability. Using silicon as a material leverages the use of the existing CMOS infrastructure with hybrid and epitaxial layer integration, allowing photonic system-on-chip. Although high refractive index contrast with sub micrometer waveguide dimensions allows a dense integration, sensitivity to fabrication variations shows an increased effect. This sensitivity shows a cumulative effect on the optical properties of complex silicon photonic circuits such as lattice filters, and wavelength division multiplexers (WDM). This increases the demand for model fabrication variation at the design stage itself since the fabless users have no insights into the process specifications. As a result, reliability modelling of photonic circuits has shown significant interest in recent years. This is done by using efficient behavioural models at the circuit level and then applying random variations in the model parameters to assess the impact of these variations. In this chapter, different approaches to modelling fabrication variations in photonic integrated circuits, such as Monte Carlo (MC), Stochastic Collocation (SC), and Polynomial Chaos Expansion (PCE) are reviewed. These methods employ random distribution to the varying parameters with the correlation between different parameter sets fixed. Virtual Wafer-based MC (VW-MC) allows layout-aware variability analysis, where the placement of circuit components on the layout coordinates is exported to the circuit design for dependence analysis. Using these methods, mitigation strategies to counter the manufacturing variations such as thermal compensation, and tapered designs are quantitatively evaluated by appropriate yield analysis and design for manufacturability.

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Gahlot, Ajay Pratap Singh. "Optical Dispersion: Variation of Refractive Index of Polypyrrole and SnO2 Nanocomposite Thin Film with Incident Wavelength." In Fundamental Research and Application of Physical Science Vol. 7, 75–81. B P International (a part of SCIENCEDOMAIN International), 2023. http://dx.doi.org/10.9734/bpi/fraps/v7/5977c.

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Shekari Firouzjaei, Ali, Seyed Salman Afghahi, and Ali-Asghar Ebrahimi Valmoozi. "Emerging Trends, Applications, and Fabrication Techniques in Photonic Crystal Technology." In Recent Advances and Trends in Photonic Crystal Technology. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1002455.

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Photonic crystals have emerged as a fascinating field of research and development, offering unprecedented control over the propagation and manipulation of light. These artificial structures are engineered to have periodic variations in refractive index, enabling them to control the behavior of photons in a manner analogous to how crystals manipulate electrons. Recent advancements in photonic crystals have focused on expanding their capabilities and exploring new applications. These advancements and trends in photonic crystals demonstrate their potential to revolutionize various technological domains. From integrated photonics to sensing, quantum information processing to solar energy harvesting, photonic crystals offer unprecedented control over light and pave the way for innovative applications and devices.

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Masters, Barry R., and T. C. So Peter. "Nonlinear Microscopy Applied to Dermatology." In Handbook of Biomedical Nonlinear Optical Microscopy, 797–824. Oxford University PressNew York, NY, 1998. http://dx.doi.org/10.1093/oso/9780195162608.003.0032.

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Abstract The application of nonlinear optical microscopy for tissue imaging has an early start in dermatology and is the subject of an increasing number of studies that are based on nonlinear optical microscopy. The term “dermatology” (Greek derma [skin] Greek logos [study]) was created in the late 1700s (Holubar & Schmidt, 1992). The early adaptation of nonlinear microscopy in dermal studies originates from two factors. First, unlike many internal organs, the accessibility of skin allows nonlinear microscopic imaging in the format of standard laboratory microscopes and does not require surgery or the use of endoscopic technology. Second, skin is a highly scattering tissue with large layer-by-layer variation in refractive index. Therefore, while there is good progress in noninvasive skin imaging using linear optical technology, the superior performance of nonlinear microscopy in highly scattering materials enables more rapid progress to be made in this field. For biomedical applications, the ideal case is to study in vivo human skin using minimally invasive optical imaging and spectroscopy techniques. In practice, this is not always possible, as in vivo imaging techniques do not provide resolution and biochemical information content comparable to that of traditional histology. Furthermore, some measurements, such as the determination of tissue genetic expression profiles, inevitably require specimen excision. When optical imaging can be obtained together with histological skin preparations from the same body region, very good comparison can still be made (Rajadhyaksha, González, et al., 1999). Alternatively, a better understanding of skin physiology can also be obtained by using two different in vivo optical techniques, including nonlinear optical microscopy methods, to study the same region of human in vivo skin (Masters & So, 1999, 2001). In this chapter, we are discussing human skin unless otherwise stated.

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Conference papers on the topic "Refractive index variation"

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Pagano, Robert J., Paul K. Manhart, and Paul T. Sherman. "Measurement of refractive index and dispersion in axial gradient material using prism refractometry." In Gradient-Index Optical Imaging Systems. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/giois.1994.gwa3.

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Axial gradient material is now fabricated via controlled diffusion of glass plates for a wide variety of optical applications. The variation in both refractive index and dispersion, through this new optical material, challenges current refractive index measurement techniques. To provide accurate characterization of refractive index, as a function of thickness, at multiple wavelengths, a prism refractometer was constructed. Multiple laser lines are spatially filtered and passed through a right-angle prism of gradient material. A movable exit slit selects the region under test along the angled back face of the prism. The selected slit of radiation is then retro-reflected back through the prism and the refracted angle is measured directly. By scanning the exit slit along the prism back face, the refractive index variation through the prism is measured at multiple wavelengths. This paper describes, in detail, the test method summarized above and reports on the precision and accuracy of this laboratory test.

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Norland, Richard. "Temporal Variation of the Refractive Index in Coastal Waters." In 2006 International Radar Symposium. IEEE, 2006. http://dx.doi.org/10.1109/irs.2006.4338040.

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Hoefer, Carolyn S. "Thermal Variation Of The Refractive Index In Optical Materials." In 30th Annual Technical Symposium, edited by Larry G. DeShazer. SPIE, 1987. http://dx.doi.org/10.1117/12.939628.

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Li, Wei, Yitao Liang, and Maixia Fu. "The radio propagation affected by variation of refractive index." In 2009 3rd IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications (MAPE). IEEE, 2009. http://dx.doi.org/10.1109/mape.2009.5355602.

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Ghatak, Ajoy K., I. C. Goyal, and Rajeev Jindal. "Modes of waveguides with sinusoidal variation of refractive index." In International Conference on Fiber Optics and Photonics: Selected Papers from Photonics India '98, edited by Anurag Sharma, Banshi D. Gupta, and Ajoy K. Ghatak. SPIE, 1999. http://dx.doi.org/10.1117/12.347991.

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Heo, Duchang, Yun-Seok Kwak, Tae-kyung Kim, and Young-Wook Choi. "Tapered laser diode with linearly effective-refractive-index variation waveguide." In SPIE LASE, edited by Mark S. Zediker. SPIE, 2015. http://dx.doi.org/10.1117/12.2080439.

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Hiware, Sameer, Pradyot Porwal, Rajbabu Velmurugan, and Subhasis Chaudhuri. "Modeling of PSF for refractive index variation in fluorescence microscopy." In 2011 18th IEEE International Conference on Image Processing (ICIP 2011). IEEE, 2011. http://dx.doi.org/10.1109/icip.2011.6115879.

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Nasiri Avanaki, Mohammad Reza, Steven Daveluy, Darius Mehregan, Zahra Turani, rayyan Manwar, and emad fatemizadeh. "Compensation of refractive index variation in optical coherence tomography images." In Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXIII, edited by Joseph A. Izatt and James G. Fujimoto. SPIE, 2019. http://dx.doi.org/10.1117/12.2510561.

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Carniglia, C. K., K. N. Schrader, P. A. O'Connell, and S. R. Tuenge. "Refractive Index Determination using an Orthogonalized Dispersion Equation." In Optical Interference Coatings. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oic.1988.wc3.

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The refractive index n and thickness t of a thin-film coating can be determined from ellipsometric measurements of light reflected from the film. If data are taken over a broad range of wavelengths, then a range of values of n and t are obtained. The variation in n is expected and is a measure of the dispersion of the material. The variation in t, which is often found, results from the failure of a single-layer model to explain the measured data. This may occur because the film is inhomogeneous or anisotropic.

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Feise, D., G. Blume, Chr Kaspari, K. Paschke, and G. Erbert. "Variation of refractive index step of 635nm ridge waveguide lasers for optimized index guiding." In SPIE LASE. SPIE, 2011. http://dx.doi.org/10.1117/12.873397.

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Reports on the topic "Refractive index variation"

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Sommargren, G. E., D. W. Phillion, M. A. Johnson, and L. S. Bradsher. Measurement of the Variations in Thickness and Refractive Index of NIF Crystals. Office of Scientific and Technical Information (OSTI), January 2002. http://dx.doi.org/10.2172/15002093.

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Ostashev, Vladimir, Michael Muhlestein, and D. Wilson. Extra-wide-angle parabolic equations in motionless and moving media. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/42043.

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Wide-angle parabolic equations (WAPEs) play an important role in physics. They are derived by an expansion of a square-root pseudo-differential operator in one-way wave equations, and then solved by finite-difference techniques. In the present paper, a different approach is suggested. The starting point is an extra-wide-angle parabolic equation (EWAPE) valid for small variations of the refractive index of a medium. This equation is written in an integral form, solved by a perturbation technique, and transformed to the spectral domain. The resulting split-step spectral algorithm for the EWAPE accounts for the propagation angles up to 90° with respect to the nominal direction. This EWAPE is also generalized to large variations in the refractive index. It is shown that WAPEs known in the literature are particular cases of the two EWAPEs. This provides an alternative derivation of the WAPEs, enables a better understanding of the underlying physics and ranges of their applicability, and opens an opportunity for innovative algorithms. Sound propagation in both motionless and moving media is considered. The split-step spectral algorithm is particularly useful in the latter case since complicated partial derivatives of the sound pressure and medium velocity reduce to wave vectors (essentially, propagation angles) in the spectral domain.

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