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Klengel, Sascha. "Design, fabrication and assessment of 2D photonic crystals." Thesis, Imperial College London, 2004. http://hdl.handle.net/10044/1/43395.
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Two dimensional photonic crystals (2D PhCs) in a GaAs/AlGaAs environment were studied experimentally. Emphasis was placed on evaluating the loss characteristics of these structures. Fabrication of 2D PhCs was carried out using a combination of electron beam lithography, reactive ion and electron cyclotron resonance etching techniques. This work was carried out at the Sharp Laboratories of Europe. Excellent control over the more than fifty necessary processing steps was demonstrated and further improvements suggested. An optical laser-based characterization experiment was set up to study the trans-mission, reflection and scattering properties of 2D PhCs embedded in ridge waveguides. These passive structures were designed to operate around 1.55 /xm. Many of the difficulties involved in characterizing structures with dimensions of the order of microns, were overcome to obtain reproducible results. The characterization results obtained in the spectral and Fourier domain demonstrated unambiguously the existence of photonic bandgaps. Fourier analysis was shown to be a particularly useful tool for obtaining physical parameters of the structures, such as propagation loss coefficients and structural information of the sample. A number of loss mechanisms inside photonic crystals were identified. The overall PhC loss was found to be crucially dependent on the etch depth of the holes that constitute the photonic crystal. Work was carried out to show the possibility of producing large fill factor 2D pho-tonic crystals, which could potentially be an ideal environment to embed quantum dots in. Furthermore, patterns with small hole diameters were created, which could be used in conjunction with active organic semi-conducting material. Passive ID microcavities defined by 2D photonic crystals in ridge guides were analysed.
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Hassan, Safaa. "Optical Property Study of 2D Graded Photonic Super-Crystals for Photon Management." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703318/.
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In this dissertation, we study the optical property of 2D graded photonic super-crystals (GPSCs) for photon management. We focused primarily on manipulation and control of light by using the newly discovered GPSCs which present great opportunity for electromagnetic wave control in photonic devices. The GPSC has been used to explore the superior capability of improving the light extraction efficiency of OLEDs. The enhancement of extraction efficiency has been explained in term of destructive interference of surface plasmon resonance and out-coupling of surface plasmon through phase matching provided by GPSC and verified by e-field intensity distributions. A large light extraction efficiency up to 75% into glass substrate has been predicted through simulation. We also study the light trapping enhancement in GPSCs. Broadband, wide incident angle, and polarization independent light trapping enhancement is achieved in silicon solar cells patterned with the GPSCs. In addition, novel 2D GPSCs were fabricated using holographic lithography through the interference lithography by two sets of multiple beams arranged in a cone geometry using a spatial light modulator (SLM). Finally, we also report a fabrication of GPSCs with a super-cell size of 12a×12a by using e-beam lithography. Diffraction pattern from GPSCs reveals unique diffraction properties. In an application aspect, light emitting diode arrays can be replaced by a single light emitting diode shinning onto the diffraction pattern for a uniform fluorescence.
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Lowell, David. "Fabrication and Study of the Optical Properties of 3D Photonic Crystals and 2D Graded Photonic Super-Crystals." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404552/.
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In this dissertation, I am presenting my research on the fabrication and simulation of the optical properties of 3D photonic crystals and 2D graded photonic super-crystals. The 3D photonic crystals were fabricated using holographic lithography with a single, custom-built reflective optical element (ROE) and single exposure from a visible light laser. Fully 3D photonic crystals with 4-fold, 5- fold, and 6-fold symmetries were fabricated using the flexible, 3D printed ROE. In addition, novel 2D graded photonic super-crystals were fabricated using a spatial light modulator (SLM) in a 4f setup for pixel-by-pixel phase engineering. The SLM was used to control the phase and intensity of sets of beams to fabricate the 2D photonic crystals in a single exposure. The 2D photonic crystals integrate super-cell periodicities with 4-fold, 5-fold, and 6-fold symmetries and a graded fill fraction. The simulations of the 2D graded photonic super-crystals show extraordinary properties such as full photonic band gaps and cavity modes with Q-factors of ~106. This research could help in the development of organic light emitting diodes, high-efficiency solar cells, and other devices.
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Tandon, Sheila (Sheila N. ). 1978. "Design and fabrication of a superprism using 2D photonic crystals." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87828.
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Richards, Benjamin Colby. "1D and 2D Photonic Crystal Nanocavities for Semiconductor Cavity QED." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/145275.
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The topic of this dissertation is photonic crystal nanocavities for semiconductor cavity quantum electrodynamics. For the purposes of this study, these nanocavities may be one dimensional (1D) or two dimensional (2D) in design. The 2D devices are active and contain embedded InAs quantum dots (QDs), whereas the 1D devices are passive and contain no active emitters. The 2D photonic crystal nanocavities are fabricated in a slab of GaAs with a single layer of InAs QDs embedded in the slab. When a cavity mode substantially overlaps the QD ensemble, the dots affect the linewidths of the observed modes, leading to broadening of the linewidth at low excitation powers due to absorption and narrowing of the linewidths at high excitation powers due to gain when the QD ensemble absorption is saturated. We observe lasing from a few QDs in such a nanocavity. A technique is discussed with allows us to tune the resonance wavelength of a nanocavity by condensation of an inert gas onto the sample, which is held at cryogenic temperatures. The structural quality at the interfaces of epitaxially grown semiconductor heterostructures is investigated, and a growth instability is discovered which leads to roughness on the bottom of the GaAs slabs. Adjustment of MBE growth parameters leads to the elimination of this roughness, and the result is higher nanocavity quality factors. A number of methods for optimizing the fabrication of nanocavities is presented, which lead to higher quality factors. It is shown that some fundamental limiting factor, not yet fully understood, is preventing high quality factors at wavelengths shorter than 950 nm. Silicon 1D devices without active emitters are investigated by means of a tapered microfiber loop, and high quality factors are observed. This measurement technique is compared to a cross-polarized resonant scattering method. The quality factors observed in the silicon nanocavities are higher than those observed in GaAs, consistent with our observation that quality factors are in general higher at longer wavelengths.
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Morton, Jonathan Andrew Scott. "2D photonic crystals to enhance up-conversion emission for silicon photovoltaics." Thesis, Heriot-Watt University, 2016. http://hdl.handle.net/10399/3110.
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This thesis investigates the application of 2D photonic crystals to enhance the emission of up-conversion layers to improve the efficiency of silicon photovoltaics. Two up-conversion material compositions are of particular interest in this work: erbium doped titanium dioxide (TiO2:Er) and erbium doped yttrium fluoride (YF3:Er). The 2D photonic crystals under investigation are composed of TiO2:Er and air; and YF3:Er and silicon. These nano-structures are investigated using both simulation and experimental methods. Further work in this thesis analyses the properties of the highly conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) for use as a transparent electrode and thin film electrically conductive adhesive for the application of silicon photovoltaics. The design and geometrical parameters for the 2D photonic crystals were optimised through simulations (plane wave expansion and finite-difference time-domain), before the structures were experimentally fabricated and optically characterised. The novel analysis of the refractive index of the prepared up-conversion materials using ellipsometry was a key step in the design of the photonic crystal structures. A maximum photoluminescence enhancement of 3.79 times was observed for the 980 nm emission profile, however this could not be successfully attributed to a photonic crystal effect. The optical, mechanical and electronic properties of PEDOT:PSS were characterised for thin film samples, using novel ellipsometry analysis.
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Hueting, Nikolai Alexander. "Nanophotonic sensors based on 1D and 2D photonic crystals in gallium nitride." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.689692.
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Photonic clystals are an exciting component in the field of nanophotonics. They allow the control, confinement and manipulation of light at the nanometre scale. The ability to fabricate photonic clystals with semiconductor fabrication technology makes them a suitable building block of photonic integrated circuits. Photonic clystals offer sensitivity to surrounding materials and they can enhance light-matter interaction. This has motivated considerable research into their application in the area of chemical and biological sensing. Photonic clystals provide a versatile platform for lab-on-a-chip applications and the prospect of high integration density could benefit cost-sensitive applications such point-of-care diagnostics or environmental sensing. This thesis investigates the feasibility of creating photonic crystal sensors on gallium nitride. The maturity of GaN-based photonic devices, such as LEDs, makes it an ideal platform for lab-on-a-chip applications. Two types of GaN photonic clystals sensors are designed, fabricated and characterised in this work. The first type is a ID grating, which supports guided mode resonances. These are fabricated by electronbeam lithography and dlY etching on GaN membranes and on GaN-on-sapphire. The ability of membrane gratings to sense the refractive index of a liquid that is present at one side of the membrane is verified experimentally. GaN-on-sapphire gratings are presented as a method of enhancing fluorescence emission from molecules placed on the gratings through the guided mode resonances. The second structure analysed is a modified 2D photonic clystal L3 cavity. This novel structure possesses a central hole, which allows the positioning of fluorescent molecules in a region of high electric field density. It is shown by finite difference time domain calculations, that the resonant modes of the cavity significantly enhance the absorption and emission of the molecules. The fabrication and characterisation of those cavities, along with coupling to ridge waveguides, are shown as a first step towards an integrated sensor.
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Maskaly, Karlene Rosera. "Computational study and analysis of structural imperfections in 1D and 2D photonic crystals." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33403.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005.<br>Includes bibliographical references (p. 227-232).<br>Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned ID photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks.<br>(cont.) The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarter-wave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened ID photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on ID photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well.<br>(cont.) Additionally, the problem of acircular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.<br>by Karlene Rosera Maskaly.<br>Ph.D.
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Menezes, Jacson Weber de. "Projetos de camadas fotônicas 2D e fabricação utilizando múltiplas exposições holográficas." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278201.
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Orientador: Lucia Helena Deliesposte Cescato<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin<br>Made available in DSpace on 2018-08-08T11:13:35Z (GMT). No. of bitstreams: 1
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Previous issue date: 2006<br>Resumo: Nesta dissertação foi desenvolvido um novo método de gravação de estruturas bidimensionais em fotorresina, baseado na superposição de três exposições holográficas. Utilizando esta técnica, foi possível gravar estruturas de seção transversal circular. Isso resolve o problema da redução da área do gap fotonico que ocorre com as estruturas cilíndricas de seção transversal elíptica, obtida quando são utilizadas apenas duas exposições. Controlando-se a fase entre a terceira exposição e as duas anteriores é possível também gerar padrões hexagonais com diferentes formas de cilindros, que correspondem aos "átomos" do cristal fotonico, que podem apresentar novas propriedades fotonicas. Para projetar cristais fotonicos que apresentam gap fotonico na região de interesse do espectro eletromagnético, foi utilizado um programa baseado no método dos elementos finitos. Nestes projetos foram consideradas as dimensões e formas que podem ser fabricadas utilizando a técnica de dupla exposição holográfica assim como foi utilizada a aproximação de índice de refração equivalente para levar em conta a espessura da camada fotonica. Utilizando a superposição de duas exposições holográficas, associadas à litografia por corrosão por íon reativo, foram feitas tentativas de fabricação das camadas fotonicas projetadas em três materiais diferentes: silício policristalino, silício amorfo hidrogenado e silício cristalino<br>Abstract: In this work, it was developed a new recording method of the 2D structures in photoresist, based on the superimposition of three holographic expositions. This technique solves the problem of asymmetry of hexagonal structures, arising from the superimposition of only two expositions, which causes a strong reduction of the photonic band gap area. By controlling the phase-shift between the third exposition and the former two exposures, it is possible to generate new hexagonal patterns that can present different properties. In the design of the 2D photonic layers that present Photonic Band Gaps in the near infra-red region of the electromagnetic spectrum, it was used a software based on finite elements method. To consider the thickness of the photonic layer it was used the approach of equivalent refractive index. In the design we take into account the dimensions and shapes that can be fabricated using the technique of holographic lithography associated with RIE (Reactive Ion Etching). For fabrication of the structures we used double holographic exposures followed by RIE lithography in three different materials: poly-silicon, amorphous silicon and crystalline silicon<br>Mestrado<br>Física da Matéria Condensada<br>Mestre em Física
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Ullal, Chaitanya K. (Chaitanya Kishore). "2D and 3D periodic templates through holographic interference lithography : photonic and phononic crystals and biomimetic microlens arrays." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33404.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005.<br>Includes bibliographical references (leaves 121-133).<br>In this thesis a simple technique for controlling structure via holographic interference lithography was established and implemented. Access to various space groups including such important structures as the level set approximations to the Diamond, the Schwartz P structure, the FCC, and the non centrosymmetric Gyroid structures were demonstrated. The ability to make 3D structures over a large area, with low defect densities and periodicities on the sub/i scale opens a whole range of opportunities including such diverse areas as photonic crystals, phononic crystals, drug delivery, microtrusses, tissue scaffolds, microfluidics and colloidal crystallization. A correlation between structure and photonic band gap properties was established by systematically exploring the 11 FCC space groups. This resulted in a technique to search for photonic band gap structures. It was found that a fundamental connectivity caused by simple Fourier elements tended to support gaps. 2-3, 5-6 and 8-9 gaps were opened in the f.c.c lattices. The F-RD and 216 structures were newly shown to have complete band gaps. Two of the three previously established champion photonic crystal structures, viz. the Diamond and the Gyroid presented practical fabrication challenges, approximations to these structures were proposed.<br>(cont.) A scalable P structure and the 3-FCC structure were fabricated by single and multiple exposure techniques. Both negative and positive tone photoresist systems were demonstrated. Line defects were written into the negative tone system using two-photon lithography. The single crystalline, porous nature of the structures was exploited to examine the possibility for their use as hypersonic phononic crystals and microfluidic microlenses. Two dimensional single crystalline patterns were created using interference lithography. Their phononic band structure was probed by Brillioun light scattering to yield a phononic band diagram, which clearly demonstrates the effect of periodicity on the phononic density of states. The ability to control the density of states at these length scales holds the potential for control over thermal properties. The two dimensional structures fabricated in negative photoresist were also tested as microlenses with the integrated pores acting as microfluidic channels. This combination resulted in a structure reminiscent to that of the biological species ophiocoma wendtii.<br>by Chaitanya K. Ullal.<br>Ph.D.
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Anic, Branimir [Verfasser], and W. [Akademischer Betreuer] Dörfler. "The Fourier-Galerkin Method for Band Structure Computations of 2D and 3D Photonic Crystals / Branimir Anic. Betreuer: W. Dörfler." Karlsruhe : KIT-Bibliothek, 2013. http://d-nb.info/1048384896/34.
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Lee, Ko-Hsin. "Investigation and fabrication of 2D photonic crystals structures for light emission and optical modes control at 1. 55 µm." Paris 11, 2008. http://www.theses.fr/2008PA112084.
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Ce travail de thèse porte sur des composants à cristaux photoniques (CP) bidimensionnels réalisés dans des matériaux à base d’InP pour un fonctionnement dans le domaine 1,55 μm. Au sein du CP, la périodicité de la constante diélectrique génère une bande interdite photonique, domaine de fréquence dans lequel la propagation des modes optiques est interdite. L’introduction de défauts dans le CP permet à certains modes optiques localisés d’exister. De telles structures peuvent alors être utilisées comme brique élémentaire d’un circuit intégré photonique. Nous avons étudié des adaptateurs de mode et des lasers monofréquences ainsi que des guides d’onde sur membrane InP. Les CP sont ici un réseau de trous fabriqués à l'aide de la gravure ionique réactive associée à un plasma à couplage inductif. Dans un plasma Cl2/Ar optimisé, nous avons obtenu une profondeur de gravure de 2,9 μm pour des trous de 250 nm diamètre. Nous avons montré que la présence de N2 dans un plasma contenant du chlore renforce la gravure anisotrope et supprime la rugosité des surfaces gravées, et que l’addition de BCl3 permet d’augmenter la verticalité des trous. Le plasma BCl3/N2 a permis d’obtenir les meilleurs profils et états de surface et une profondeur gravée de 1 μm. Plusieurs géométries d’adaptateurs de mode à CP. Ont été étudiées et leurs spectres de transmission ainsi que la divergence du mode émergent ont été caractérisés et comparés avec les résultats de simulation. La meilleure géométrie conduit à une amélioration de l’efficacité de transmission d’un facteur 4. Les guides W1 sur membrane InP présentent des pertes de propagation de 25 dB/cm pour des fréquences situées sous la ligne de lumière<br>This PhD work focuses on two-dimensional photonic crystals (PhC) devices based on InP materials for application around 1. 55 µm wavelength. PhC is a periodic structure in dielectric constant and is characterized by photonic band gap, a frequency domain in which the light propagation is inhibited for certain directions. Introducing defects in the periodicity offers another manner for light guiding and photon localization, which may provide a platform for photonic integrated circuits. The investigated devices include PhC taper waveguides and multiple-constricted-waveguide lasers on InP substrate, and PhC channel defect waveguides on InP suspended membrane. The perforated PhC structures are realized using reactive ion etching technique associated with inductive coupled plasma. A Cl2/Ar plasma has been optimized and demonstrated an etch depth of 1. 9~2. 9 µm for 110~250 nm-diameter holes. We have demonstrated that the addition of N2 into chlorine-containing plasmas can enhance the anisotropic etching and suppress the etched surfaces roughness. In addition, we have shown that adding BCl3 augments the feature verticality. Extremely smooth etched sidewall surfaces are obtained when the etching is performed under the BCl3/N2 plasma; in which an etch depth of 1 µm can be achieved. Several contour geometries of PhC tapers are studied and their transmission spectra and beam divergences are measured and compared with the simulation results. The transmission efficiency can be enhanced by a factor of 4 owing to the proper taper design. As for suspended membrane, a propagation loss of 25 dB/cm has been obtained for W1 PhC waveguide while operating below the air-light line
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Zhu, Rui. "Integrated nano-optomechanics in photonic crystal." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS258/document.
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Les oscillateurs de référence de haute pureté sont actuellement utilisés dans un grand nombre d’applications allant du contrôle de fréquence aux horloges pour les radars, les GPS et l’espace... Les tendances actuelles dans ce domaine requièrent des architectures miniaturisées avec la génération de signaux directement dans la gamme de fréquences d’intérêt, autour de quelques GHz. Récemment, de nouvelles architectures basées sur les principes de l’optomécanique ont vu le jour dans ce but. De tels oscillateurs optomécanique génèrent non seulement des signaux hyperfréquences directement dans la gamme de fréquences GHz avec éventuellement un faible bruit de phase, mais permettent également un degré élevé d'intégration sur puce. Ce travail de thèse s'inscrit dans cette démarche. L’oscillateur optomécanique étudié se compose de cavités à cristaux photoniques suspendues couplées à des guides d’ondes silicium sur isolant intégrés dans une architecture tridimensionnelle. Ces cavités abritent des modes optiques fortement confinés autour de 1550nm et des modes mécaniques dans le GHz. De plus, ces structures présentent un recouvrement spatial entre phonon et photon élevé. Il en résulte un couplage optomécanique amélioré. Cette force de couplage optomécanique améliorée est ici sondée optiquement sur des structures à cristaux photoniques de conception optimisée. Ces cavités sont réalisées dans des matériaux semi-conducteurs III-V dont la piézoélectricité nous permet d'intégrer des outils supplémentaires pour sonder et contrôler les vibrations mécaniques via un pilotage capacitif, piézoélectrique ou acoustique. Ce contrôle total des modes mécaniques et de l’interaction optomécanique ouvre la voie à la mise en œuvre de circuits intégrés pour le verrouillage par injection et des boucles de rétroaction permettant de réduire le bruit de phase de l’oscillateur<br>High purity reference oscillators are currently used in a wide variety of frequency control and timing applications including radar, GPS, space... Current trends in such fields call for miniaturized architectures with direct signal generation in the frequency range of interest, around few GHz. Recently, novel optomechanically-enhanced architectures have emerged with this purpose. Such optomechanically-driven oscillators not only generate microwave signals directly in the GHz frequency range with possibly low phase noise but also are amenable to a high degree of integration on single chip settings. This PhD work falls within this scope. The optomechanically-driven oscillator under study consists of suspended photonic crystal cavities coupled to integrated silicon-on-insulator waveguides in a three-dimensional architecture. These cavities harbor highly-confined optical modes around 1,55 µm and mechanical modes in the GHz and most importantly, feature a high phonon-photon spatial overlap, all resulting in an enhanced optomechanical coupling. This enhanced optomechanical coupling strength is here probed optically on photonic crystal structures with optimized design. These cavities are hosted in III-V semiconductor materials whose piezoelectricity enable us to integrate additional tools for probing and controlling mechanical vibrations via capacitive, piezoelectric or acoustic driving. This full control over the mechanical modes and optomechanical interaction, paves the way towards the implementation of integrated injection locking circuits of feedback loops for reducing the phase noise of the oscillator
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Blumenthal, Sarah [Verfasser]. "MBE-grown cubic GaN QDs integrated into 2D photonic crystal membranes / Sarah Blumenthal." Paderborn : Universitätsbibliothek, 2019. http://d-nb.info/1182422381/34.
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Vo, Thanh Phong. "Optical near-field characterization of Slow-Bloch Mode based photonic crystal devices." Phd thesis, Ecole Centrale de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00758323.
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2D-Photonic crystal (PC) structures have enabled the fabrication of a wide variety of nanophotonic components. In perfect PCs, the exploitation of the enhanced local density of states at critical points of the band diagram has attracted considerable attention. Near these points, where the group velocity vanished, low curvature flat bands give rise to delocalized and stationary optical slow Bloch modes (or slow light modes). Properties of slow light make them good candidates to enhance Purcell or various non-linear effects or to design low-threshold lasers. Among these modes, slow Bloch modes (SBMs) emitting in the vertical direction, i.e. located at the Γ- point of the Brillouin zone are particularly interesting for integrating 2D PC architectures with free space optics. In particular, some SBMs proved to be suitable for achieving strong vertical emission with peculiar polarization properties. Other promising applications concern disorder: by introducing a controlled randomness into the PC structure, it is possible to induce a transition from slow Bloch mode (in ordered PC) to Anderson's localization (in disordered PC) as a function of disorder degree. In this PhD dissertation, Slow Bloch modes have been studied and characterized by the means of Near-field Scanning Optical microscopy (NSOM). We particularly focused on Slow Bloch laser mode at Γ- point of a honeycomb 2DPC. This NSOM technique enables to visualize the evanescent component of the mode with a spatial resolution below the diffraction limit. In this work, we showed that the far-field and the near-field image of the mode at the 2D-PC surface are different and that near-field results yield a better insight in the real mode structure inside the PC slab in agreement with theoretical prediction. The importance of the probe selection (bare silica, metallized tip and bow-tie aperture nanoantenna) for studying III-V photonic crystal structures was also demonstrated. Besides intensity measurement of the electromagnetic field, the polarization of the electric field has been measured at the nanoscale for the first time by using a bow-tie nano-antenna probe. These results enable the unambiguous identification of the modes with the 3D-FDTD simulations.In this work is also reported the first observation of two-dimensional localization of light in two types of 2D random photonic crystal lasers, where Slow Bloch Mode (SBM) is scattered by artificial structural randomness in triangular PCs. The structural randomness is introduced whether by nanometer displacements in the positions of lattice elements (air holes), whether by variation of the hole diameters. The direct near-field imaging of the lasing mode by use of NSOM for the first time, allowed us to observe the transition of the extended planar SBM to be Anderson localized.
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Szendrei-Temesi, Katalin [Verfasser], and Bettina [Akademischer Betreuer] Lotsch. "2D nanosheets as functional building blocks for 1D photonic crystal sensors / Katalin Szendrei-Temesi ; Betreuer: Bettina Lotsch." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1189584638/34.
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O'Regan, Bryan J. "Resonantly enhanced thermal emitters based on nanophotonic structures." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7801.
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The manipulation of photons, especially the control of spontaneous emission, has become a core area of photonics research in the 21st century. One of the key challenges is the control of the broadband emission profile of thermal emitters. Recently, attention has focused on resonant nanophotonic structures to control the thermal emission with most of the work concentrating on the mid-infrared wavelength range and/or based on metallic nanostructures. However, the realisation of a high temperature, single wavelength, narrowband and efficient thermal source, remains a challenge. In this project, four individual nanophotonic resonant structures are presented for the control of thermal emission, all operating in the near-infrared (≈ 1.5 μm) wavelength range. The work is split over two different emission materials; gold and doped silicon. While I present two successful designs of narrowband thermal emitters from gold, the main backbone of the research is concentrated on doped silicon as the emission material. By combining the weak broadband absorption of doped silicon with a photonic crystal resonator, resonantly enhanced narrowband absorption is achieved. Using Kirchhoff's law of thermal radiation which equates the absorptivity and emissivity, narrowband absorption leads to narrowband emission, which is the underlying principle used throughout the work presented in this thesis to achieve narrowband thermal emission. One common oversight in many of the presented thermal emitter designs is the angular emission dependence, i.e. how the emission wavelength behaves away from surface normal. Typically, since the majority of the devices are based on periodic structures, the resonant emission wavelength changes with emission angle, which is not ideal. Here, the angular sensitivity is considered and addressed, by constructing a device that is based on localised confined resonances and not on propagating resonances, it is possible to achieve a truly monochromatic source i.e. one with the same emission wavelength in all directions, all the way up to an angle of 90°. Finally, the devices presented here demonstrate that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission away from the resonant wavelength.
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Divliansky, Ivan Borissov. "Fabrication of 2D and 3D photonic crystals and template." 2004. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-488/index.html.
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Peng, Siying. "2D and 3D Photonic Crystals: Synthesis, Characterization and Topological Phenomenon." Thesis, 2018. https://thesis.library.caltech.edu/10427/13/SiyingPeng_thesis_09122017.pdf.
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<p>Topological photonics has become an increasingly popular research topic in the field of nanophotonics in recent years. Topological phases of light provide opportunities to manipulate light propagation efficiently at the nanoscale volume. Performance of conventional optical elements are limited by back-reflection and bending losses, which hinder their prospect of large scale integration. Topological protection enables unidirectional excitation of edge states or surface states without leaking into the bulk, as well as suppression of scattering when encountering defects and corners. With such advantages, topological photonic elements may surpass conventional photonic
design for future generations of ultra-compact efficient computing, imaging, and sensing applications. Due to limitations of fabrication and characterization techniques, previously experimental efforts on topological photonics have been carried out with 2D micron-scale optical design or at the microwave wavelength.</p>
<p>This thesis contributes to the experimental development of topological photonics in two aspects: first, how to fabricate and characterize 3D photonic crystals and therefore extend topological protection into the 3D (Chapters 2-3); and second, how to realize nanoscale topological protection in the visible frequencies (chapters 4-6). Specifically, Chapter 2 reports fabrication of 3D single gyroid structures composed of a-Si and FTIR characterization of a photonic bandgap at the mid-infrared wavelength. This is the foundation to investigate more complex morphologies to introduce topologically nontrivial photonic states. Chapter 3 describe properties of
double gyroid photonic crystals, followed by angle resolved characterization method in the mid-infrared. Double gyroid photonic crystals can be designed to possess quadratic degeneracy points, Weyl points, and line nodes. Since Weyl points have non-zero Chern numbers, surface states are topologically protected in double gyroid photonic crystals with parity breaking symmetry. The angle resolved characterization method could be utilize to resolve both Weyl points and surface states. Chapter 4 depicts design, fabrication, and characterization of Dirac-like surface plasmon dispersions in metallic nano-pillars. Chapter 5 presents experimental investigation
of coupled silicon Mie resonators, which is the first step towards topological design based on inter-lattice sites coupling in the next chapter. Chapter 6 details photonic bandstructure from angle-resolved cathodoluminescence measurements. We analyze bandstructures collected from the bulk of trivially and topologically gapped lattices, as well as zigzag and arm-chaired edges of domain boundaries. Chapter 7 outlines a method to optically enhance dissociation of hydrazine molecules using ultraviolet plasmons, and attempts to use this method for low temperature GaN growth.</p>
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Du, Cheng-Han, and 杜宬翰. "The Study of 2D Photonic Crystals Fabricated by Holographic Polymer-Dispersed Liquid Crystal Technique." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/01692274757415450101.
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碩士<br>國立暨南國際大學<br>光電科技碩士學位學程在職專班<br>104<br>Abstract
In the paper, we will discuss the 2D photonic crystals fabricated by holographic polymer-dispersed liquid crystal technique. A dispersion angle of 68° is observed within continuous spectrum dispersion from 360 to 700 nm at an incident angle of 20° using white light as a probe beam. By changing the angle between the sample normal and the probe beam, the dispersed spectrum can be tuned at a spectral resolution of 3.6 nm per degree.
This two-dimensional photonic crystals with good optical properties, its manufacturing method is simple, low cost, and can be applied in spectroscopic analysis.
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Chuang, Lu-Meng. "Fabrication and Optical Properties of 2D Photonic Crystals of CdSe Pillars." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2907200400320200.
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Chuang, Lu-Meng, and 莊祿萌. "Fabrication and Optical Properties of 2D Photonic Crystals of CdSe Pillars." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/92366742371415431272.
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碩士<br>國立臺灣大學<br>物理研究所<br>92<br>This thesis concerns with the fabrication and optical properties of two-dimensional photonic crystals of CdSe pillars. The combination of electron beam lithography and electrochemistry deposition methods has been employed to fabricate sub-micrometer scale CdSe pillars. The optical properties of CdSe pillars are characterized by micro- photoluminescence (µ-PL).
The formation of the wurtzite crystal structure of CdSe has been confirmed by Raman spectra. Quite interestingly, in the study on optical properties, we found that the intensity of micro-photoluminescence (µ-PL) can be greatly enhanced at a particular structure of photonic crystals. This peculiar phenomenon can be explained quite well in terms of the effects of photonic crystals. PCs can provide a photonic band gap in the lateral dimensions so that the emission of CdSe pillars can not propagate in the lateral plane and can only propagate upward with respect to the photonic crystal. Thus, the detected PL intensity normal to the lateral plane is enhanced.
The combination of electron beam lithography and electrochemical deposition technique provides a simple and low cost method to grow sub-micro meter scales structures. We therefore demonstrate an alternative method to fabricate high efficiency of luminescent optical device.
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Tsao, Ming Feng, and 曹銘峰. "A Study of Negative Refraction and Focusing Effects in 2D Photonic Crystals." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/12175212194874357821.
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Shih, Pi-Kuei, and 石璧魁. "Measurement and Analysis of Defect Modes in 2D and 3D GaAs Photonic Crystals." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/36596458046110734904.
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碩士<br>臺灣大學<br>光電工程學研究所<br>95<br>Photonic crystals are materials with periodical dielectric constants. The band gap occurs according to the destructive interference, where certain wavelengths are not allowed to pass through. The light at those frequencies can not find a real propagation constant and thus will be scattered. Besides perfect photonic crystals, we are more interested in those photonic crystals with defects because those modes resulted from the defects are spatially confined in comparison with those non-defect modes. In other words, we can control the behavior of the defect modes by adjusting the fine structures in the photonic crystal. This is a very interesting phenomenon. An example of this is the photonic crystal waveguide, where lights will propagate along the direction we design.
By developing automatic measurement techniques, we can acquire correct and stable information efficiently. For two-dimensional slab structures, we focus on the resonant cavities formed by the photonic crystals and expect to observe the resonant modes and the field distribution. With the assistance of the motorized stage, we could stably scan the spatial light intensity distribution and then observe the spectrum and the field intensity distribution of the defect modes. With the spectrum and the field distribution of the defect modes, we could understand more about the effects of the resonator. In the structure we designed in this work, we successfully find two resonant modes around 952nm and 960nm on the spectrum by observing the transmitted and the scattered spectrum. On the other hand, owing to the difficulty in constructing the point-defect by the auto-cloning method in three-dimensional checkerboard structures, we designed line-defects instead and then observed the effect from them. We observed the spectra and the spatial distribution of the defect modes. But we can’t find the obvious difference in spatial field distribution between two defect structures which have different sizes. It’s probably limited by the detection resolution and stability.
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Yun-HsuanShen and 沈運宣. "Enhanced Light Extraction Efficiency from Organic Light‐Emitting Diodes by Inserting 2D Photonic Crystals with Archimedean Tilings." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/56784282104112617208.
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碩士<br>國立成功大學<br>製造資訊與系統研究所碩博士班<br>101<br>Organic light-emitting diode(OLED) is considered as a critical component for next generation displays due to its light weight, thin thickness, wider viewing angles and low operational voltage. The OLED displays have been actively investigated in recent years on account of their potential applications in flat panel displays and flexible displays. A typical OLED is composed of a layer of organic materials situated between the anode and cathode, all deposited on a substrate. However, because of the high refractive index of the anode ITO layer(n=1.8), the light extraction efficiency of a conventional OLED is still limited to be as low as 20%, which is one of the most important issues for practical device applications. The low efficiency arises from that most of the emitted light is confined inside the device due to the total internal reflection(TIR) at the interfaces of the layers.
Photonic crystals(PhCs) are artificial multi-dimensional periodic structures with periodic modulation of the refractive index. Suitably designed, PhCs have the ability to control the propagation of light. The PhCs have both guide and radiation modes. The guide mode allows the lights to transmit internally. In contrast, the radiation mode refers to the phenomena in which the lights are not guided to transmit internally. Set the incident light in the radiation modes, then it would not propagate along the wave guide internally. Instead, the lights radiate and escape from the wave guide. By taking advantages of this feature, we can therefore enhance the efficiency of light extraction by embedding photonic crystals in the multiple structures, such as LED and OLED.
To improve light extraction from organic light-emitting diodes(OLED), we present a photonic crystal with 12-fold symmetry Archimedean A7 lattice into the glass substrate of an OLED. The two-dimensional SiO2/SiNx photonic crystal layer converts the guided waves in the high-refractive-index indium-tin-oxide(ITO)/organic layers into radiation waves. By using the plane wave expansion method(PWEM), we design the structural parameters of the photonic crystal pattern and the finite-difference time-domain(FDTD) method to simulate the light extraction from the PhC-OLED.
There are two parts of the simulation results, from the electric field and transmission, we can observe the lights transmit into glass layer form the organic emitting layer because of the Archimedean A7 lattice with higher order symmetry and density of states in the radiation mode; we compare the enhancement of light extractions by integrating the far-field projection over the viewing angles and different etching depths, it follows that this design would contribute to not only making OLED lights brighter and more concentrated but also consuming less process time and cost in comparison with conventional PhC-OLED.
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Rong, Qiu Yi, and 邱奕榮. "The band structure in 2D hexagonal pipe photonic crystal." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/58491984925513067779.
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碩士<br>國防大學中正理工學院<br>應用物理研究所<br>94<br>In this paper, the photonic crystal with two-dimensional hexagonal pipes structures is investigated. This photonic crystal includes the special case that with the two-dimensional hexagonal cylinders structure. In this investigation, we know that the energy band of the hexagonal cylinders structure photonic crystal will shift to lower frequency when the filling rate and dielectric coefficient increasing. And the width of complete gap will increase then decreasing. The structure of the Complete Gap is not effected by the alteration of dielectric coefficient. It would effect the width of band gap and frequencies when the dielectric coefficient been changed. In the different materials of hexagonal cylinders structure photonic crystal, the energy band gaps shift to lower frequencies when the dielectric coefficient increasing. When the cylinders radii are equal, the conditions of maximum gap been found. And in the hexagonal pipe structure photonic crystals, when the fitting materials are changed from cylinders to pipes, the energy band shift to higher frequencies just as the filling rate is decreasing. In this condition, it would be Complete Gape that it should not be Complete Gape. The Complete Gap of the hexagonal pipes structure photonic crystals would be found by this way.
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Wu, Sung-Ping, and 吳松屏. "Design and Characterization of 2D and 3D Photonic Crystal Fibers." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/90203901252675725944.
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碩士<br>國立中山大學<br>材料科學研究所<br>94<br>Because of the fast growing in communications, the quality of signal transmission in optical fiber becomes very important. Concurrently, photonic crystal fiber (PCF) consisting of a central defect region surrounded by multiple air holes is attracting much attention in recent years because of its unique properties, such as full photonic bandgaps, wideband, dispersion, endlessly single mode and birefringence, etc.
This thesis is mainly focused on the development of the photonic band structures and propagation properties of PCF. And we propose a novel ideal about 3-D PCF, which can be fabricated using the laser heated pedestal growth (LHPG) method.
In the thesis, we study the optical properties of 2-D and 3-D PCFs made by Pyrex using the software RSoft. From the result of simulation, the 2-D out-of-plane bandgaps for a hexagonal close packed structure appear between the air filling fraction range from 0.30 to 0.88 for the incident light of wavelength range from 0.7 to 1
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Kuei-Jen, Lee. "2D CMOS Photonic Crystal for Beam Polarization and Beam Modulation in the Parabolic Photonic Crystal Structure of Firefly's Eyes." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0009-2401200703235200.
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Lee, Kuei-Jen, and 李桂仁. "2D CMOS Photonic Crystal for Beam Polarization and Beam Modulation in the Parabolic Photonic Crystal Structure of Firefly''s Eyes." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64674995059223271165.
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博士<br>元智大學<br>電機工程學系<br>95<br>In recent years, it is very popular for applying photonic crystal (PC) structure to design optical components. In this thesis, we designed a two-dimensional photonic crystal optical modulator by using the general complementary metal-oxide semiconductor (CMOS) integrated circuit (IC) processing parameters. Chips of optical polarizer have been successfully designed by adopting the technologies of semiconductor fabrication. This study extends the fabrication of ICs to that of PCs and makes the shrinkage of device dimension from the order of centimeter to that of micrometer possible. Moreover, it is achievable to use the IC processes for the PC production.
As to the research for the optical properties of biological eyes, this is the first study to investigate the firefly’s eyes by replacing its crystalline cone with the periodic indices of refraction and constructing a configuration of 190 parabolic layers. It was treated as a one-dimensional periodic photonic crystal on the optical axis. By using the principles of geometric optics, we simulated its dioptric portion and realized its behavior of the visual output according to the optical ray-tracing. We further applied the transfer matrix to observe its transmission and found that there exists the filtering capability on its optical axis. On the contrary, there is no such filtering effect but with the capability of receiving other visible light for the retinal cell nuclei around the axis. It might be deduced that all the retinal cell nuclei of the firefly’s eyes can receive the different range of light wave. Besides, we also discussed the focusing efficiency of the firefly’s eyes. Based on the input of collimating light, the efficiency of an overlapped image focused by a compound eye is higher than that of a parallel image by nine hundred times. Furthermore, there is radial gradient index existing by using such a configuration proposed in this thesis.
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Li, Ming-Chun, and 李明駿. "The Study and Fabrication of 2D amd Modified 1D Photonic Crystal Microcavity." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/93626841764453226108.
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碩士<br>國立中山大學<br>光電工程研究所<br>93<br>In this thesis, we fabricated the 2D photonic crystal and modified 1D photonic crystal microcavity on the InGaAs/GaAs substrate by E-beam lithography. The wafer are grown by molecular beam epitaxy (MBE) on GaAs substrate. The active layer consists of six InGaAs quantum wells at 1050nm emission wavelength.
For the 1D photonic crystal microcavity (DBR laser),we changed the cavity shape and length to match the mode of light in the cavity. It can increase the reflectivity of the laser. In our simulations, we scanned different cavity length and found the corresponding data. We designed two and three pairs of DBRs formed on the edge of laser cavity, respectively. The cavity length is 121µm and the mirror width is 230nm and the air gap is 263nm.
For the 2D photonic crystal (2DPC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 742nm and 304nm, respectively. The TE modes photonic band gap of this structure are corresponding to wavelength range in 1026nm ~ 1089nm. We placed single defect in the 2DPCs to form 2DPC microcavities and the corresponding defect modes are 1051.58nm、1053.39nm and 1054.87nm. In addition, we reduced the air columns around the cavity and simulated the photonic bandgap and fabricated the devices by E-beam lithography and deep dry etching process.
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Nicholaou, Costa. "Improving the Detection Limit of Planar 2D Photonic Crystal Slab Refractive Index Sensors." Thesis, 2013. http://hdl.handle.net/1807/43273.
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Two dimensional photonic crystal slabs are studied theoretically and experimentally for the application of refractive index sensing with a focus on increasing both quality factor and sensitivity simultaneously. An overview of simulation and experimental techniques, along with fabrication protocols used is given. Through the use of new wafer architectures which allow for an air substrate, sensitivity is enhanced in some cases by more than a factor of 2 from our previous studies. Combining this with a novel lattice proposed which greatly reduces fabrication tolerances, experimental quality factors above 10,500 are achieved while maintaining an experimental sensitivity of above 800 nm/RIU. The effects of a finite photonic crystal slab are studied through the group velocity of guided mode resonances, with an emphasis on zero-group velocity. Future applications of the designs proposed are discussed.
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Wei, Liu Tzu, and 劉子維. "The Optical Characteristics Research of GaN-based 2D Photonic Crystal Surface Emitting Lasers." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/87524898389655167073.
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碩士<br>國立交通大學<br>光電工程系所<br>96<br>In this thesis, we investigated the optical characteristics and distributed feedback theory of GaN-based 2D photonic crystal surface emitting lasers (PCSELs). According to the theory, the lasing behavior in the photonic crystal grating structure could only happen as the Bragg condition is satisfied. Therefore, the lattice constant is determined range from 190 to 300 nm considering PL peak centered at a wavelength of 425nm. The lasing wavelength is 395nm to 425nm for different device. We take the lattice constant 254nm for example, which with a linewidth of about 1.9 Å at room temperature. The pumping threshold energy density was estimated to be 2.8 mJ/cm2. Moreover, the degree of polarization and divergent angle of the laser emission is about 53% and smaller than 10o, respectively. The characteristic temperature is about 148K. We use plane wave expansion method (PWEM) to simulate the TE band diagram. All normalized frequency of investigated PC lasing wavelength can correspond to three band-edge frequencies (Γ1, K2, M3), which indicates the lasing action can only occur at specific band-edges. Polarization states confirm the existence of lasing modes at different band-edge (Γ1, K2, M3). The coupling coefficient at different band-edge (Γ1, K2, M3) can be obtained based on 2D couple wave model. The threshold gain at Γ1 is the lowest which corresponds to the highest coupling coefficient while the threshold gain at K3 is the highest which corresponds to the lowest coupling coefficient. Overall, the promising features of GaN-based PCSELs make it become the highly potential optoelectronic device in high power blue-violet emitter applications.
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Chiang, Chih-yun, and 江之昀. "The Study of 2D Photonic Crystal Guided-Mode Resonance Waveguide by Using Nanosphere." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/92924730314400756112.
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碩士<br>國立中央大學<br>光電科學研究所<br>99<br>This study fabricated a nano-structure in the shape of a hexagonal-lattice grating through the arrangement of nanospheres. This structure offers a number of advantages, including easy fabrication, excellent coverage, and structural regularity. Such structures have been applied to the development of biosensors and color filter. This study proposes that a single layer sedimentation of nanospheres be used as an easily fabricated alternative to photolithography .
This study observed the resonance behavior of the proposed two dimensional guided-mode resonant through rigorous coupled-wave analysis (RCWA). Incident wavelength, grating thickness, and grating fill ratio were selected as the parameters for simulations. Using period = 780 nm as an example, when the fill ratio ≧ 0.6, resonance was achieved. By broadening the angular tolerance of the self-suspended subwavelength grating, this study fabricated a three two-dimensional guided-mode resonant filter.
The measurement results of wavelength and full width half maximum (FWHM) were λ(nm):Δλ(nm), respectively. Sample A: 1106:17, 1142: 22, 1368:30; Sample B: 1155:27, 1235:40, 1365:24; Sample C: 1276:102, 1624:151. This study demonstrated that Sample C in multi-mode showed broadening of angular tolerance at an oblique angle of incidence.
This study demonstrated that two-dimensional guided-mode resonance filters can be fabricated through the use of nanospheres, which can simplify the process of fabricating such devices.
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yu, sheng chang, and 張宇生. "The 2D Photonic Crystal Band-Gap with Various Row Numbers in Far-infrared." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/75547494841070717382.
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碩士<br>中華大學<br>電機工程學系碩士班<br>93<br>The idea of this paper is to probe the band-gap behavior of two-dimension photonic crystal with various row numbers in far-infrared range. The simulation result shows that the transmission was not decreased as the row number increasing directly, but had a certain trend. The 2-D photonic crystal material criteria in this experiment were easy to obtain, larger index and easy fabrications. Silicon-air periodic structure was the best choice. A tunable CO2 laser with the wavelength range of 9.2 m to 10.6 m was applied for the measurement light source for the purpose of large size characteristics for the 2-D photonic crystal. The experiment results consisted with the ones of simulation. The band-gap characteristic was observed as the row number over 4. In this work, the sample fabrication and the measurement technique were built, which showed the great potential for further study of photonic crystal in IR or visible range.
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Shiue, Chau-Wei, and 薛超瑋. "The Study and Fabrication of 2D Photonic Crystal Microcavity and LC-DFB laser." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/88976695564899650888.
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碩士<br>國立中山大學<br>光電工程研究所<br>94<br>In this thesis, we fabricated the 2D photonic crystal microcavity and laterally coupled distributed feedback laser on InGaAs/InAlGaAs wafers by E-beam lithography. We also fabricated the 2D photonic crystal microcavity on the InGaAs/GaAs substrate at 980nm emission wavelength. The wafer are grown by molecular beam epitaxy (MBE).
For the laterally coupled distributed feedback laser (LC-DFB laser) , we changed the grating shape and length to form proper grating, and it will make constructive diffraction and coupling. We design the mirror width is 180.55nm and the air gap is 541.65nm.
For the 2D photonic crystal (2DPC) microcavity, a triangular array of air columns was adopted. The lattice constant and air columns radius are 1139nm and 456nm, respectively. The TE modes photonic band gap of this structure are corresponding to wavelength range in 1522.72nm~1617.89nm. We placed single defect in the 2DPCs to form 2DPC microcavities and the corresponding defect modes are 1549.23nm and 1550.08nm. We have simulated the photonic bandgap and fabricated the devices by E-beam lithography and deep dry etching process. Also, we can use the same method to fabricate 980nm photonic crystal.
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Liu, Ting-Chun, and 劉亭均. "The Study of lasing behavior in GaN-based 2D Photonic Crystal Surface Emitting Lasers." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/44186236971352286247.
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碩士<br>國立交通大學<br>光電工程系所<br>97<br>In this thesis, we investigated the different lasing behavior of GaN-based 2D photonic crystal surface emitting lasers (PCSELs) according to different photonic crystal (PhCs) lattice constant. Based on the Bragg theory for PhCs period structure, the lasing behavior could only happen when the Bragg condition is satisfied. Therefore, we simulated the band diagram of TE mode by plane wave expansion method, designed the PhCs lattice constant ranging from 190 to 230 nm, and fabricated the PhCs period structure on our novel GaN-based resonance cavity light emitting diode. By the excitation of pulse laser, the PhCs lasing action is achieved under the optical pumping system. Normalized frequency of investigated PCSELs lasing wavelength can be correspond to three band-edge frequencies (Γ1, K2, M3), which indicates the lasing action can only occur at specific band-edges. We also measured the angle-resolved μ-PL diagrams of different lasing modes. The results further confirmed the lasing modes existed at different band-edge (Γ1, K2, M3) and emitted different lasing angles by mapping the diffraction patterns of band structures and the Bragg theory. From our experiment results, the three band-edge frequencies including Γ1, K2, and M3 has different emission angles corresponding to the normal direction (0˚, 29˚, 59.5˚), respectively. Moreover, the far field pattern of Γ1 mode we observed is symmetric due to the PhCs’ symmetric pattern structure. Besides, the degree of polarizations and divergence angles of Γ1, K2, and M3 modes laser are about (33%, 35%, 55%) and (1.2˚, 2.5˚, 2.2˚), respectively. Overall, according to the superiority features of GaN-based PCSELs, the structure can be applied in the visible and UV laser and become the highly potential optoelectronic device in high power emitter applications.
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Weng, Peng-Hsiang, and 翁鵬翔. "The Study of Threshold gain in GaN-Based 2D Photonic Crystal Surface Emitting Lasers." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/09402779089797808783.
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碩士<br>國立交通大學<br>光電工程學系<br>98<br>In this thesis, we investigated the different lasing behaviors of threshold gain in GaN-based 2D photonic crystal surface emitting lasers (PCSELs) according to Multiple Scattering Method (MSM). Based on the Bragg diffraction theory for PCs period structure, the lasing behavior could only be happened when the Bragg condition is satisfied. Our studies are especially focused on the band edge at Γ2 point because of the characteristic of photonic crystal surface emitting. In our study, we divide research into three parts to study the different effect of structure on PCSELs. At first, we change the number of shell for PCSELs that would affect the threshold gain and normalized frequency. When the number of shell is over 20, the influence of photonic crystal will decrease. Secondly, we modify the filling factor of photonic crystal to optimize the threshold gain parameter for PCSELs. The four Γ2 point band-edge of PCSELs have different lasing threshold gain distribution. Finally, we consider the boundary condition for our PCSELs. The circle boundary has the lower threshold gain than the usual hexagonal boundary. As a result, we designed the PCs lattice constant about 190nm for Γ2 point lasing, and successfully fabricated the PCs structure on our novel GaN-based resonance cavity light emitting diode.
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Suh, Myoung-Gyun. "Theoretical Analysis on the Liquid Crystal Infiltrated Tunable 2D Photonic Crystal Laser using Finite-Difference Time-Domain Method." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2001200612060800.
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Suh, Myoung-Gyun, and 徐明均. "Theoretical Analysis on the Liquid Crystal Infiltrated Tunable 2D Photonic Crystal Laser using Finite-Difference Time-Domain Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/33260491544218447513.
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碩士<br>國立臺灣大學<br>物理研究所<br>94<br>In recent years, with growing interests to Photonic Crystals (PhCs) and their applications, many researchers have studied PhCs. 2-Dimensional PhC laser is one of the interesting research topics due to its strong light confinement in a small wavelength-scale volume.
Liquid Crystal (LC) infiltrated 2D PhC laser has also been investigated for the laser wavelength tuning, yet its theoretical study seems insufficient. Thus, in this research, we developed 3D Finite-Difference Time-Domain (FDTD) program which can simulate the light propagation in LCs, and analyzed the characteristics of LC infiltrated 2D PhC laser.
In several characteristic PhC structures, the lasing wavelength shift of a single mode, the degeneracy splitting, the lasing mode change and the quality factor (Q-factor) change are found as the arrangement of LCs changes. Moreover, by properly designing the defect, we can expect the intrinsic polarization of the lasing mode.
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Mack, Patrick [Verfasser]. "2D H-polarized auxiliary basis functions for the extension of the photonic Wannier function expansion for photonic crystal circuitry / von Patrick Mack." 2011. http://d-nb.info/1012674371/34.
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Yan, Cai-Xia, and 晏彩霞. "Fabrication of 2D Photonic Crystal Slab Waveguides using Near-Field Phase-Shifting Contact Lithography and Interference Lithography." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/19848773817601451034.
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碩士<br>國立臺灣大學<br>電機工程學研究所<br>95<br>This thesis describes an approach to fabricate a 2-dimensioinal photonic crystal waveguide by combining near-field phase-shifting contact lithography and interference lithography.
The elastomeric phase mask is fabricated by casting and curing the prepolymer of PDMS (Polydimethylsiloxane) against photolithographically patterned lines of photoresist on a silicon substrate. We then expose the UV light through the elastomeric phase mask onto the photoresist to perform photolithography in the near field of the mask for fabricating the 2-dimensional photonic crystal waveguides. These waveguiding patterns are transferred to the underlying chromium layer by chemical wet etching. Critical dimensions as small as 100 nm can be fabricated by this method[1]. Then photoresist is spun onto the substrate which contains the chromium lines and exposed to 351 nm wavelength of argon ion laser to perform the interference lithography. Square or triangular lattice of 2D photoresist patterns can be achieved by simply rotating the substrate to specific angle to perform multiple exposures. These photoresist patterns are transferred to the deposited chromium layer by liftoff process. Silicon on insulator (SOI) is chosen to be waveguiding material because its index contrast is high enough to support a guided Bloch mode in photonic crystal waveguides. The desired patterns were transferred to a-Si (the top layer of SOI) by dry etching.
Combining the above two methods, 2-dimensional photonic crystal waveguide can be fabricated rapidly. When compared with the high cost and slow e-beam writing technique, the above two methods are economically and technically advantaged. It also overcomes the diffraction limit of conventional mask photolithography and line width limited issue of direct laser beam writing technique.
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Yan, Cai-Xia. "Fabrication of 2D Photonic Crystal Slab Waveguides using Near-Field Phase-Shifting Contact Lithography and Interference Lithography." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1607200712173000.
Full text