Academic literature on the topic 'Frustrated Total Internal Reflection (FTIR)'
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Journal articles on the topic "Frustrated Total Internal Reflection (FTIR)":
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Martinez, J. C. "Confronting the Hartman effect with data from frustrated total internal reflection (FTIR)." Laser Physics 16, no. 7 (July 2006): 1123–27. http://dx.doi.org/10.1134/s1054660x06070176.
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Hial, Qahtan Ghatih. "Frustrated total internal reflection of newton rings multiple beam interference." Iraqi Journal of Physics (IJP) 15, no. 35 (October 2, 2018): 29–39. http://dx.doi.org/10.30723/ijp.v15i35.51.
Abstract:
Frustrated Total Internal Reflection FTIR phenomenon is manifested employing Newton‟s rings setup generated via a coherent light beam of a laser diode ( . All concentric bright and dark rings, except the central bright spot, were noticed to recede (disappear) when the incident angle exceeded the critical angle of 41o.It was also shown that the current setup has proven its applicability for other tests and can give convenient results that conform with theory. Neither the concept nor the design is beyond what can be realized in an undergraduate laboratory. However, technical improvements in mounting the prism - lens may be advisable. As an extension of the experiments, the effect can be studied using hollow prism filled with liquids of different refractive indices for both S and P polarizations of light. Also, the relationship of wavelength on the penetration depth can be explored.
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Kolhe, Neel, and Sreyashi Shetty. "A novel cantenna based demonstration of frustrated total internal reflection as an analog for quantum tunnelling." Physics Education 58, no. 2 (January 11, 2023): 025011. http://dx.doi.org/10.1088/1361-6552/acad59.
Abstract:
Abstract We use a ‘Cantenna’ (portmanteau of ‘Can’ and ‘Antenna’), which is a unidirectional homemade waveguide, coupled to a standard readily available, 2.4 GHz Wi-Fi router as a source of microwaves to demonstrate Frustrated Total Internal reflection (FTIR) using paraffin-wax prisms. This largely inexpensive experiment provides an opportunity to demonstrate a process closely analogous to quantum tunnelling in an undergraduate physics lab. FTIR is often demonstrated with glass prisms and lasers, which may not allow for an intuitive understanding of evanescent waves and tunnelling. Wi-Fi signals with a wavelength of 12.5 cm, and large maneuverable prisms, allow the length of the ‘barrier’ to be changed in a tactile way where measurements could be taken with tools available in a standard physics lab.
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Голубцова, Ю. В. "ОЦЕНКА КАЧЕСТВА И ПОДЛИННОСТИ ПЛОДОВО-ЯГОДНОГО СЫРЬЯ МЕТОДОМ ИК-ФУРЬЕ СПЕКТРОСКОПИИ НАРУШЕННОГО ПОЛНОГО ВНУТРЕННЕГО ОТРАЖЕНИЯ." ТЕХНИКА И ТЕХНОЛОГИЯ ПИЩЕВЫХ ПРОИЗВОДСТВ 2, no. 45 (June 23, 2017): 126–32. http://dx.doi.org/10.21179/2074-9414-2017-2-126-132.
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Lin, Jhe-Syuan, and Wen-Shing Sun. "A Hidden Fingerprint Device on an Opaque Display Panel." Applied Sciences 10, no. 6 (March 23, 2020): 2188. http://dx.doi.org/10.3390/app10062188.
Abstract:
In recent years, fingerprint recognition has become more and more widely used in mobile phones. A fingerprint recognition device hidden under an opaque display panel designed based on a waveguide and frustrated total internal reflection (FTIR) is proposed and demonstrated herein. In order to meet the demand for a high screen ratio for mobile phone displays, we use a symmetrical zoom-in and zoom-out coupler design. With this comprehensive coupler and waveguide design, not only can fingerprint recognition be achieved using an opaque display panel, but it also meets the appearance requirements for a mobile phone with a high screen ratio.
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Жуков, Н. Д., А. Г. Роках, and М. И. Шишкин. "Свойства наночастиц сульфида свинца в мультизеренной структуре." Физика и техника полупроводников 52, no. 6 (2018): 608. http://dx.doi.org/10.21883/ftp.2018.06.45924.8686.
Abstract:
AbstractThe structural and electrical properties of PbS nanoparticles (40–70 nm), produced by a chemical reaction of sodium hydroxide with lead nitrate and electrophoretically deposited onto a conductive substrate, are investigated. The composition and structure of the nanoparticles are identified by X-ray analysis as pure PbS phase with a face-centered cubic lattice. Several minima, related to plasma-resonance absorption at 10–17 μm, are observed in the frustrated total internal reflection (FTIR) spectra. The layer morphology and the nanoparticle shape and sizes are determined by scanning electron and tunneling microscopy. The threedimensional topograms show that the surface fine structure is a set of faceted pyramidal spikes with a size of 5–10 nm and a density of ~400 μm^–2. An analysis of the tunneling current–voltage characteristics of individual nanospikes shows the presence of low-field emission and makes it possible to determine the barrier heights (1.6–1.8 eV), which are explained within the quantum-dot (QD) model.
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Brodie, Graham, and Grigory Torgovnikov. "Microwave Soil Heating with Evanescent Fields from Slow-Wave Comb and Ceramic Applicators." Energies 15, no. 3 (January 31, 2022): 1068. http://dx.doi.org/10.3390/en15031068.
Abstract:
Microwave soil heating deactivates weed seeds; however, in many modern agricultural settings, weed seeds are mostly found in the top 1–2 cm of the soil profile. Until recently, microwave soil heating has been achieved using various antennas, which project the microwave energy deeply into the soil. The aim of this research was to develop new microwave applicators that provide shallow heating (less than 50 mm). This paper presents two applicator designs, one based on a comb slow-wave structure and the other on the frustrated total internal reflection (FTIR) principle, which utilise evanescent microwave fields to restrict the depth of microwave heating. The background theory to their performance is presented, followed by experimental evidence of their constrained heating performance under different soil moisture scenarios. Experimental measurements of the heating performance of these applicators, in soils of varying moisture content, demonstrate that the evanescent microwave fields restrict the depth of heating, so that most of the energy is manifested in the top 50 mm of soil. The evanescent field decay rate for the FTIR applicator changes from 44.0 ± 0.7 m−1 to 30 ± 1.2 m−1 as the soil moisture changes from 32% to 174% (dry weight basis). This is higher than the evanescent field decay rate for the comb slow-wave applicator (17.6 ± 0.7 m−1 to 19.9 ± 1.5 m−1). The FTIR applicator has a wider and shallower heating pattern than the comb slow-wave applicator. Because of the double heating lobes of the FTIR applicator, the effective half temperature heating width is approximately 150 mm. This is wider than the half temperature heating width of the comb slow-wave applicator (95 mm).
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Becchetti, Matteo, Roberto Marsili, Ferdinando Cannella, and Alberto Garinei. "A new system for the measurement of gripping force based on scattering." ACTA IMEKO 6, no. 4 (December 28, 2017): 100. http://dx.doi.org/10.21014/acta_imeko.v6i4.481.
Abstract:
<p style="margin: 0cm 0cm 0pt;"><span lang="EN-US"><span style="font-family: Calibri; font-size: small;">The measurement of contact pressure of human fingers is very important to understand human perceptual mechanisms, that is the main goal of most of the neuroscientific studies. It may also lead to a correct development of tactile devices and haptic systems, as they are intended to convey controllable and effective stimuli.</span></span></p><span style="font-family: 'Garamond','serif'; font-size: 10pt; mso-bidi-font-size: 12.0pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB">In this work, an optical measurement system based on Frustrated Total Internal Reflection (FTIR) is proposed for the measurement of the pressure distribution on the contact area between a human finger and a flat surface. The feasibility study performed shows that the tested sensor can be effectively used for the measurement of the fingertip contact pressure both on static and dynamic conditions.</span>
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Borković, Katarina, and Andreana Ćurić. "“Tap, Tap Water”. Quantum Tunneling Demonstration." Natural Science and Advanced Technology Education 31, no. 4 (August 1, 2022): 359–70. http://dx.doi.org/10.53656/nat2022-4.04.
Abstract:
Quantum tunneling is a phenomenon in which an atom or a subatomic particle appears on the other side of a potential barrier that should be impenetrable to the particle, given the difference between the kinetic energy of the particle and the potential energy of the barrier, the former being significantly lesser. However, if the barrier shrinks enough the particle will be able to tunnel right through it. This is among the most well-known quantum physics phenomena. Historically, physicists struggled to grasp the wavelike and particle-like duality of light and subatomic particles. The aforementioned phenomenon occurs due to the wavelike behavior of photons. Quantum phenomena, such as quantum tunneling, might appear quite convoluted, therefore a simple experimental demonstration was performed to highlight the basic mechanisms of the phenomenon in a manner comprehensible to the wide masses. The demonstration, however, is just what we are in fact observing instead of quantum tunneling – “optical tunneling”, perhaps more commonly known as Frustrated Total Internal Reflection (FTIR). This mathematically analogous phenomenon serves as a mere tool for explaining quantum tunneling while aiding our understanding of it and facilitating its visualization. The experimental demonstration shall prove that quantum tunneling is a daily occurring phenomenon and that it is possible once the barrier is thin enough. If these arguments are indeed met with a successful visual demonstration a wavelike character of the photons happens to be confirmed as well.
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Hernandez, Alyssa M., Jessica A. Sandoval, Michelle C. Yuen, and Robert J. Wood. "Stickiness in shear: stiffness, shape, and sealing in bioinspired suction cups affect shear performance on diverse surfaces." Bioinspiration & Biomimetics 19, no. 3 (March 26, 2024): 036008. http://dx.doi.org/10.1088/1748-3190/ad2c21.
Abstract:
Abstract Aquatic organisms utilizing attachment often contend with unpredictable environments that can dislodge them from substrates. To counter these forces, many organisms (e.g. fish, cephalopods) have evolved suction-based organs for adhesion. Morphology is diverse, with some disc shapes deviating from a circle to more ovate designs. Inspired by the diversity of multiple aquatic species, we investigated how bioinspired cups with different disc shapes performed in shear loading conditions. These experiments highlighted pertinent physical characteristics found in biological discs (regions of stiffness, flattened margins, a sealing rim), as well as ecologically relevant shearing conditions. Disc shapes of fabricated cups included a standard circle, ellipses, and other bioinspired designs. To consider the effects of sealing, these stiff silicone cups were produced with and without a soft rim. Cups were tested using a force-sensing robotic arm, which directionally sheared them across surfaces of varying roughness and compliance in wet conditions while measuring force. In multiple surface and shearing conditions, elliptical and teardrop shapes outperformed the circle, which suggests that disc shape and distribution of stiffness may play an important role in resisting shear. Additionally, incorporating a soft rim increased cup performance on rougher substrates, highlighting interactions between the cup materials and surfaces asperities. To better understand how these cup designs may resist shear, we also utilized a visualization technique (frustrated total internal reflection; FTIR) to quantify how contact area evolves as the cup is sheared.
Dissertations / Theses on the topic "Frustrated Total Internal Reflection (FTIR)":
1
Rahnavardy, Kambiz. "Investigation and application of the Frustrated-Total-Internal-Reflection phenomenon in optical fibers." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-11072008-063335/.
2
Alagao, Mary Angelie. "Characterization and optimization of the Evanescent Wave Coronagraph." Electronic Thesis or Diss., Saint-Etienne, 2023. http://www.theses.fr/2023STET0060.
Abstract:
L’imagerie directe des exoplanètes reste difficile en raison du contraste élevé et de la faible séparation angulaire entre l'étoile et la planète. Cela nécessite de supprimer l'éblouissement dû à l'étoile et de s'assurer que la lumière faible de la planète n'est pas noyée au milieu de divers bruits. La détection dépend de la maturité des techniques et des algorithmes utilisés, tout en tenant compte des compromis importants sur le contraste brut, la résolution angulaire et la transmission. L'une de ses composantes clés est l'utilisation de coronagraphes - des instruments ayant pour seul but de bloquer/réduire la lumière provenant de l'étoile. Ce travail présente un nouveau type de coronographe de Lyot, inventé par le Dr Yves Rabbia, qui repose sur le principe de la réflexion interne totale frustrée (FTIR) pour supprimer la lumière de l'étoile. Ce coronographe est appelé Evanescent Wave Coronagraph (EvWaCo) en raison de sa nature : son masque au plan focal, comprenant une lentille et un prisme, réfléchit la source hors axe (planète) et transmet la source sur l'axe (étoile) à l’aide des ondes évanescentes. Cette thèse vise à fournir au lecteur les bases qui mettent en évidence les trois principaux avantages d'EvWaCo : i) le masque est intrinsèquement achromatique, ii) la taille du masque est ajustable en modifiant la pression entre la lentille et le prisme, et iii) à la fois la lumière stellaire et la lumière planétaire peuvent être collectées simultanément pour une détection de front d'onde de bas ordre et un centrage approprié de l’étoile. Les performances d'EvWaCo sont évaluées à travers des expériences en laboratoire, puis comparées à des simulations numériques. Les résultats expérimentaux montrent un contraste brut égal à quelques 10-4 à 3 ��/�� sur toute la bande I (��c = 800 nm, ∆��/�� ≈ 20%) et à 4 ��/�� sur toute la bande R (��c = 650 nm, ∆��/�� ≈ 23%). Les simulations confirment la capacité de rejet achromatique d'EvWaCo, montrant un contraste brut de 10-4 à la même distance radiale sur les deux bandes spectrales. Cette thèse se conclut sur un bilan de l’état du banc développé et les perspectives futuresDirect imaging of exoplanets remains challenging due to the high contrast and the small angular separation between the star and the planet. It requires suppressing the blinding glare from the star and ensuring that the planet's faint light is not buried deep in various noises. Successful detection depends on the technological readiness and maturity of techniques and algorithms employed while considering the significant trade-offs on raw contrast, inner working angle, and throughput. One of its key components is the use of coronagraphs – instruments with the sole purpose of blocking/reducing the light from the star. This work presents a new type of Lyot coronagraph, invented by Dr. Yves Rabbia, that relies on the frustrated total internal reflection (FTIR) principle to suppress the starlight. This coronagraph is aptly called the Evanescent Wave Coronagraph (EvWaCo) owing to its nature that its focal plane mask, comprising a lens and a prism, reflects the off-axis source (planet) and transmits the on-axis source (star) by capturing the evanescent waves. This thesis aims to provide the reader with the groundwork that highlights EvWaCo's three main advantages: i) the mask is inherently achromatic, ii) the size of the mask is adjustable by changing the pressure between the lens and the prism, and iii) both the stellar light and the planet light can be collected simultaneously for low-order wavefront sensing, and proper stellar light centering. The performance of EvWaCo is assessed through experiments in a laboratory and then compared to numerical simulations. The experimental results show a raw contrast equal to a few 10-4 at 3 ��/�� over the full I-band (��c = 800 nm, ∆��/�� ≈ 20%) and at 4 ��/�� over the full R-band (��c = 650 nm, ∆��/�� ≈ 23%). The simulations confirm the achromatic rejection capability of EvWaCo as it showed a raw contrast of 10-4 at the same radial distance over both bandpasses. This thesis concludes with the status of its testbed and future perspectives
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CAMPOS, CARLOS ANDRE TAVARES. "COMPONENTS OF A MULTITOUCH SYSTEM BASED ON FRUSTRATED TOTAL INTERNAL REFLECTION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14013@1.
Abstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROOs sistemas multi-toque (multitouch) estão se tornando cada vez mais utilizados, substituindo a tradicional interface humano-computador baseada em mouse (WIMP interfaces). Um sistema multi-toque pode se basear no fenômeno físico da reflexão interna total confinada (FTIR) da luz numa superfície de acrílico. Com o barateamento dos projetores e câmeras, a construção de mesas e painéis multi-toque se tornou uma possibilidade viável para universidades e empresas. Naturalmente, a qualidade desses sistemas depende do ajuste dos materiais, das luzes, das câmeras e dos projetores utilizados. Este assunto é ainda uma área em aberto, com pouca literatura disponível tendo em vista seus aspectos comerciais. Esta dissertação apresenta um estudo sobre a construção de mesas e painéis multi-toque com base em equipamentos e materiais de baixo custo. O princípio geral de funcionamento e a tecnologia de cada componente são discutidos. Um protótipo foi construído para avaliar o comportamento de cada componente. Com base nos resultados obtidos são apresentadas algumas conclusões e sugestões para trabalhos futuros.
Multitouch systems are becoming more popular replacing traditional WIMP user interfaces. A multitouch system can be based on frustrated total internal refraction of the light in an acrylic surface. With the use of commodity projectors and cameras these systems are now becoming widely affordable. Naturally the quality of these systems depends upon the right choice of material, lights, cameras and projectors. Giving its importance, there is a need for more information on this subject in the literature. This thesis presents the general design of a multitouch systems and a detailed discussion of the expected behavior of each component. A prototype was built to evaluate the proposed solution. Results are discussed to support some conclusions and suggestions of future work.
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Reddy, Perla Siva. "Embedded Multilayer Thin Film Stacks as Polarizing Beam Splitters and Wave Retarders Operating under Condition of Frustrated Total Internal Reflection." ScholarWorks@UNO, 2007. http://scholarworks.uno.edu/td/1079.
Abstract:
The polarization properties of embedded centro-symmetric and periodic multilayer stacks under conditions of frustrated total internal reflection (FTIR) are considered. The centro-symmetric multilayer stack consists of a high-index center layer sandwiched between two identical low-index films and high-index – low-index bilayers repeated on both sides of the central trilayer maintaining the symmetry of the entire stack. The periodic multilayer consists of periodically repeated low-index – high-index bilayers. Each multilayer stack is embedded in a high-index prism. Embedded centro-symmetric multilayer stacks are designed to function as efficient polarizers or polarizing beam splitters (PBSs) under conditions of FTIR over an extended range of incidence angles. For a given set of refractive indices, all possible solutions for the thicknesses of the layers that suppress the reflection of p-polarized light at a specified angle, and the associated reflectance of the system for the orthogonal s polarization, are determined. The angular and spectral sensitivities of polarizing multilayer stacks employing 3, 7, 11, 15 and 19 layers of BaF2 and PbTe thin films embedded in a ZnS prism, operating at ë = 10.6 ìm, are presented. Embedded centro-symmetric multilayer stacks are also designed to function as complete-transmission quarter-wave or half-wave retardation (QWR or HWR) devices under conditions of FTIR. QWR and HWR designs at ë =1.55 mì are presented that employ 11 and 7 layers of Si and SiO2 thin films embedded in GaP and Si cube prisms, respectively. The angular and spectral sensitivities of these devices are also considered. Embedded centro-symmetric multilayer stacks under FTIR conditions are also designed to produce various 50%-50% beam splitters. Embedded periodic multilayer stacks are designed to function as polarizers and PBSs at discrete multiple angles of incidence and wavelengths under condition of FTIR. For a given set of refractive indices, all possible solutions for the thicknesses of the layers that suppress the reflection of p-polarized light at a specified angle, and the associated reflectance of the system for the orthogonal s polarization, are determined. The angular and spectral sensitivities of polarizing multilayer stacks employing 4, 6, 8, 10, 12, 14, 16 and 18 layers of BaF2 and PbTe thin films embedded in a ZnS prism, operating at ë= 10.6 ìm, are presented.
5
Gaufillet, Fabian. "Cristaux photoniques à gradient : dispositifs et applications." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112295.
Abstract:
Les matériaux artificiellement structurés que sont les cristaux photoniques sont couramment utilisés pour leurs propriétés dispersives. Leur constante diélectrique varie périodiquement à l'échelle de la longueur d'onde selon deux ou trois directions avec un contraste d'indice suffisamment élevé. La relation de dispersion ω = ω(k) qui résulte de cette variation périodique a la forme d'une structure de bande à l'intérieur de laquelle il existe des bandes interdites photoniques où la propagation du champ électromagnétique est interdite. En dehors de ces bandes, i.e. dans les bandes photoniques, se trouvent les propriétés de dispersion des cristaux photoniques.Le but de ce travail de thèse est de concevoir, de fabriquer et de caractériser des dispositifs à cristal photonique à gradient. Ces dispositifs ont été conçus de façon à s'appliquer dans les domaines allant des micro-ondes à l'optique. Nous avons conçu des dispositifs à partir de cristaux photoniques dont les propriétés dispersives les rendent analogues à des milieux linéaires, homogènes et isotropes (LHI). À la maille élémentaire de ces cristaux photoniques LHI, nous avons appliqué un gradient pour réaliser des lentilles à gradient 1D. Des résultats importants concernant la conception, la fabrication et la caractérisation expérimentale d'une lentille plate à gradient d'indice fonctionnant dans la bande X des micro-ondes sont reportés. Celle lentille focalise une onde plane incidente et collimate l'onde émise par une source ponctuelle situés dans son plan focal. Si cette lentille constitue en soi un démonstrateur et valide la démarche mise en œuvre pour la concevoir, ses applications potentielles concernent particulièrement les antennes. Nous réalisons également plusieurs lentilles à gradient 2D dont des lentilles de Lüneburg et Half Maxwell Fisheye; leurs applications aux antennes sont importantes. Nous nous intéressons aussi à la réalisation de lentilles optiques à gradient d'indice dites « SELFOC® ». Dans le but de confirmer les propriétés dispersives remarquables qui ont été mises en évidence, nous avons poursuivi dans ce sens en revisitant une expérience classique qui met en évidence l'existence des ondes évanescentes : celle du « double prisme à angle droit ». Nous mettons également en évidence le phénomène de « réflexion totale frustrée » ainsi que le décalage, découvert par Goos et Hänchen, que subit l'onde réfléchie sur le dioptre. Ce sont ces deux points — réflexion totale frustrée et effet Goos-Hänchen — que nous vérifions dans le cas de cristaux photoniques LHIArtificially structured materials that are photonic crystals are commonly used for their dispersive properties. Their dielectric constant varies periodically across the wavelength in two or three directions with a sufficiently high index contrast. The resulting dispersion relation ω = ω(k) of the periodic variation has the form of a band structure within which there are photonic bandgaps in which the propagation of the electromagnetic field is prohibited. Outside of these bands, i.e. in the photonic band, there are the dispersion properties of the photonic crystals.The aim of this thesis is to design, fabricate and characterize graded photonic crystal devices. These devices were designed to be applied in areas ranging from microwaves to optics. We designed devices from photonic crystals with dispersive properties which make them similar to linear, homogeneous and isotropic media (LHI). In the unit cell of the LHI photonic crystal, we applied a gradient to achieve 1D graded lenses. Important results regarding the design, manufacturing and experimental characterization of a flat lens GRIN operating in X-band microwaves are deferred. This lens focuses an incident plane wave and collimates the wave emitted by a point source located in its focal plane. If this lens is itself a demonstrator and validates the approach implemented for the design, its potential applications particularly concern antennas. We also carry several 2D graded lenses including Lüneburg and Half Maxwell Fisheye lenses; their applications to the antennas are important. We are also interested in making optical graded index lenses called "SELFOC®".In order to confirm the remarkable dispersive properties that have been identified, we continued in that direction by revisiting a classic experiment that highlights the existence of evanescent waves: the "double right angle prism". We also highlight the phenomenon of "frustrated total internal reflection" and the shift discovered by Goos and Hänchen suffered by the reflected wave on the interface. It's these two points – frustrated total internal reflection and Goos-Hänchen effect - that we check in the case of LHI photonic crystals
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Hernandez, Felipe Bueno. "Sensor de força utilizando Fiber taper." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-27072016-074912/.
Abstract:
Este trabalho teve por objetivo desenvolver e caracterizar um sensor de força utilizando uma fibra óptica modificada pelo processo conhecido como Fiber tapering. A fibra quando modificada deixa exposto o campo evanescente, o que a torna sensível a influências externas, e a luz guiada na fibra pode vir a sofrer reflexão interna total frustrada ao entrar em contato com materiais. Ao envolver a região modificada por um material elastomérico, a área de contato e consequentemente a atenuação torna-se uma função da intensidade da força aplicada, possibilitando então relacionar a força a atenuação da luz. Baseando-se nesse efeito, foi criado um sensor de dimensões reduzidas, de rápida resposta, linear, altamente sensível e de boa repetibilidade. Foi criado também um circuito eletrônico utilizando amplificadores operacionais para a aquisição e processamento do sinal proveniente da fibra e selecionado um sensor comercial comum para a realização de experimentos e comparações. Ambos os sensores foram posicionados sobre uma balança de precisão e submetidos a diversos esforços obtendo-se dados sobre a resposta estática. Em seguida utilizando um shaker eletrodinâmico foram medidos os tempos de resposta a uma entrada degrau, e realizando esforços repetitivos foram analisados os desvios das medidas lidas pelos sensores.The aim of this research was to develop and characterize a force sensor using a modified optical fiber by a process known as Fiber tapering. The modified fiber leaves the evanescent field exposed and prone to external influences and the guided light may suffer frustration of total internal reflection upon contact with materials. When covering the modified fiber section with an elastomeric material, the contact area and therefore the attenuation becomes a function of the applied pressure, making it possible to relate force to attenuation in light intensity. Based on this effect, a small sensor was created, having a quick response time, with high linearity, high sensitivity and good repeatability. Along with the sensor, an electronic circuit using operational amplifiers was designed for acquisition and processing of the signal obtained from the optical fiber. In addition, in order to perform experiments and comparisons, a standard force sensor was chosen. Both sensors were placed over a precision weighing scale and had different intensities of force applied on them, and after that, data regarding static measurements was gathered. The response time was obtained using an electrodynamic shaker and applying a step input. Furthermore, data was gathered about the deviations on the measurements by performing a repetitive set of compressions.
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Lin, Yi-Shu, and 林義書. "Analysis of Frustrated Total Internal Reflection (FTIR) Multi-touch Mode." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/38868223314541268555.
Abstract:
碩士義守大學
機械與自動化工程學系碩士在職專班
101
There are many different methods for detecting multi-touches on the device surfaces, which all have their advantages and disadvantages. Some of the methods require a lot of pressure to be activated; others are activated even if the user is only close to the surface. Most of the technologies are only used to detect touches, but some of the technologies can be used to detect hands. To use these advantages and overcome their disadvantages should be researched in the future. This study presents an optical technology, which are called Frustrated Total Internal Reflection (FTIR). This technology worked with infrared light reflected by fingertips, captured by an IR-sensitive camera. The multi-touch positions were determined through the well-known software. A tabletop hardware setup is successfully presented, which combines the FTIR eequipment included of the acrylic plate, the array IR-LED lights, a cameras, and a projector, etc.. In the process of this study easy to use software was developed by NUI group, for rapidly testing various processing steps which are needed for the detection process. Additionally, three different thickness of the complaint layer were investigated for the touching performance, namely 0.1-mm- PET, 1.0-mm- PVC and 3.0-mm-thickness PVC, respectively. Experimental results show that 1.0-mm-thickness PVC demonstrated a higher multi-touch sensitivity. With this FTIR system, images can be captured, preprocessed, analyzed, resulting information post-processed and afterwards sent to an application.
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Huang, Hsin-Yuan, and 黃薪源. "Turbidity Monitoring of Electrical Discharge Machining by Frustrated Total Internal Reflection." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5963dj.
Abstract:
碩士國立中央大學
光機電工程研究所
106
The purpose of this study is to develop an optical turbidity measured system. The concentration of EDM neutral oil is an important parameter in the EDM. According to measuring the turbidity of EDM neutral oil changing the velocity of jet flow and we can reduce the carbon deposition to stay on the processing surface, so that the processing environment to maintain the best processing concentration. To improve the machining precision and life of EDM.
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CHEN, REN-FONG, and 陳人鳳. "Fingerprint Image Mosaicking and Recognition Based on Frustrated Total Internal Reflection." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/zn7b7c.
Abstract:
碩士國立臺北科技大學
資訊工程系
107
Although capacitive fingerprint technology is a mature technology, and optical fingerprint technology has matured in recent years, fingerprint images generated by FTIR technology has difficulty in covering a large range of fingerprint areas, the resolution of the fingerprint image is not good also, and difficult to have a stable fingerprint texture contour shape cause the same fingerprint to be non-reproduced becuse of to reduce hardware space for applied to embedded systems. The characteristics of the above-mentioned fingerprint image are greatly different from the fingerprint image those taken by the capacitive fingerprint sensor, and the fingerprint image commonly used fingerprint mosaicking and identification algorithm are all taken out by the capacitive fingerprint sensor, so the algorithm cannot be applied on the images thoses taken by the FTIR fingerprint sensor. In order to solve the above problems, this paper proposes a lightweight system based on the comparison calculation algorithm for a descriptor whose describe the features of the block, and using this to mosaicking and identifying fingerprint images. The descriptor has high tolerance to uneven brightness, and also allows mosaicking and identification comparison in the case of slight distortion of the fingerprint ridge. In the calculation algorithm of the comparison, the matrix operation is used to calculate the similarity between the descriptor. The similarity is used to match the descriptor, and the RANSAC is used to filter out the wrong matching. In addition, the system also corrects the distortion of the fingerprint image generated by the FTIR technology. The fingerprint identification results of the system proposed in this paper are more stable than those existing descriptor matching algorithm. In the low-resolution fingerprint image with poor texture reproducibility, this paper has a more stable result of the identification.
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"Applications of frustrated total internal reflection for short interaction length devices in photonic integrated circuits." SOUTHERN METHODIST UNIVERSITY, 2010. http://pqdtopen.proquest.com/#viewpdf?dispub=3366145.
Books on the topic "Frustrated Total Internal Reflection (FTIR)":
1
Hong, L. Frustrated total internal reflection sensors for colourimetric chemical analysis. Manchester: UMIST, 1995.
Book chapters on the topic "Frustrated Total Internal Reflection (FTIR)":
1
Carey, John J., Justyna Zawadzka, Dino A. Jaroszynski, and Klaas Wynne. "THz-Pulse Studies of Superluminal Propagation in Frustrated Total Internal Reflection." In Ultrafast Phenomena XII, 238–40. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-642-56546-5_71.
2
Mularski, Anna, Florence Marie-Anaïs, Julie Mazzolini, and Florence Niedergang. "Observing Frustrated Phagocytosis and Phagosome Formation and Closure Using Total Internal Reflection Fluorescence Microscopy (TIRFM)." In Macrophages, 165–75. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-7837-3_16.
Conference papers on the topic "Frustrated Total Internal Reflection (FTIR)":
1
Almeida, A. L., M. Huang, F. Cegla, B. Lan, and P. Huang. "Frustrated total internal reflection of ultrasonic waves at a fluid-coupled elastic plate." In ASNT Research Symposium 2023. The American Society for Nondestructive Testing Inc., 2023. http://dx.doi.org/10.32548/rs.2023.054.
Abstract:
A theoretical treatment of frustrated total internal reflection (FTIR) of ultrasonic waves is presented and validated against experimental data. Two different methods are used to derive theoretical models capable of studying transmission of ultrasonic waves through a fluid-coupled elastic plate. First, a multiple reflections approach is used and shown to be inadequate for incident angles beyond the first critical angle. After that, a potentials-based model provided accurate predictions for a thin air-coupled steel sheet. The model helped forge a relation between the transmitted power and the dispersion curves for guided waves in the plate, highlighting the two fundamental causes of FTIR in such systems. The first one is that a thin plate, when compared to the wavelength of the incident wave, will always be subjected to FTIR, as the evanescent wave can never assume negligible values. But more surprisingly, the excitation of the fundamental antisymmetric mode 𝐴0 of the plate is directly related to FTIR for thicker plates.
2
Högele, A., C. Ziolek, H. Lubatschowski, and W. Ertmer. "Frustrated Total Internal Reflection Q-switched Er:YAG and CrEr:YSGG Lasers." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/cleo_europe.1996.cthm3.
Abstract:
Q-switched Er:YAG and CrEr:YSGG lasers are of great interest for many applications in laser medicine and time resolved infrared spectroscopy due to the very high absorption of the 3 µm- radiation in water. The light modulators based on the effect of frustrated total internal reflection (FTIR) [1] appear to be very well suited for Q-switching of these lasers [2, 3, 4]. In this paper, the results of Q-switching of 2.94 µm Er:YAG, 2.79 pm and 2.70 µm CrEr:YSGG lasers with a specially developed FTIR modulator [4] will be presented. The wavelength of 2.70 pm is generated with a CrEr:YSGG laser in a dispersive resonator [4]. The energy output curves of single giant pulses are shown in Fig. 1. The correlations between the pulse energy and the pulse width for these wavelengths in the Q-switching regime have been investigated (Fig. 2). Ablation rates of corneal tissue at different fluences and histological evaluation of the laser induced thermal damage will also be presented and discussed. As a result, Q-switched erbium lasers seem to be a promising tool for many applications in laser surgery. This work is supported by the BMBF (german department for education, research, and technology) within the contract 13N6346/0.
3
Bosacchi, Bruno. "Optical sensors based on frustrated total reflection resonance." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/oam.1989.thnn4.
Abstract:
We discuss the use of the resonant FTR (frustrated total reflection) concept to enhance the sensitivity of internal reflection optical sensors. In a resonant FTR cavity, radiation of a given wavelength is trapped and bounced back and forth until, if even a minute amount of absorption is present, the radiation is eventually totally absorbed.1 Such a cavity, tuned on the absorption line of the substance to be detected in a gas or in a solution, can be straightforwardly incorporated in a conventional internal reflection optical sensor, leading to a sensitivity enhancement of the order of 2 or 3 orders of magnitude. We discuss in particular the detection of CH4 in air and show that the resonant FTR approach allows the detection of concentrations of 0.01%, which represents a 2 order of magnitude improvement over the sensitivity threshold recently achieved with fiber optic sensors.2 We also discuss the resonant FTR approach in comparison with the plasmon resonance approach, which has been recently proposed by several groups, and show that, although they have comparable sensitivity, the FTR approach has important practical advantages.
4
Bufetova, G. A., D. A. Nikolaev, P. R. Lakhno, I. A. Shcherbakov, and V. B. Tsvetkov. "Long pulse lasing of Nd-lasers while using FTIR Q-switches." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1998. http://dx.doi.org/10.1364/cleo_europe.1998.ctui4.
Abstract:
The lasing efficiency in the Q-switch mode depends most of all on the losses, incoming with all the optical elements and the density of the intracavity radiation. It was shown [1], that the maximal efficiency of the operation of Nd-lasers could be achieved while using Q-switches with frustrated total internal reflection (FTIR Q-switches) which possess extremely low losses and high optical durability.
5
Danileiko, Yu K., B. I. Denker, I. Kertész, A. A. Korchagin, N. Kroó, A. G. Musatov, V. V. Osiko, et al. "Q-switching of high power continuous wave and pulsed Nd:YAG lasers." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/cleo_europe.1994.ctuf4.
Abstract:
Nd:YAG laser of 500-W power, continuous wave or pulsed at 10-800 Hz repetition rates with duty cycle from 0.1 up to 0.8 was Q-switched by two different ways. In the first frustrated total internal reflection (FTIR); in the second tunable, small base Fabry-Perot (TFP) was used for switching. In both cases piezoceramies served for the displacement of the switching optical elements. Between 50 and 150 kHz, the measured amplitudephase characteristics have shown resonance at Q ≈ 5, which limit the applicability of these modulators above resonance. Special attention was paid to damp the mechanical resonances up to 200 kHz, using an electro-mechanical model calculation with strong electrical damping parameter. The damped and undamped characteristics are given.
6
Manzo, Maurizio, and Omar Cavazos. "A Wireless Photonic Intraocular Pressure Sensor." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70740.
Abstract:
In this paper, we propose analytical and numerical experiments to investigate the feasibility of a wireless photonic sensor for measuring the intraocular pressure (IOP). The sensing element is a polymeric cavity embedded into a thin layer of biocompatible material integrated to a soft contact lens. The sensor concept is based on the morphology dependent resonance (MDR) phenomenon. Changes in the eye pressure perturb the micro-cavity morphology, leading to a shift in the optical modes. The IOP is measured by monitoring the shift of optical resonances. The sensor-light coupling is made through the evanescent field by using an optical prism. Therefore, the sensor can be powered and monitored wirelessly by using frustrated total internal reflection (FTIR) of a polymeric dielectric cavity. Usually, micro-optical cavities exhibit a very high quality factor Q; thus, sensors based on MDR phenomenon exhibit high resolution. Therefore, by recording tiny variations of IOP is possible to gain more knowledge about the start, comportment, and evolution of glaucoma disease.
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Petrov, Nikolai I. "Frustrated Total Internal Reflection Filter with Heterogeneous Layer." In Frontiers in Optics. Washington, D.C.: OSA, 2019. http://dx.doi.org/10.1364/fio.2019.jtu3a.12.
8
Han, Jefferson Y. "Multi-touch sensing through frustrated total internal reflection." In ACM SIGGRAPH 2005 Sketches. New York, New York, USA: ACM Press, 2005. http://dx.doi.org/10.1145/1187112.1187287.
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Yeliussizov, D., A. Tuyakbayev, and A. Akshabayev. "Multi-touch sensing using frustrated total internal reflection." In 2009 International Conference on Application of Information and Communication Technologies (AICT). IEEE, 2009. http://dx.doi.org/10.1109/icaict.2009.5372574.
10
Hogele, A., and C. Ziolek. "Frustrated Total Internal Reflection Q-Switched Er:YAG and CrEr:YSGG Lasers." In Proceedings of European Meeting on Lasers and Electro-Optics. IEEE, 1996. http://dx.doi.org/10.1109/cleoe.1996.562525.