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Sample records for 2d photonic crystals

  1. Photonic band gap engineering in 2D photonic crystals

    Yogita Kalra; R K Sinha

    2006-12-01

    The polarization-dependent photonic band gaps (TM and TE polarizations) in two-dimensional photonic crystals with square lattices composed of air holes in dielectric and vice versa i.e., dielectric rods in air, using the plane-wave expansion method are investigated. We then study, how the photonic band gap size is affected by the changing ellipticity of the constituent air holes/dielectric rods. It is observed that the size of the photonic band gap changes with changing ellipticity of the constituent air holes/dielectric rods. Further, it is reported, how the photonic band gap size is affected by the change in the orientation of the constituent elliptical air holes/dielectric rods in 2D photonic crystals.

  2. Progress in 2D photonic crystal Fano resonance photonics

    Zhou, Weidong; Zhao, Deyin; Shuai, Yi-Chen; Yang, Hongjun; Chuwongin, Santhad; Chadha, Arvinder; Seo, Jung-Hun; Wang, Ken X.; Liu, Victor; Ma, Zhenqiang; Fan, Shanhui

    2014-01-01

    In contrast to a conventional symmetric Lorentzian resonance, Fano resonance is predominantly used to describe asymmetric-shaped resonances, which arise from the constructive and destructive interference of discrete resonance states with broadband continuum states. This phenomenon and the underlying mechanisms, being common and ubiquitous in many realms of physical sciences, can be found in a wide variety of nanophotonic structures and quantum systems, such as quantum dots, photonic crystals, plasmonics, and metamaterials. The asymmetric and steep dispersion of the Fano resonance profile promises applications for a wide range of photonic devices, such as optical filters, switches, sensors, broadband reflectors, lasers, detectors, slow-light and non-linear devices, etc. With advances in nanotechnology, impressive progress has been made in the emerging field of nanophotonic structures. One of the most attractive nanophotonic structures for integrated photonics is the two-dimensional photonic crystal slab (2D PCS), which can be integrated into a wide range of photonic devices. The objective of this manuscript is to provide an in depth review of the progress made in the general area of Fano resonance photonics, focusing on the photonic devices based on 2D PCS structures. General discussions are provided on the origins and characteristics of Fano resonances in 2D PCSs. A nanomembrane transfer printing fabrication technique is also reviewed, which is critical for the heterogeneous integrated Fano resonance photonics. The majority of the remaining sections review progress made on various photonic devices and structures, such as high quality factor filters, membrane reflectors, membrane lasers, detectors and sensors, as well as structures and phenomena related to Fano resonance slow light effect, nonlinearity, and optical forces in coupled PCSs. It is expected that further advances in the field will lead to more significant advances towards 3D integrated photonics, flat

  3. Photonic band gap of 2D complex lattice photonic crystal

    GUAN Chun-ying; YUAN Li-bo

    2009-01-01

    It is of great significance to present a photonic crystal lattice structure with a wide photonic bandgap. A two-dimension complex lattice photonic crystal is proposed. The photonic crystal is composed of complex lattices with triangular structure, and each single cell is surrounded by six scatterers in an hexagon. The photonic band gaps are calculated based on the plane wave expansion (PWE) method. The results indicate that the photonic crystal has tunable large TM polarization band gap, and a gap-midgap ratio of up to 45.6%.

  4. Photonic crystals to enhance light extraction from 2D materials

    Noori, Yasir J; Roberts, Jonathan; Woodhead, Christopher; Bernardo-Gavito, Ramon; Tovee, Peter; Young, Robert J

    2016-01-01

    We propose a scheme for coupling 2D materials to an engineered cavity based on a defective rod type photonic crystal lattice. We show results from numerical modelling of the suggested cavity design, and propose using the height profile of a 2D material transferred on top of the cavity to maximise coupling between exciton recombination and the cavity mode. The photonic structure plays a key role in enhancing the launch efficiency, by improving the directionality of the emitted light to better couple it into an external optical system. When using the photonic structure, we measured an increase in the extraction ratio by a factor of 3.4. We investigated the variations in the flux spectrum when the radius of the rods is modified, and when the 2D material droops to a range of different heights within the cavity. We found an optimum enhancement when the rods have a radius equal to 0.165 times the lattice constant, this enhancement reduces when the radius is reduced or increased. Finally, we discuss the possible use...

  5. Ultrahigh-Q modes in anisotropic 2D photonic crystal

    In this work, we design a two-dimensional photonic crystal cavity made with a substrate of an anisotropic material. We consider triangular lattice photonic crystal made from air holes in tellurium. The cavity itself is then created by three missing holes in the centre. Using the three-dimensional finite-difference time-domain simulation and optimization of the geometrical parameters and the symmetric displacement of the edge air holes on the quality factor, the cavity’s structural parameters yield an ultrahigh-Q mode cavity with quality factor Q = 2.95 × 1011 for a filling factor r/a = 0.45 and lateral displacement of 10 nm. This shows great enhancement compared with previous studies in which silicon material has been used. The designed structure can be helpful in a number of applications associated with photonic crystal cavities, including quantum information processing, filters, and nanoscale sensors. (paper)

  6. Micrometer-Thin Crystalline-Silicon Solar Cells Integrating Numerically Optimized 2-D Photonic Crystals

    Depauw, V; Meng, X.; Daif, O. El; Gomard, G.; Lalouat, L; Drouard, E; Trompoukis, C.; Fave, A.; SEASSAL, C; Gordon, I.

    2013-01-01

    A 2-D photonic crystal was integrated experimentally into a thin-film crystalline-silicon solar cell of 1-{\\mu}m thickness, after numerical optimization maximizing light absorption in the active material. The photonic crystal boosted the short-circuit current of the cell, but it also damaged its open-circuit voltage and fill factor, which led to an overall decrease in performances. Comparisons between modeled and actual optical behaviors of the cell, and between ideal and actual morphologies,...

  7. Investigation of frequency-selective devices based on a microstrip 2D photonic crystal

    Belyaev, B. A.; Khodenkov, S. A.; Shabanov, V. F.

    2016-04-01

    The frequency-selective properties of structures based on a 2D microstrip photonic crystal have been investigated theoretically and experimentally. It is shown that various microwave devices, including diplexers, bandpass filters, and double bandpass filters, can be designed based on these structures.

  8. High intensity polarization entangled source with a 2D nonlinear photonic crystal

    Wang, Qin

    2009-01-01

    We gave a proposal on how to use a piece of two-dimension (2D) nonlinear photonic crystal to generate a polarization entangled source. It provides not only has a high stability, but also a high entangled quality and a high intensity. Moreover, our scheme involves only practical experimental...... conditions and setup. Therefore, it has a potential application in quantum information field...

  9. Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

    K.R. Maskaly

    2005-06-01

    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 1D 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. 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 quarterwave 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 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with

  10. Fabrication of high aspect ratio microtube arrays for 2D photonic crystals

    This paper describes the fabrication of 2D photonic crystals made of high aspect ratio Si microtube arrays. The tube fabrication is based on the creation of macropore arrays in n-doped Si substrates via photoassisted electrochemical etching. These macropores are successively filled using thermal oxidation and chemical vapor depostion. The substrate material is partially removed by a KOH immersion, and the filled macropores are exposed, forming arrays of microtubes with very high aspect ratios of up to 1:60. Point and line defects are introduced into some of the tube arrays by selectively omitting macropores during the fabrication. The mechanical properties of the tubes were investigated by measuring their stiffness and elastic modulus using an atomic force microscope based setup. Additionally, the resonant modes of the microtubes were simulated with FEM methods. Optical simulations reveal that these tube arrays form 2D photonic crystals, which can contain bandgaps for TM polarized light. It is also shown that the optical properties of the photonic crystals depend strongly on the tube filling factor. Adjusting the filling factor of the tubes allows tuning of the photonic properties of the tube arrays. (papers)

  11. All-optical digital 4 × 2 encoder based on 2D photonic crystal ring resonators

    Moniem, Tamer A.

    2016-04-01

    The photonic crystals draw significant attention to build all-optical logic devices and are considered one of the solutions for the opto-electronic bottleneck via speed and size. The paper presents a novel optical 4 × 2 encoder based on 2D square lattice photonic crystals of silicon rods. The main realization of optical encoder is based on the photonic crystal ring resonator NOR gates. The proposed structure has four logic input ports, two output ports, and two bias input port. The photonic crystal structure has a square lattice of silicon rods with a refractive index of 3.39 in air. The structure has lattice constant 'a' equal to 630 nm and bandgap range from 0.32 to 044. The total size of the proposed 4 × 2 encoder is equal to 35 μm × 35 μm. The simulation results using the dimensional finite difference time domain and Plane Wave Expansion methods confirm the operation and the feasibility of the proposed optical encoder for ultrafast optical digital circuits.

  12. Absolute photonic band gap in 2D honeycomb annular photonic crystals

    Highlights: • A two-dimensional honeycomb annular photonic crystal (PC) is proposed. • The absolute photonic band gap (PBG) is studied. • Annular PCs show larger PBGs than usual air-hole PCs for high refractive index. • Annular PCs with anisotropic rods show large PBGs for low refractive index. • There exist optimal parameters to open largest band gaps. - Abstract: Using the plane wave expansion method, we investigate the effects of structural parameters on absolute photonic band gap (PBG) in two-dimensional honeycomb annular photonic crystals (PCs). The results reveal that the annular PCs possess absolute PBGs that are larger than those of the conventional air-hole PCs only when the refractive index of the material from which the PC is made is equal to 4.5 or larger. If the refractive index is smaller than 4.5, utilization of anisotropic inner rods in honeycomb annular PCs can lead to the formation of larger PBGs. The optimal structural parameters that yield the largest absolute PBGs are obtained

  13. Light trapping at Dirac point in 2D triangular Archimedean-like lattice photonic crystal.

    Mao, Qiuping; Xie, Kang; Hu, Lei; Li, Qian; Zhang, Wei; Jiang, Haiming; Hu, Zhijia; Wang, Erlei

    2016-04-20

    Optical cavities and waveguides are critical parts of modern optical devices. Traditionally, optical cavities and waveguides rely on photonic bandgaps, or total internal reflection, to achieve light trapping. It has been reported that a novel light trapping, which exists in triangular and honeycomb lattices, is attributed to the so-called Dirac point. Our analysis reveals that 2D triangular Archimedean-like lattice photonic crystals also can support this Dirac mode with similar characteristics. This is a new type of localized mode with a different algebraic field profile at a different specified Dirac frequency, which is also beyond any complete photonic bandgap. The new wave localization has different features and can be applied to the design of new optical devices. PMID:27140119

  14. Band gap studies of 2D photonic crystals with hybrid scatterers

    Two-dimensional (2D) photonic crystals (PCs) of a square lattice with dielectric hybrid rods in air are proposed; these PCs consist of a square rod at the center of the unit cell and additional circular rods with their outermost edges against the middle of each side of the lattice unit cell. The band gap structures of PCs can be tailored and optimized by rotating the square rods and adding circular rods to the lattice unit cell. The variation of bands near the complete photonic band gap boundaries, due to some specific modes, is sensitive to certain structural parameters of the system. The results can be understood by analyzing the spatial energy distribution of the electromagnetic fields. Based on such a field analysis, a novel interpretative model is proposed. The PC can be fabricated easily and operated in the microwave region and, hence, should be suitable for applications in new microwave devices.

  15. Fabrication of integrated bimorphs with self aligned tips for optical switching in 2-d photonic crystal waveguides

    Chakkalakkal Abdulla, S.M.; Kauppinen, L.J.; Dijkstra, M.; Boer, de M.J.; Berenschot, E.; Ridder, de R.M.; Krijnen, G.J.M.

    2010-01-01

    This paper presents the fabrication technology for a novel class of photonic devices. This technology integrates silicon 2-D photonic crystal (PhC) waveguides and electrostatically actuated bimorph cantilevers with tips that are self-aligned relative to the holes of the PhC. The bimorph cantilevers

  16. 2D photonic crystal complete band gap search using a cyclic cellular automaton refination

    González-García, R.; Castañón, G.; Hernández-Figueroa, H. E.

    2014-11-01

    We present a refination method based on a cyclic cellular automaton (CCA) that simulates a crystallization-like process, aided with a heuristic evolutionary method called differential evolution (DE) used to perform an ordered search of full photonic band gaps (FPBGs) in a 2D photonic crystal (PC). The solution is proposed as a combinatorial optimization of the elements in a binary array. These elements represent the existence or absence of a dielectric material surrounded by air, thus representing a general geometry whose search space is defined by the number of elements in such array. A block-iterative frequency-domain method was used to compute the FPBGs on a PC, when present. DE has proved to be useful in combinatorial problems and we also present an implementation feature that takes advantage of the periodic nature of PCs to enhance the convergence of this algorithm. Finally, we used this methodology to find a PC structure with a 19% bandgap-to-midgap ratio without requiring previous information of suboptimal configurations and we made a statistical study of how it is affected by disorder in the borders of the structure compared with a previous work that uses a genetic algorithm.

  17. Nonlinear Raman-Nath diffraction of femtosecond laser pulses in a 2D nonlinear photonic crystal.

    Vyunishev, A M; Arkhipkin, V G; Slabko, V V; Baturin, I S; Akhmatkhanov, A R; Shur, V Ya; Chirkin, A S

    2015-09-01

    We study second-harmonic generation (SHG) of femtosecond laser pulses in a rectangular two-dimensional nonlinear photonic crystal (NLPC). Multiple SH beams were observed in the vicinity of the propagation direction of the fundamental beam. It has been verified that the angular positions of these beams obey the conditions of nonlinear Raman-Nath diffraction (NRND). The measured SH spectra of specific NRND orders consist of narrow peaks that experience a high-frequency spectral shift as the order grows. We derive an analytical expression for the process studied and find the theoretical results to be in good agreement with the experimental data. We estimate the enhancement factor of nonlinear Raman-Nath diffraction in 2D NLPC to be 70. PMID:26368697

  18. Remarkable enhancement of upconversion luminescence on 2-D anodic aluminum oxide photonic crystals.

    Wang, He; Yin, Ze; Xu, Wen; Zhou, Donglei; Cui, Shaobo; Chen, Xu; Cui, Haining; Song, Hongwei

    2016-05-21

    Lanthanide-doped upconversion nanoparticles (UCNPs) are attracting extensive attention due to their unique physical properties and great application potential. However, the lower luminescence quantum yield/strength is still an obstacle for real application. Local field modulation is a promising method to highly enhance the upconversion luminescence (UCL) of the UCNPs. In this work, a novel kind of two-dimensional photonic crystal (2D-PC), anodic aluminum oxides (AAOs), was explored to improve the UCL of NaYF4:Yb(3+),Er(3+) nanoplates (NPs). An optimum enhancement factor (EF) of 65-fold was obtained for the overall intensity of Er(3+) under 980 nm excitation, and 130-fold for the red emission. Systematic studies indicate that UCL enhancement mainly originates from the enlargement of the excitation field by scattering and reflection of AAO PCs. It should also be highlighted that the modulation of 2D-PC on the UCL of NaYF4:Yb(3+),Er(3+) NPs demonstrates weak size-dependent and thickness-dependent behavior, which is well consistent with the stimulated electromagnetic field distribution by the finite difference time domain (FDTD) method. PMID:27139324

  19. High-Q side-coupled semi-2D-photonic crystal cavity.

    Zhang, Jianhao; Liu, Weixi; Shi, Yaocheng; He, Sailing

    2016-01-01

    High-Q semi-2D-photonic crystal cavities with a tapered edge and side-coupled bus waveguide are demonstrated. With a quadratic design, the unloaded cavity presents a theoretical ultrahigh quality factor up to 6.7 × 10(7) for the condition that there are mere 34 holes in the propagated direction, which is pretty close to the 2D and 1D counterpart. Combined with a side-coupled bus waveguide, an all-pass-type cavity with a loaded quality factor (Q) of over 2.4 × 10(4) and an extinction ratio over 10 dB are experimentally demonstrated. An experimental loaded Q up to 1.1 × 10(5) are also achieved by tuning the coupling between the cavity and the bus waveguide, which is much larger than any reported surface-mode cavity. This cavity is quite suitable for sensors, filters and especially optomechanical devices thanks to the mechanical stability of the cavity and flexibility of the bus waveguide. PMID:27194203

  20. Study of the photonic crystal waveguide based on 2D compound lattice structure

    WU Chao-jun; LI Yan-ping; WANG Zi-u

    2009-01-01

    group velocity dispersion compensation can be realized by the structure optimization. The results provide a reference for the study and application of photonic crystal waveguide based on the compound lattice structure.

  1. Tunable 2D Photonic Crystal Cavities for Cavity Electro-Optomechanics

    Winger, Martin; Alegre, Thiago P. Mayer; Safavi-Naeini, Amir H.; Painter, Oskar

    2011-01-01

    We present and demonstrate a novel electro-opto-mechanical structure based on a slotted waveguide photonic-crystal cavity, in which electrostatics and optics couple simultaneously to the same "phonon" resonance.

  2. Fabrication technology of heterojunctions in the lattice of a 2D photonic crystal based on macroporous silicon

    Design and fabrication technology of a microcavity structure based on a double heterojunction in macroporous silicon is suggested. The fabrication process of a strip of a 2D photonic crystal constituted by a finite number of lattice periods and the technique for defect formation by local opening of macropores on the substrate side, followed by filling of these macropores with a nematic liquid crystal, are considered.

  3. High-Q Defect-Free 2D Photonic Crystal Cavity from Random Localised Disorder

    Kelvin Chung

    2014-07-01

    Full Text Available We propose a high-Q photonic crystal cavity formed by introducing random disorder to the central region of an otherwise defect-free photonic crystal slab (PhC. Three-dimensional finite-difference time-domain simulations determine the frequency, quality factor, Q, and modal volume, V, of the localized modes formed by the disorder. Relatively large Purcell factors of 500–800 are calculated for these cavities, which can be achieved for a large range of degrees of disorders.

  4. Formation of 2D photonic crystal bars by simultaneous photoelectrochemical etching of trenches and macropores in silicon

    Joint electrochemical etching of deep macropores and trenches in n-Si (100) has been studied. After the substrate was removed, regions of a sample, bounded on all sides by a closed contour of through trenches, were extracted from the sample, with narrow bars of a 2D photonic crystal remaining. The influence exerted by the distance between pores and a trench and by the modes of etching and subsequent oxidation on the roughness of the side walls of the structures and also on the size and shape of pores near the trench is analyzed for the example of a photonic crystal with a square lattice of macropores. Conditions are found in which the lattice distortion of the photonic crystal is at a minimum and the side walls of the structure are the smoothest (root-mean-square roughness height ∼60 nm).

  5. A statistical approach for measuring dislocations in 2D photonic crystals

    Malureanu, Radu; Frandsen, Lars Hagedorn

    2008-01-01

    In this paper, a comparison between the placement accuracy of lattice atoms in photonic crystal structures fabricated with different lithographic techniques is made. Using atomic force microscopy measurements and self-developed algorithms for calculating the holes position within less than 0.01nm...

  6. Bandgap characteristics of 2D plasma photonic crystal with oblique incidence: TM case

    Xie Ying-Tao; Yang Li-Xia

    2011-01-01

    A novel periodic boundary condition (PBC), that is the constant transverse wavenumber (CTW) method, is introduced to solve the time delay in the transverse plane with oblique incidence. Based on the novel PBC, the FDTD/PBC algorithm is proposed to study periodic structure consisting of plasma and vacuum. Then the reflection coefficient for the plasma slab from the FDTD/PBC algorithm is compared with the analytic results to show the validity of our technique. Finally, the reflection coefficients for the plasma photonic crystals are calculated using the FDTD/PBC algorithm to study the variation of bandgap characteristics with the incident angle and the plasma parameters. Thus it has provided the guiding sense for the actual manufacturing plasma photonic crystal.

  7. Optical properties of GaAs 2D hexagonal and cubic photonic crystal

    Arab, F., E-mail: farab@CDTA.DZ; Assali, A.; Grain, R.; Kanouni, F. [Centre for Development of Advanced Technologies (CDTA) Research Unit in Optics and Photonics (UROP), University of Setif 1, El Bez, 19000 Setif (Algeria)

    2015-03-30

    In this paper we present our theoretical study of 2D hexagonal and cubic rods GaAs in air, with plan wave expansion (PWE) and finite difference time domain (FDTD) by using BandSOLVE and FullWAVE of Rsoft photonic CAD package. In order to investigate the effect of symmetry and radius, we performed calculations of the band structures for both TM and TE polarization, contour and electromagnetic propagation and transmission spectra. Our calculations show that the hexagonal structure gives a largest band gaps compare to cubic one for a same filling factor.

  8. Novel high-Q modes in thick 2D photonic crystal slabs

    The periodic nature of photonic crystals (PCs) (Yablonovitch 1987 Phys. Rev. Lett. 58 2059–62; John 1987 Phys. Rev. Lett. 58 2486–9) has been extensively exploited for the past quarter of a century using photonic bandgap (PBG) effects to manipulate photons in engineered electromagnetic structures. Structures such as photonic crystal nanocavities are widely considered to be key in realizing future nanoscale optoelectronic devices. These cavities are capable of creating resonant modes with high-quality factor (Q) and small mode volume, in other words a large Purcell factor (Purcell 1946 Phys. Rev. 69 681), and have been widely researched in the two-dimensional photonic crystal slab (PCS) defect cavity configuration (Painter et al 1999 J. Opt. Soc. Am. B 16 275–85). Here, we demonstrate for the first time how three confinement mechanisms are thought to coincide to give rise to a high-Q resonance for a slab containing a modified L3 defect where the slab thickness is such that the guiding in the slab is no longer single moded (Tandaechanurat et al 2008 Opt. Express 16 448–55). This is in contrast to the conventional design approach, where the PCS thickness is chosen to be of the order of half a lattice constant to ensure that a PBG exists to confine cavity modes strongly within the slab (Painter et al 1999 J. Opt. Soc. Am. B 16 275–85; Johnson et al 1999 Phys. Rev. B 60 5751–8; Khankhoje et al 2010 Nanotechnology 21 065202). These newly identified high-Q modes can be important in terms of the fabrication of slabs and other devices such as vertical pillars since they allow high-Q factors in thicker and more fabrication tolerant geometries. (paper)

  9. 2D photonic crystal logic gates based on self-collimated effect

    Fan, Ranran; Yang, Xiulun; Meng, Xiangfeng; Sun, Xiaowen

    2016-08-01

    Four kinds of logic gates are proposed using interference between the self-collimated beams in photonic crystals, namely NOT, OR, AND and XOR gates, which can be used in the design of photonic integrated circuits. The radius of the splitter and the optical path difference between splitters are adjusted to produce certain phase difference between the reflected and transmitted beams, which may interfere constructively or destructively to realize logical operation. They have high contrast ratios and low power consumption, the extinction ratio between logic 1 and logic 0 for NOT and AND gates can reach 24.7 dB, 30 dB and 12.6 dB for the wavelength used by optical communication (1550 nm), respectively, which makes it potentially applicable for photonic integrated circuits.

  10. Fano Resonance in GaAs 2D Photonic Crystal Nanocavities

    We report the results of polarization resolved reflectivity experiments in GaAs air-bridge photonic crystals with L3 cavities. We show that the fundamental L3 cavity mode changes, in a controlled way, from a Lorentzian symmetrical lineshape to an asymmetrical form when the linear polarization of the incident light is rotated in the plane of the crystal. The different lineshapes are well fitted by the Fano asymmetric equation, implying that a Fano resonance is present in the reflectivity. We use the scattering matrix method to model the Fano interference between a localized discrete state (the cavity fundamental mode) and a background of continuum states (the light reflected from the crystal slab in the vicinity of the cavity) with very good agreement with the experimental data.

  11. Tuning the Structural Color of a 2D Photonic Crystal Using a Bowl-like Nanostructure.

    Umh, Ha Nee; Yu, Sungju; Kim, Yong Hwa; Lee, Su Young; Yi, Jongheop

    2016-06-22

    Structural colors of the ordered photonic nanostructures are widely used as an effective platform for manipulating the propagation of light. Although several approaches have been explored in attempts to mimic the structural colors, improving the reproducibility, mechanical stability, and the economic feasibility of sophisticated photonic crystals prepared by complicated processes continues to pose a challenge. In this study, we report on an alternative, simple method for fabricating a tunable photonic crystal at room temperature. A bowl-like nanostructure of TiO2 was periodically arranged on a thin Ti sheet through a two-step anodization process where its diameters were systemically controlled by changing the applied voltage. Consequently, they displayed a broad color distribution, ranging from red to indigo, and the principal reason for color generation followed the Bragg diffraction theory. This noncolorant method was capable of reproducing a Mondrian painting on a centimeter scale without the need to employ complex architectures, where the generated structural colors were highly stable under mechanical or chemical influence. Such a color printing technique represents a potentially promising platform for practical applications for anticounterfeit trademarks, wearable sensors, and displays. PMID:27245939

  12. Nanophotonic Filters and Integrated Networks in Flexible 2D Polymer Photonic Crystals

    Gan, Xuetao; Tsai, Cheng-Chia; Li, Luozhou; Englund, Dirk

    2013-01-01

    Polymers have appealing optical, biochemical, and mechanical qualities, including broadband transparency, ease of functionalization, and biocompatibility. However, their low refractive indices have precluded wavelength-scale optical confinement and nanophotonic applications in polymers. Here, we introduce a suspended polymer photonic crystal (SPPC) architecture that enables the implementation of nanophotonic structures typically limited to high-index materials. Using the SPPC platform, we demonstrate nanophotonic band-edge filters, waveguides, and nanocavities featuring quality ($Q$) factors exceeding $2,300$ and mode volumes ($V_{mode}$) below \\textbf{$1.7(\\lambda/n)^{3}$}. The unprecedentedly high $Q/V_{mode}$ ratio results in a spectrally selective enhancement of radiative transitions of embedded emitters via the cavity Purcell effect with an enhancement factor exceeding 100. Moreover, the SPPC architecture allows straightforward integration of nanophotonic networks, shown here by a waveguide-coupled cavit...

  13. High plasmon concentration on the surfaces of rectangular metallic rods embedded in air in a 2D photonic crystal

    Calvo-Velasco, D. M.; Porras-Montenegro, N.

    2016-04-01

    Using the revised plane wave method, we calculated the photonic band structure (PBS) considering TE polarization of a square 2D photonic crystal made of rectangular metallic rods embedded in air. In case of square rods and comparing different plasma frequencies, we found a characteristic band distribution related with the existence of localized plasmons on the rod surfaces, and also we found that this type of rod shape contributes to a high concentration of the electromagnetic field close to the rod corners. Considering rectangular rods and varying one of the sides of the rods, we found a PBS that presents a reorganization of the bands in comparing with the low dispersion present in the square rod case, related with a high localization of the radiation on the rod surfaces.

  14. Design of a quasi-2D photonic crystal optomechanical cavity with tunable, large $x^2$-coupling

    Kalaee, Mahmoud; Pfeifer, Hannes; Painter, Oskar

    2016-01-01

    We present the optical and mechanical design of a mechanically compliant quasi-two-dimensional photonic crystal cavity formed from thin-film silicon in which a pair of linear nanoscale slots are used to create two coupled high-$Q$ optical resonances. The optical cavity supermodes, whose frequencies are designed to lie in the $1500$~nm wavelength band, are shown to interact strongly with mechanical resonances of the structure whose frequencies range from a few MHz to a few GHz. Depending upon the symmetry of the mechanical modes and the symmetry of the slot sizes, we show that the optomechanical coupling between the optical supermodes can be either linear or quadratic in the mechanical displacement amplitude. Tuning of the nanoscale slot size is also shown to adjust the magnitude and sign of the cavity supermode splitting $2J$, enabling near-resonant motional scattering between the two optical supermodes and greatly enhancing the $x^2$-coupling strength. Specifically, for the fundamental flexural mode of the c...

  15. A super narrow band filter based on silicon 2D photonic crystal resonator and reflectors

    Wang, Yuanyuan; Chen, Deyuan; Zhang, Gang; Wang, Juebin; Tao, Shangbin

    2016-03-01

    In this paper, a novel structure of super narrow band filter based on two-dimensional square lattice photonic crystals of silicon rods in air for 1.5 um communication is proposed and studied. COMSOL Multiphysics4.3b software is used to simulate the optical behavior of the filter. The filter consists of one point-defect-based resonator and two line-defect-based reflectors. The resonance frequency, transmission coefficient and quality factor are investigated by varying the parameters of the structure. In design, a silicon rod is removed to form the resonator; for the rows of rods above and below the resonator, a part of the rods are removed to form the reflectors. By optimizing the parameters of the filter, the quality factor and transmission coefficient of the filter at the resonance frequency of 2e14 Hz can reach 1330 and 0.953, respectively. The super narrow band filter can be integrated into optical circuit for its micron size. Also, it can be used for wavelength selection and noise filtering of optical amplifier in future communication application.

  16. Ultrasensitive and compact tunable electro-optic filter in a 2D silicon photonic-crystal cavity

    Ebrahimy, Mehdi N.; Naziri, Mohammad; Andalib, Alireza; Daie Kuzekanani, Ziaddin

    2016-06-01

    In this work, we designed and simulated a high Q-factor photonic crystal cavity with a PN junction to demonstrate a high-sensitivity and high tunable electro-optic filter (EOF). For this purpose, we used a cavity based on 2D photonic crystal structures and created a PN junction with 1 μm width in the center of the cavity to change the refractive index of it. The electro-optic sensitivity of the cavity was improved by reducing modal volume and scattering power. Reverse bias in the range of (‑3.88 V–0.288 V) is applied to the PN junction and the output spectrum is investigated for various bias voltages. The output wavelengths of designed EOF can be tuned by manipulating cavity cells. In final response of EOF the maximum transmission efficiency is more than 93%, the overall Q-factor is more than 14 500. The whole device fits in a compact 102.6 μm2 (17.4 μm  ×  5.9 μm) footprint.

  17. Optimization of band gaps of 2D photonic crystals by the rapid generic algorithm

    SUN Yun-tao

    2011-01-01

    @@ Based on the rapid genetic algorithm (RGA), the band gap structures of square lattices with square scatters are optimized.In the optimizing process, gene codes are used to express square scatters and the fitting function adopts the relative values of the largest absolute photonic band gaps (PBGs).By changing the value of filling factor, three cell forms with large photonic band gaps are obtained.In addition, the comparison between the rapid genetic algorithm and the general genetic algorithm (GGA) is analyzed.

  18. Extreme group index measured and calculated in 2D SOI-based photonic crystal waveguides

    Lavrinenko, Andrei; Jacobsen, Rune Shim; Fage-Pedersen, Jacob; Frandsen, Lars Hagedorn; Zsigri, Beata; Peucheret, Christophe; Borel, Peter Ingo

    2005-01-01

    lattice of air-holes in the 216-nm thick silicon layer in an SOI material. Experimental transmission spectra show a mode cut-off around 1562.5 nm for the fundamental photonic bandgap mode. In order to measure and model the group index of modes in the PCW, a time-of-flight (ToF) method is applied....

  19. Large Area 2D and 3D Colloidal Photonic Crystals Fabricated by a Roll-to-Roll Langmuir-Blodgett Method.

    Parchine, Mikhail; McGrath, Joe; Bardosova, Maria; Pemble, Martyn E

    2016-06-14

    We present our results on the fabrication of large area colloidal photonic crystals on flexible poly(ethylene terephthalate) (PET) film using a roll-to-roll Langmuir-Blodgett technique. Two-dimensional (2D) and three-dimensional (3D) colloidal photonic crystals from silica nanospheres (250 and 550 nm diameter) with a total area of up to 340 cm(2) have been fabricated in a continuous manner compatible with high volume manufacturing. In addition, the antireflective properties and structural integrity of the films have been enhanced via the use of a second roll-to-roll process, employing a slot-die coating of an optical adhesive over the photonic crystal films. Scanning electron microscopy images, atomic force microscopy images, and UV-vis optical transmission and reflection spectra of the fabricated photonic crystals are analyzed. This analysis confirms the high quality of the 2D and 3D photonic crystals fabricated by the roll-to-roll LB technique. Potential device applications of the large area 2D and 3D colloidal photonic crystals on flexible PET film are briefly reviewed. PMID:27218474

  20. Mapping the broadband polarization properties of linear 2D SOI photonic crystal waveguides

    Canning, John; Skivesen, Nina; Kristensen, Martin;

    2007-01-01

    Both quasi-TE and TM polarisation spectra for a silicon- on-insulator (SOI) waveguide are recorded over (1100-1700) nm using a broadband supercontinuum source. By studying both the input and output polarisation eigenstates we observe narrowband resonant cross coupling near the lowest quasi-TE mode...... cut-off. We also observe relatively broadband mixing between the two eigenstates to generate a complete photonic bandgap. By careful analysis of the output polarisation state we report on an inherent non-reciprocity between quasi TE and TM fundamental mode cross coupling. The nature of polarisation...

  1. Coupling Analysis of Electromagnetic Field Transverse Magnetic (TM) on 2D Photonic Crystals with Symmetrical Refractive Index Defect Using Tensor Green Method

    Kurniawan, Candra

    2012-01-01

    Photonic crystal is a dielectric material which has a refractive index or permittivity which vary periodically, thus preventing the propagation of light with specific frequency and direction. The frequency range is called a photonic bandgap (PBG). If the structure of photonic crystals is modified by taking one line of rod in a photonic crystal is obtained a waveguide. Giving structures with symmetrical defects around the waveguide channel with the parameters given occurs coupling between the waveguide and cavity. Coupling indicates transfer part or all of the EM field depends on the frequency of EM field in the photonic crystal. Green tensor method can be used to calculate the total electric field in a 2D photonic crystal. With the aid of MATLAB programs can be shown to the powerful visualization calculation of the total electrical field in 2D photonic crystals. Based on analysis of the literature and the bandgap graphic and the field energy in the defects show that effective frequency which produces maximum ...

  2. Integration of 2D and 3D nanostructure fabrication with wafer-scale microelectronics: Photonic crystals and graphene

    Arpiainen, Sanna

    2015-01-01

    This Thesis considers different aspects of heterogeneous integration of 2- and 3-dimensional nanostructures with today's microelectronics process flow. The applications in the main focus are integrated 3D photonic crystals on a photonic chip and graphene biosensors, both exploiting directed self-assembly but at different length scales. View point is from the fabrication and integration challenges, but the future prospects of the selected fields of applications are also reviewed. Utilizatio...

  3. Planar photonic crystal

    Nedeljkovic, Dusan; Pearsall, T. P.; Kuchinsky, S. A.; Mikhailov, M. D.; Lončar, Marko; Scherer, Axel

    2001-01-01

    We present results of guiding light in a single-line-defect planar photonic crystal (PPC) waveguide with 90° and 60° bends. The wave guiding is obtained by total internal reflection perpendicular to the plane of propagation and by the photonic band gap for the 2D photonic crystal in the plane. The results for photonic waveguiding are shown and demonstrated at 1.5 µm wavelength.

  4. Influence of elliptical shaped holes on the sensitivity and Q factor in 2D photonic crystals sensor

    Benmerkhi, A.; Bouchemat, M.; Bouchemat, T.

    2016-07-01

    We theoretically investigate the refractive index sensor based on L2 photonic crystal cavity where neighboring holes are locally infiltrated with polymers. The photonic crystal is composed of periodic triangular hole array patterned perpendicularly to an InP-based confining heterostructure. The number of the holes surrounding a L2 cavity and their shape were modified in order to optimize the sensitivity and quality factor. From this study we have selected two structures that have good results. The first one is called locally which has a very high Q factor and a good sensitivity. Their values are 6.03 × 106 and 163 nm/RIU, respectively. The second optimized structure is called design B, which has a high sensitivity toward 227.78 nm/RIU with a Q factor of 5 × 105. The calculated detect limit for the two designs are lower than 1.59 × 10-6 and 1.4 × 10-5 RIU, respectively.

  5. Label-free optical detection of C-reactive protein by nanoimprint lithography-based 2D-photonic crystal film.

    Endo, Tatsuro; Kajita, Hiroshi; Kawaguchi, Yukio; Kosaka, Terumasa; Himi, Toshiyuki

    2016-06-01

    The development of high-sensitive, and cost-effective novel biosensors have been strongly desired for future medical diagnostics. To develop novel biosensor, the authors focused on the specific optical characteristics of photonic crystal. In this study, a label-free optical biosensor, polymer-based two-dimensional photonic crystal (2D-PhC) film fabricated using nanoimprint lithography (NIL), was developed for detection of C-reactive protein (CRP) in human serum. The nano-hole array constructed NIL-based 2D-PhC (hole diameter: 230 nm, distance: 230, depth: 200 nm) was fabricated on a cyclo-olefin polymer (COP) film (100 µm) using thermal NIL and required surface modifications to reduce nonspecific adsorption of target proteins. Antigen-antibody reactions on the NIL-based 2D-PhC caused changes to the surrounding refractive index, which was monitored as reflection spectrum changes in the visible region. By using surface modified 2D-PhC, the calculated detection limit for CRP was 12.24 pg/mL at an extremely short reaction time (5 min) without the need for additional labeling procedures and secondary antibody. Furthermore, using the dual-functional random copolymer, CRP could be detected in a pooled blood serum diluted 100× with dramatic reduction of nonspecific adsorption. From these results, the NIL-based 2D-PhC film has great potential for development of an on-site, high-sensitivity, cost-effective, label-free biosensor for medical diagnostics applications. PMID:27150702

  6. Design and Analysis of a 2D-PhotonicCrystal Fiber Structure with Ultra-Flattened Dispersion and Single Mode Operation over a Wide Range of Wavelength

    Sandhir K Singh

    2010-03-01

    Full Text Available A photonic crystal fiber (PCF presents a new way to guide light. The air holes in the fiber work as a cladding, but provide much more flexibility in the design. In this work, the plane-wave expansion technique for generating and analyzing photonic band structures is used. The simple 2D XY array with a hexagonal cross-sectional pattern of air holes in a silicon fiber is analysed for calculating parameters such as mode effective index, dispersion and single mode operation over wide wavelength range. The results of a design sample presented in this article, showing the better result to analyze this new class of fiber. This fiber can be used for biomedical application, spectroscopy, and super continuum generation.

  7. All-optical XOR and OR logic gates based on line and point defects in 2-D photonic crystal

    Goudarzi, Kiyanoosh; Mir, Ali; Chaharmahali, Iman; Goudarzi, Dariush

    2016-04-01

    In this paper, we have proposed an all-optical logic gate structure based on line and point defects created in the two dimensional square lattice of silicon rods in air photonic crystals (PhCs). Line defects are embedded in the ГX and ГZ directions of the momentum space. The device has two input and two output ports. It has been shown analytically whether the initial phase difference between the two input beams is π/2, they interfere together constructively or destructively to realize the logical functions. The simulation results show that the device can acts as a XOR and an OR logic gate. It is applicable in the frequency range of 0-0.45 (a/λ), however we set it at (a/λ=) 0.419 for low dispersion condition, correspondingly the lambda is equal to 1.55 μm. The maximum delay time to response to the input signals is about 0.4 ps, hence the speed of the device is about 2.5 THz. Also 6.767 dB is the maximum contrast ratio of the device.

  8. Photonic crystals

    Busch, Kurt; Wehrspohn, Ralf B; Föll, Helmut

    2006-01-01

    The majority of the contributions in this topically edited book stems from the priority program SPP 1113 ""Photonische Kristalle"" run by the Deutsche Forschungsgemeinschaft (DFG), resulting in a survey of the current state of photonic crystal research in Germany. The first part of the book describes methods for the theoretical analysis of their optical properties as well as the results. The main part is dedicated to the fabrication, characterization and modeling of two- and three-dimensional photonic crystals, while the final section presents a wide spectrum of applications: gas sensors, micr

  9. Photonic crystals principles and applications

    Gong, Qihuang

    2013-01-01

    IntroductionPrimary Properties of Photonic CrystalsFabrication of Photonic CrystalsPhotonic Crystal All-Optical SwitchingTunable Photonic Crystal FilterPhotonic Crystal LaserPhotonic Crystal Logic DevicesPhotonic Crystal Sensors

  10. Photonic Eigenmodes in a Photonic Crystal Membrane

    E. Ya. Glushko; O. E. Glushko; L. A. Karachevtseva

    2012-01-01

    Photonic membranes are the most widely used kind of 2D photonic crystals in signal processing. Nevertheless, some important aspects of electromagnetic field behavior in membrane like photonic crystals (MPCs) need detail investigation. We develop the approach close to resonant coupling modes method which unites both external and intrinsic problems, in-plane and out-of-plane geometries, and resonator properties of MPC. The resonator standing modes are excited by an external source through the s...

  11. Design optimization of a low-loss and wide-band sharp 120° waveguide bend in 2D photonic crystals

    Yuan, Jianhua; Yang, Jian; Shi, Dan; Ai, Wenbao; Shuai, Tianping

    2016-05-01

    For two dimensional photonic crystals containing finite cylinders on triangle lattice, a 120° waveguide bend with low-loss and wide-band is obtained in this paper. The optimal process can be divided into two steps: firstly, a conventional waveguide bend can be introduced by maximizing the photonic bandgap; then further optimization involves shifting the position and modifying the radius of only one air hole near the bend. An optimization problem at a given frequency or over a frequency range needs to be solved. It depends on both the field solutions obtained by using the finite element method and the optimization of photonic bandgap obtained by using the plane wave expansion method. With the proposed optimal technique, the result of our optimized design for sharp 120° waveguide bends shows that an obvious low-loss transmission at wavelength 1550 nm can be observed and the maximum value of objective function is able to be rapidly obtained.

  12. Pendellosung effect in photonic crystals

    Savo, S; Miletto, C; Andreone, A; Dardano, P; Moretti, L; Mocella, V

    2008-01-01

    At the exit surface of a photonic crystal, the intensity of the diffracted wave can be periodically modulated, showing a maximum in the "positive" (forward diffracted) or in the "negative" (diffracted) direction, depending on the slab thickness. This thickness dependence is a direct result of the so-called Pendellosung phenomenon, consisting of the periodic exchange inside the crystal of the energy between direct and diffracted beams. We report the experimental observation of this effect in the microwave region at about 14 GHz by irradiating 2D photonic crystal slabs of different thickness and detecting the intensity distribution of the electromagnetic field at the exit surface and inside the crystal itself.

  13. Polymer-based photonic crystals

    Edrington, A.C.; Urbas, A.M.; Fink, Y.; Thomas, E.L. [Massachusetts Inst. of Tech., Cambridge (United States). Dept. of Materials Science and Engineering; DeRege, P. [Firmenich, Inc., Port Newark, NJ (United States); Chen, C.X.; Swager, T.M. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemistry; Hadjichristidis, N. [Athens Univ. (Greece). Dept. of Chemistry; Xenidou, M.; Fetters, L.J. [ExxonMobil Research Corp., Annandale, NJ (United States); Joannopoulos, J.D. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Physics

    2001-03-16

    The development of polymers as photonic crystals is highlighted, placing special emphasis on self-assembled block copolymers. 1D self-assembled multilayers as well as 2D and 3D self-assembled structures are examined, then intricate block polymer structures such as that shown in the Figure are discussed as are birefringent multilayer and elastomeric films. (orig.)

  14. Imprinted photonic crystal chemical sensors

    Boersma, A.; Burghoorn, M.M.A.; Saalmink, M.

    2011-01-01

    In this paper we present the use of Photonic Crystals as chemical sensors. These 2D nanostructured sensors were prepared by nano-imprint lithography during which a nanostructure is transferred from a nickel template into a responsive polymer, that is be specifically tuned to interact with the chemic

  15. Photonic crystal fibers

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D;

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  16. Superconducting photonic crystals

    Berman, Oleg L.; Lozovik, Yurii E.; Eiderman, Sergey L.; Coalson, Rob D.

    2006-01-01

    The band structure of a novel type of photonic crystal with superconducting constituent elements is calculated numerically via a plane wave expansion. The density of states and the dependence of the width of the photonic gap on the filling factor is analyzed for a two-dimensional photonic crystal consisting of an infinite array of parallel superconducting cylinders.

  17. Photonic Crystal Waveguide Fabrication

    Høvik, Jens

    2012-01-01

    This research is entirely devoted to the study and fabrication of structures with periodic dielectric constants, also known as photonic crystals (PhCs). These structures show interesting dispersion characteristics which give them a range of prohibited frequencies that are not allowed to propagate within the crystal. This property makes them suited for a wide array of photonic-based components. One-dimensional photonic crystals are already commercialized and are of widespread use in for exampl...

  18. Application of Photonic Crystals in Semiconductor Lasers

    LIU Guang-yu; WANG Li-jun; ZHANG Yan; PENG Biao; SUN Yan-fang; LI Te; CUI Jin-jiang; NING Yong-qiang; QIN Li; LIU Yun

    2007-01-01

    Photonic crystals (PCs) have attracted much considerable research attention in the past two decades. They are artificially fabricated periodic dielectric structures. The periodic dielectric structures have photonic band gap (PBG) and are referred to as photonic band gap materials. This paper mainly introduces one-dimensional (1-D) and 2D PCs applied in the semiconductor lasers.

  19. ALICE photon spectrometer crystals

    Maximilien Brice

    2006-01-01

    Members of the mechanical assembly team insert the last few crystals into the first module of ALICE's photon spectrometer. These crystals are made from lead-tungstate, a crystal as clear as glass but with nearly four times the density. When a high-energy particle passes through one of these crystals it will scintillate, emitting a flash of light allowing the energy of photons, electrons and positrons to be measured.

  20. Photonic Crystal Laser Accelerator Structures

    Cowan, Benjamin; Javanmard, Mehdi; Siemann, Robert H.

    2003-01-01

    Photonic crystals have great potential for use as laser-driven accelerator structures. A photonic crystal is a dielectric structure arranged in a periodic geometry. Like a crystalline solid with its electronic band structure, the modes of a photonic crystal lie in a set of allowed photonic bands. Similarly, it is possible for a photonic crystal to exhibit one or more photonic band gaps, with frequencies in the gap unable to propagate in the crystal. Thus photonic crystals can confine an optic...

  1. Design of Optical Tunable CNOT (XOR) and XNOR Logic Gates Based on 2D-Photonic Crystal Cavity Using Electro-Optic Effect

    Abbasian, Karim; Sadeghi, Parvin

    2016-01-01

    We have proposed optical tunable CNOT (XOR) and XNOR logic gates using two-dimensional photonic crystal (2DPhC) cavities. Where, air rods with square lattice array have been embedded in Ag-Polymer substrate with refractive index of 1.59. In this work, we have enhanced speed of logic gates by applying two input signals with a phase dif?ference at the same wavelength for 2DPhC cavities. Where, we have adjusted the phases of input and control signals equal with {\\pi}/3 and zero, respectively. The response time of the structure and quality factor of the cavities are in the range of femtosecond and 2000, respectively. Then, we have used electro-optic property of the substrate material to change the cavities resonance wavelengths. By this means, we could design the logic gates and demonstrate a tunable range of 23nm for their operation wavelength. The quality factor and the response times of cavities remain constant in the tunable range of wavelength, approximately. The evaluated least ON to OFF logic-level contras...

  2. Liquid crystal tunable photonic crystal dye laser

    Buss, Thomas; Christiansen, Mads Brøkner; Smith, Cameron; Kristensen, Anders

    2010-01-01

    We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium.

  3. Photonic Crystal Fiber Attenuator

    Joo Beom Eom; Hokyung Kim; Jinchae Kim; Un-Chul Paek; Byeong Ha Lee

    2003-01-01

    We propose a novel fiber attenuator based on photonic crystal fibers. The difference in the modal field diameters of a conventional single mode fiber and a photonic crystal fiber was used. A variable optical attenuator was also achieved by applying macro-bending on the PCF part of the proposed attenuator

  4. Active Photonic Crystal Waveguides

    Ek, Sara

    This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... crystal semiconductor optical amplier. As a step towards such a component, photonic crystal waveguides with a single quantum well, 10 quantum wells and three layers of quantum dots are fabricated and characterized. An experimental study of the amplied spontaneous emission and a implied transmission are...... presented in this thesis. A variation of photonic crystal design parameters are used leading to a spectral shift of the dispersion, it is veried that the observed effects shift accordingly. An enhancement of the amplified spontaneous emission was observed close to the band edge, where light is slowed down...

  5. Liquid crystal tunable photonic crystal dye laser

    Buss, Thomas; Christiansen, Mads Brøkner; Smith, Cameron;

    2010-01-01

    We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium.......We present a dye-doped liquid crystal laser using a photonic crystal cavity. An applied electric field to the liquid crystal provides wavelength tunability. The photonic crystal enhances resonant interaction with the gain medium....

  6. Fractal Photonic Crystal Waveguides

    Monsoriu, Juan A.; Zapata-Rodriguez, Carlos J.; Silvestre, Enrique; Furlan, Walter D.

    2004-01-01

    We propose a new class of one-dimensional (1D) photonic waveguides: the fractal photonic crystal waveguides (FPCWs). These structures are photonic crystal waveguides (PCWs) etched with fratal distribution of grooves such as Cantor bars. The transmission properties of the FPCWs are investigated and compared with those of the conventional 1D PCWs. It is shown that the FPCW transmission spectrum has self-similarity properties associated with the fractal distribution of grooves. Furthermore, FPCW...

  7. Ultrafast photonic crystal optical switching

    GONG Qi-huang; HU Xiao-yong

    2006-01-01

    Photonic crystal,a novel and artificial photonic material with periodic dielectric distribution,possesses photonic bandgap and can control the propagation states of photons.Photonic crystal has been considered to be a promising candidate for the future integrated photonic devices.The properties and the fabrication method of photonic crystal are expounded.The progresses of the study of ultrafast photonic crystal optical switching are discussed in detail.

  8. Hybrid 2D photonic crystal-assisted Lu3Al5O12:Ce ceramic-plate phosphor and free-standing red film phosphor for white LEDs with high color-rendering index.

    Park, Hoo Keun; Oh, Ji Hye; Kang, Heejoon; Zhang, Jian; Do, Young Rag

    2015-03-01

    This paper reports the combined optical effects of a two-dimensional (2D) SiNx photonic crystal layer (PCL)-assisted Lu3Al5O12:Ce (LuAG:Ce) green ceramic-plate phosphor (CPP) and a free-standing (Sr,Ca)AlSiN3:Eu red film phosphor to enhance luminous efficacy, color rendering index (CRI), and special CRI (R9) of LuAG:Ce CPP-capped white light-emitting diodes (LEDs) for high-power white LEDs at 350 mA. By introducing the 2D SiNx PCL, the luminous efficacy was improved by a factor of 1.25 and 1.15 compared to that of the conventional flat CPP-capped LED and the thickness-increased CPP-capped LED (with a thickness of 0.15 mm), respectively, while maintaining low color-rendering properties. The combining of the free-standing red film phosphor in the flat CPP-capped, the 2D PCL-assisted CPP-capped, and the thickness-increased CPP-capped LEDs led to enhancement of the CRI and the special CRI (R9); it also led to a decrease of the correlated color temperature (CCT) due to broad wavelength coverage via the addition of red emission. High CRI (94), natural white CCT (4450 K), and acceptable luminous efficacy (71.1 lm/W) were attained from the 2D PCL-assisted LuAG:Ce CPP/free-standing red film phosphor-based LED using a red phosphor concentration of 7.5 wt %. It is expected that the combination of the 2D PCL and the free-standing red film phosphor will be a good candidate for achieving a high-power white CPP-capped LED with excellent CRI. PMID:25675264

  9. Photonic Crystal Fibres

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    bandgap structures and thoughts of inspiration from microstructures in nature, as well as classification of the various photonic crystal fibres, theoretical tools for analysing the fibres and methods of their production. Finally, the book points toward some of the many future applications, where photonic...

  10. 2D materials for photon conversion and nanophotonics

    Tahersima, Mohammad H.; Sorger, Volker J.

    2015-09-01

    The field of two-dimensional (2D) materials has the potential to enable unique applications across a wide range of the electromagnetic spectrum. While 2D-layered materials hold promise for next-generation photon-conversion intrinsic limitations and challenges exist that shall be overcome. Here we discuss the intrinsic limitations as well as application opportunities of this new class of materials, and is sponsored by the NSF program Designing Materials to Revolutionize and Engineer our Future (DMREF) program, which links to the President's Materials Genome Initiative. We present general material-related details for photon conversion, and show that taking advantage of the mechanical flexibility of 2D materials by rolling MoS2/graphene/hexagonal boron nitride stack to a spiral solar cell allows for solar absorption up to 90%.

  11. Main Factors for Affecting Photonic Bandgap of Photonic Crystals

    LI Xia; XUE Wei; JIANG Yu-rong; YU Zhi-nong; WANG Hua-qing

    2007-01-01

    The factors affecting one dimensional (1D) and two dimensional (2D) photonic crystals (PhCs) are systemically analyzed in this paper by numerical simulation.Transfer matrix method (TMM) is employed for 1D PCs, both finite difference time domain method (FDTD) and plane wave expansion method (PWE) are employed for 2D PCs.The result shows that the photonic bandgaps (PBG) are directly affected by crystal type, crystal lattice constant, modulation of refractive index and periodicity, and it is should be useful for design of different type photonic crystals with the required PBG and functional devices.Finally, as an example, a near-IR 1D PCs narrow filter was designed.

  12. Photonic crystal laser-driven accelerator structures

    Cowan, Benjamin

    2005-01-01

    We discuss simulated photonic crystal structure designs, including two- and three-dimensional planar structures and fibers. The discussion of 2D structures demonstrates guiding of a speed-of-light accelerating mode by a defect in a photonic crystal lattice and reveals design considerations and trade-offs. With a three-dimensional lattice, we introduce a candidate geometry and discuss beam dynamics, coupling, and manufacturing techniques for that structure. In addition we discuss W-band scale tests of photonic crystal structures. The computational methods are also discussed.

  13. 2D and 3D heterogeneous photonic integrated circuits

    Yoo, S. J. Ben

    2014-03-01

    Exponential increases in the amount of data that need to be sensed, communicated, and processed are continuing to drive the complexity of our computing, networking, and sensing systems. High degrees of integration is essential in scalable, practical, and cost-effective microsystems. In electronics, high-density 2D integration has naturally evolved towards 3D integration by stacking of memory and processor chips with through-silicon-vias. In photonics, too, we anticipate highdegrees of 3D integration of photonic components to become a prevailing method in realizing future microsystems for information and communication technologies. However, compared to electronics, photonic 3D integration face a number of challenges. This paper will review two methods of 3D photonic integration --- fs laser inscription and layer stacking, and discuss applications and future prospects.

  14. Cooperative dynamics in ultrasoft 2D crystals

    Sprakel, Joris; van der Meer, Berend; Dijkstra, Marjolein; van der Gucht, Jasper

    2015-03-01

    The creation, annihilation, and diffusion of defects in crystal lattices play an important role during crystal melting and deformation. Although it is well understood how defects form and react when crystals are subjected to external stresses, it remains unclear how crystals cope with internal stresses. We report a study in which we create a highly localized internal stress, by means of optical tweezing, in a crystal formed from micrometer-sized colloidal spheres and directly observe how the solid reacts using microscopy. We find that, even though the excitation is highly localized, a collective dance of colloidal particles results; these collective modes take the form of closed rings or open-ended strings, depending on the sequence of events which nucleate the rearrangements. Surprisingly, we find from Brownian Dynamics simulations that these cooperative dynamics are thermally-activated modes inherent to the crystal, and can even occur through a single, sufficiently large thermal fluctuation, resulting in the irreversible displacement of 100s of particles from their lattice sites.

  15. Photonic Crystals Towards Nanoscale Photonic Devices

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

    2005-01-01

    Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

  16. Photonic Crystals Towards Nanoscale Photonic Devices

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

    2008-01-01

    Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

  17. Nonlinear Photonic Crystal Fibers

    Hansen, Kim Per

    2004-01-01

    applications based on four-wave mixing. In addition, the broad supercontinua have a range of applications within biomedicine, telecommunication and metrology. The special structure of photonic crystal fibers opens up the possibility, in a simple way, to create polarization-maintaining fibers without the use of...

  18. Photonic Crystal Fibers

    William J. Wadsworth; Jonathan C. Knight; William H. Reeves; Philip St.J. Russell

    2003-01-01

    By offering greatly enhanced control of light compared to conventional step-index structures, photonic crystal fibres are radically improving the performance of linear and nonlinear fibre devices, including gas-Raman cells, super-continuum generators, soliton systems and cladding-pumped lasers.

  19. Photonic Crystal VCSELs

    D.; S.; Song; J.; W.; Paek; K.; H.; Lee; Y.; H.; Lee

    2003-01-01

    Photonic crystal vertical cavity surface emitting lasers (PC VCSELs) are reviewed. The PC VCSEL shows single-transverse-mode continuous wave operation in the entire current range with side mode suppression ratio 35-40 dB. A simple 3-D plane wave expansion method is found to be very effective in analyzing the modal properties of the PC VCSELs.

  20. Photonic Crystal VCSELs

    D. S. Song; J. W. Paek; K. H. Lee; Y. H. Lee

    2003-01-01

    Photonic crystal vertical cavity surface emitting lasers (PC VCSELs) are reviewed. The PC VCSEL shows single-transverse-mode continuous wave operation in the entire current range with side mode suppression ratio 35-40dB. A simple 3-D plane wave expansion method is found to be very effective in analyzing the modal properties of the PC VCSELs.

  1. Quantum dot photonic crystal lasers

    Yoshie, T.; Shchekin, O. B.; Chen, H.; Deppe, D. G.; Scherer, A.

    2002-01-01

    Coupled cavity designs on two-dimensional square lattice photonic crystal slabs were used to demonstrate optically pumped indium arsenide quantum dot photonic crystal lasers at room temperature. Threshold pump powers of 120 and 370 μW were observed for coupled cavities including two and four defect cavities defined in optimised photonic crystals.

  2. Nano-scale electronic and optoelectronic devices based on 2D crystals

    Zhu, Wenjuan

    In the last few years, the research community has been rapidly growing interests in two-dimensional (2D) crystals and their applications. The properties of these 2D crystals are diverse -- ranging from semi-metal such as graphene, semiconductors such as MoS2, to insulator such as boron nitride. These 2D crystals have many unique properties as compared to their bulk counterparts due to their reduced dimensionality and symmetry. A key difference is the band structures, which lead to distinct electronic and photonic properties. The 2D nature of the material also plays an important role in defining their exceptional properties of mechanical strength, surface sensitivity, thermal conductivity, tunable band-gap and their interaction with light. These unique properties of 2D crystals open up a broad territory of applications in computing, communication, energy, and medicine. In this talk, I will present our work on understanding the electrical properties of graphene and MoS2, in particular current transport and band-gap engineering in graphene, interface between gate dielectrics and graphene, and gap states in MoS2. I will also present our work on the nano-scale electronic devices (RF and logic devices) and photonic devices (plasmonic devices and photo-detectors) based on these 2D crystals.

  3. Creating bio-inspired hierarchical 3D-2D photonic stacks via planar lithography on self-assembled inverse opals

    Burgess, Ian B; Loncar, Marko

    2012-01-01

    Structural hierarchy and complex 3D architecture are characteristics of biological photonic designs that are challenging to reproduce in synthetic materials. Top-down lithography allows for designer patterning of arbitrary shapes, but is largely restricted to planar 2D structures. Self-assembly techniques facilitate easy fabrication of 3D photonic crystals, but controllable defect-integration is difficult. In this paper we combine the advantages of top-down and bottom-up fabrication, developing two techniques to deposit 2D-lithographically-patterned planar layers on top of or in between inverse-opal 3D photonic crystals and creating hierarchical structures that resemble the architecture of the bright green wing scales of the butterfly, Parides sesostris. These fabrication procedures, combining advantages of both top-down and bottom-up fabrication, may prove useful in the development of omnidirectional coloration elements and 3D-2D photonic crystal devices.

  4. Creating bio-inspired hierarchical 3D–2D photonic stacks via planar lithography on self-assembled inverse opals

    Structural hierarchy and complex 3D architecture are characteristics of biological photonic designs that are challenging to reproduce in synthetic materials. Top–down lithography allows for designer patterning of arbitrary shapes, but is largely restricted to planar 2D structures. Self-assembly techniques facilitate easy fabrication of 3D photonic crystals, but controllable defect-integration is difficult. In this paper we combine the advantages of top–down and bottom–up fabrication, developing two techniques to deposit 2D-lithographically-patterned planar layers on top of or in between inverse-opal 3D photonic crystals and creating hierarchical structures that resemble the architecture of the bright green wing scales of the butterfly, Parides sesostris. These fabrication procedures, combining advantages of both top–down and bottom–up fabrication, may prove useful in the development of omnidirectional coloration elements and 3D–2D photonic crystal devices. (paper)

  5. Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides

    Mak, Kin Fai; Shan, Jie

    2016-04-01

    Recent advances in the development of atomically thin layers of van der Waals bonded solids have opened up new possibilities for the exploration of 2D physics as well as for materials for applications. Among them, semiconductor transition metal dichalcogenides, MX2 (M = Mo, W; X = S, Se), have bandgaps in the near-infrared to the visible region, in contrast to the zero bandgap of graphene. In the monolayer limit, these materials have been shown to possess direct bandgaps, a property well suited for photonics and optoelectronics applications. Here, we review the electronic and optical properties and the recent progress in applications of 2D semiconductor transition metal dichalcogenides with emphasis on strong excitonic effects, and spin- and valley-dependent properties.

  6. Photonic Crystal Optical Tweezers

    Wilson, Benjamin K.; Mentele, Tim; Bachar, Stephanie; Knouf, Emily; Bendoraite, Ausra; Tewari, Muneesh; Pun, Suzie H.; Lin, Lih Y.

    2009-01-01

    Non-invasive optical manipulation of particles has emerged as a powerful and versatile tool for biological study and nanotechnology. In particular, trapping and rotation of cells, cell nuclei and sub-micron particles enables unique functionality for various applications such as tissue engineering, cancer research and nanofabrication. We propose and demonstrate a purely optical approach to rotate and align particles using the interaction of polarized light with photonic crystal nanostructures ...

  7. Hydrophobic photonic crystal fibers.

    Xiao, Limin; Birks, T A; Loh, W H

    2011-12-01

    We propose and demonstrate hydrophobic photonic crystal fibers (PCFs). A chemical surface treatment for making PCFs hydrophobic is introduced. This repels water from the holes of PCFs, so that their optical properties remain unchanged even when they are immersed in water. The combination of a hollow core and a water-repellent inner surface of the hydrophobic PCF provides an ultracompact dissolved-gas sensor element, which is demonstrated for the sensing of dissolved ammonia gas. PMID:22139276

  8. Variable frequency photonic crystals

    Wu, Xiang-Yao; Liu, Xiao-Jing; Yang, Jing-Hai; Li, Hong; Chen, Wan-Jin

    2015-01-01

    In this paper, we have firstly proposed a new one-dimensional variable frequency photonic crystals (VFPCs), and calculated the transmissivity and the electronic field distribution of VFPCs with and without defect layer, and considered the effect of defect layer and variable frequency function on the transmissivity and the electronic field distribution. We have obtained some new characteristics for the VFPCs, which should be help to design a new type optical devices.

  9. Graphene-based photonic crystal

    Berman, Oleg L.; Boyko, Vladimir S.; Kezerashvili, Roman Ya.; Kolesnikov, Anton A.; Lozovik, Yurii E.

    2010-01-01

    A novel type of photonic crystal formed by embedding a periodic array of constituent stacks of alternating graphene and dielectric discs into a background dielectric medium is proposed. The photonic band structure and transmittance of such photonic crystal are calculated. The graphene-based photonic crystals can be used effectively as the frequency filters and waveguides for the far infrared region of electromagnetic spectrum. Due to substantial suppression of absorption of low-frequency radi...

  10. Slotted Photonic Crystal Sensors

    Andrea Di Falco

    2013-03-01

    Full Text Available Optical biosensors are increasingly being considered for lab-on-a-chip applications due to their benefits such as small size, biocompatibility, passive behaviour and lack of the need for fluorescent labels. The light guiding mechanisms used by many of them results in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This review article presents a new platform for optical biosensors, namely slotted photonic crystals, which provide higher sensitivities due to their ability to confine, spatially and temporally, the optical mode peak within the analyte itself. Loss measurements showed values comparable to standard photonic crystals, confirming their ability to be used in real devices. A novel resonant coupler was designed, simulated, and experimentally tested, and was found to perform better than other solutions within the literature. Combining with cavities, microfluidics and biological functionalization allowed proof-of-principle demonstrations of protein binding to be carried out. Higher sensitivities were observed in smaller structures than possible with most competing devices reported in the literature. This body of work presents slotted photonic crystals as a realistic platform for complete on-chip biosensing; addressing key design, performance and application issues, whilst also opening up exciting new ideas for future study.

  11. Photonic Crystal Optical Tweezers

    Wilson, Benjamin K; Bachar, Stephanie; Knouf, Emily; Bendoraite, Ausra; Tewari, Muneesh; Pun, Suzie H; Lin, Lih Y

    2009-01-01

    Non-invasive optical manipulation of particles has emerged as a powerful and versatile tool for biological study and nanotechnology. In particular, trapping and rotation of cells, cell nuclei and sub-micron particles enables unique functionality for various applications such as tissue engineering, cancer research and nanofabrication. We propose and demonstrate a purely optical approach to rotate and align particles using the interaction of polarized light with photonic crystal nanostructures to generate enhanced trapping force. With a weakly focused laser beam we observed efficient trapping and transportation of polystyrene beads with sizes ranging from 10 um down to 190 nm as well as cancer cell nuclei. In addition, we demonstrated alignment of non-spherical particles using a 1-D photonic crystal structure. Bacterial cells were trapped, rotated and aligned with optical intensity as low as 17 uW/um^2. Finite-difference time domain (FDTD) simulations of the optical near-field and far-field above the photonic c...

  12. Photonic Crystal Slab Quantum Well Infrared Photodetector

    Full text: Photonic crystals (PCs) exhibit fascinating properties for the control of light. Two-dimensional (2D) PCs are the most important class, as they are compatible with standard semiconductor processing. For confinement of photons in the out-of-plane direction a photonic crystal slab (PCS) is often used. By fabricating a PCS from a photosensitive material the resonant modes of the PCS can be directly measured in the photocurrent spectrum of the device. For detection of light in the mid-infrared region (MIR) we used a quantum well infrared photodetector (QWIP). At the resonance frequencies of the PCS the lifetime of the photons is increased, which increases the photon absorption. Therefore, a lower doping concentration in the quantum wells of the active zone can be used. With a lower doping concentration the thermal noise is reduced and maximum operation temperature can be increased. (author)

  13. Natural photonic crystals

    Vigneron, Jean Pol; Simonis, Priscilla

    2012-10-01

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  14. Natural photonic crystals

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  15. Natural photonic crystals

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  16. Resonant Photonic States in Coupled Heterostructure Photonic Crystal Waveguides

    Sabarinathan J; Cox JD; Singh

    2010-01-01

    Abstract In this paper, we study the photonic resonance states and transmission spectra of coupled waveguides made from heterostructure photonic crystals. We consider photonic crystal waveguides made from three photonic crystals A, B and C, where the waveguide heterostructure is denoted as B/A/C/A/B. Due to the band structure engineering, light is confined within crystal A, which thus act as waveguides. Here, photonic crystal C is taken as a nonlinear photonic crystal, which has a band gap th...

  17. Photonic crystals in epitaxial semiconductors

    La Rue, R M de

    1998-01-01

    The title of the paper uses the expression "photonic crystals". By photonic crystals, we mean regular periodic structures with a substantial refractive index variation in one-, two- or three- dimensional space. Such crystals can $9 exist naturally, for example natural opal, but are more typically fabricated by people. Under sufficiently strong conditions, i.e., sufficiently large refractive index modulation, correct size of structural components, and $9 appropriate rotational and translational symmetry, these crystals exhibit the characteristics of a photonic bandgap (PBG) structure. In a full photonic bandgap structure there is a spectral stop band for electromagnetic waves $9 propagating in any direction through the structure and with an arbitrary state of polarization. This behavior is of interest both from a fundamental viewpoint and from the point of view of novel applications in photonic devices. The $9 paper gives an outline review of work on photonic crystals carried out by the Optoelectronics Researc...

  18. Photonic-crystal fibers gyroscope

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  19. Glassy dislocation dynamics in 2D colloidal dimer crystals.

    Gerbode, Sharon J; Agarwal, Umang; Ong, Desmond C; Liddell, Chekesha M; Escobedo, Fernando; Cohen, Itai

    2010-08-13

    Although glassy relaxation is typically associated with disorder, here we report on a new type of glassy dynamics relating to dislocations within 2D crystals of colloidal dimers. Previous studies have demonstrated that dislocation motion in dimer crystals is restricted by certain particle orientations. Here, we drag an optically trapped particle through such dimer crystals, creating dislocations. We find a two-stage relaxation response where initially dislocations glide until encountering particles that cage their motion. Subsequent relaxation occurs logarithmically slowly through a second process where dislocations hop between caged configurations. Finally, in simulations of sheared dimer crystals, the dislocation mean squared displacement displays a caging plateau typical of glassy dynamics. Together, these results reveal a novel glassy system within a colloidal crystal. PMID:20868079

  20. Optical tornadoes in photonic crystals

    Onoda, Masaru; Ochiai, Tetsuyuki

    2008-01-01

    Based on an optical analogy of spintronics, the generation of optical tornadoes is theoretically investigated in two-dimensional photonic crystals without space-inversion symmetry. We address its close relation to the Berry curvature in crystal momentum space, which represents the non-trivial geometric property of a Bloch state. It is shown that the Berry curvature is easily controlled by tuning two types of dielectric rods in a honeycomb photonic crystal. Then, Bloch states with large Berry ...

  1. Quasimetallic silicon micromachined photonic crystals

    We report on fabrication of a layer-by-layer photonic crystal using highly doped silicon wafers processed by semiconductor micromachining techniques. The crystals, built using (100) silicon wafers, resulted in an upper stop band edge at 100 GHz. The transmission and defect characteristics of these structures were found to be analogous to metallic photonic crystals. We also investigated the effect of doping concentration on the defect characteristics. The experimental results agree well with predictions of the transfer matrix method simulations

  2. Photonic crystal waveguides in PECVD glass

    Liu, Haoling; Frandsen, Lars Hagedorn; Têtu, Amélie; Borel, Peter Ingo; Fage-Pedersen, Jacob

    Silicon oxynitride (SiON) on silicon has found wide use as a robust and versatileplatform for integrated, optical devices. With plasma-enhanced chemical vapourdeposition (PECVD) the refractive index can be varied all the way from 1.5 (pure silica,SiO2) to 2.0 (pure silicon nitride, Si3N4). We have...... fabricated glasses with refractive indexup to approximately 1.75, with which value it is possible to fabricate photonic crystalwaveguides. These structures have the advantage of being transparent in the whole of thevisible region, which makes them different from photonic crystals made in...... semiconductormaterials, and attractive in, e.g., biological applications. For operation in the visibleregion, the photonic crystal waveguide must be realized with a 2D lattice of air holes thatare spaced with a period of ~ 300 nm. In this poster, we report on simulations of theoptical guiding in these structures and...

  3. Multicolor photonic crystal laser array

    Wright, Jeremy B; Brener, Igal; Subramania, Ganapathi S; Wang, George T; Li, Qiming

    2015-04-28

    A multicolor photonic crystal laser array comprises pixels of monolithically grown gain sections each with a different emission center wavelength. As an example, two-dimensional surface-emitting photonic crystal lasers comprising broad gain-bandwidth III-nitride multiple quantum well axial heterostructures were fabricated using a novel top-down nanowire fabrication method. Single-mode lasing was obtained in the blue-violet spectral region with 60 nm of tuning (or 16% of the nominal center wavelength) that was determined purely by the photonic crystal geometry. This approach can be extended to cover the entire visible spectrum.

  4. Configurable silicon photonic crystal waveguides

    In this Letter, we demonstrate that the mode cut off of a photonic crystal waveguide can be trimmed with high accuracy by electron beam bleaching of a chromophore doped polymer cladding. Using this method, configurable waveguides are realized, which allow for spatially resolved changes of the photonic crystal's effective lattice constant as small as 7.6 pm. We show three different examples how to take advantage of configurable photonic crystal waveguides: Shifting of the complete transmission spectrum, definition of cavities with high quality factor, and tuning of existing cavities

  5. Modeling of photonic Crystal Fibres

    Bjarklev, Anders Overgaard; Broeng, Jes; Barkou, Stig Eigil

    1999-01-01

    Diferent theoretical models for analysis of photonic crystal fibres are reviewed and compaired. The methods span from simple scalar approaches to full-vectorial models using different mode-field decompositions. The specific advantages of the methods are evaluated.......Diferent theoretical models for analysis of photonic crystal fibres are reviewed and compaired. The methods span from simple scalar approaches to full-vectorial models using different mode-field decompositions. The specific advantages of the methods are evaluated....

  6. Photonic Crystal Waveguides in Triangular Lattice of Nanopillars

    Chigrin, Dmitry N.; Lavrinenko, Andrei

    Photonic nanopillars waveguides have been analysed. Dielectric nanopillars are arranged in such way that they from a tringular lattice of 2D photonic crystal. Dispersion of the modes depends on the direction of the triangular lattice, Ã-J or Ã-X, in which nanopillars arrays are extended. Light...

  7. Photonic crystals: features and applications (physics research and technology)

    2013-01-01

    The present book is focused on the study of unprecedented control and manipulation of light by photonic crystals (PCs) and their applications. These are micro- or usually nano-structures composed of periodic indexes of refraction of dielectrics with high refractive index contrast. They exhibit optical frequency band gaps in analogy to electronic bands for a periodic potential of a semiconductor crystal lattice. The gemstone opal and butterflys feathers colours are already referred to as natural examples of photonic crystals. The characteristics of such supper-lattices were first reported by Yablonovitch in 1987. The exploitation of photonic crystals is a promising tool in communication, sensors, optical computing, and nanophotonics. Discussed are the various features of one-dimensional (1D) and two-dimensional (2D) photonic crystals, photonic quasi crystals, heterostuctures and PC fibres under a variety of conditions using several materials, and metamaterials. It also focuses on the applications of PCs in opt...

  8. Manufacturing method of photonic crystal

    Park, In Sung; Lee, Tae Ho; Ahn, Jin Ho; Biswas, Rana; Constant, Kristen P.; Ho, Kai-Ming; Lee, Jae-Hwang

    2013-01-29

    A manufacturing method of a photonic crystal is provided. In the method, a high-refractive-index material is conformally deposited on an exposed portion of a periodic template composed of a low-refractive-index material by an atomic layer deposition process so that a difference in refractive indices or dielectric constants between the template and adjacent air becomes greater, which makes it possible to form a three-dimensional photonic crystal having a superior photonic bandgap. Herein, the three-dimensional structure may be prepared by a layer-by-layer method.

  9. Quantum computation in photonic crystals

    Angelakis, D G; Yannopapas, V; Ekert, A; Angelakis, Dimitris G.; Santos, Marcelo Franca; Yannopapas, Vassilis; Ekert, Artur

    2004-01-01

    Quantum computers require technologies that offer both sufficient control over coherent quantum phenomena and minimal spurious interactions with the environment. We show, that photons confined to photonic crystals, and in particular to highly efficient waveguides formed from linear chains of defects doped with atoms can generate strong non-linear interactions which allow to implement both single and two qubit quantum gates. The simplicity of the gate switching mechanism, the experimental feasibility of fabricating two dimensional photonic crystal structures and integrability of this device with optoelectronics offers new interesting possibilities for optical quantum information processing networks.

  10. Diamond based photonic crystal microcavities.

    Tomljenovic-Hanic, S; Steel, M J; de Sterke, C Martijn; Salzman, J

    2006-04-17

    Diamond based technologies offer a material platform for the implementation of qubits for quantum computing. The photonic crystal architecture provides the route for a scalable and controllable implementation of high quality factor (Q) nanocavities, operating in the strong coupling regime for cavity quantum electrodynamics. Here we compute the photonic band structures and quality factors of microcavities in photonic crystal slabs in diamond, and compare the results with those of the more commonly-used silicon platform. We find that, in spite of the lower index contrast, diamond based photonic crystal microcavities can exhibit quality factors of Q=3.0x10(4), sufficient for proof of principle demonstrations in the quantum regime. PMID:19516502

  11. Modelling of photonic crystal fibres

    Knudsen, Erik

    2003-01-01

    In the presenta ph.d. work a theoretical study of aspects of modelling photonic crystal fibres was carried out. Photonic crystal fibres form a class of optical waveguides where guidance is no longer provided by a difference in refractive index between core and cladding. Instead, guidance is...... provided by an arrangement of air-holes running along the length of the fibre. Depending on the geometry of the fibre, the guiding mechanism may be either arising from the formation of a photonic bandgap in the cladding structure (photonic bandgap fibre), or by an effect resembling total internal...... modes in contiguous fibre segments curved at different radii. Overall microbend loss is expressed as a statistical mean of mismatch losses. Extending a well proven, established formula for macrobending losses in stop index fibres, we provide an estimate of macrobend losses in an air-guiding photonic...

  12. Photonic crystal fibers -

    Libori, Stig E. Barkou

    2002-01-01

    possibilities, the thesis will attempot to offer a proof of concept, rather than an in-depth analysis, thus reflecting the present state of the art within the area of micro-structured fibers. Another important sub-class of micro-structured fibers is photonic bandgap fibers. Photonic bandgap fibers are far more......-structured fibers that guide light by simple index effects. However, photonic bandgap fibers offer more radical possibilities, such as core regions with an effective index that is lower than the surrounding effective cladding index one may guide light in air- and dispersion qualities that differ from both those of...

  13. Transient Plasma Photonic Crystals for High-Power Lasers

    Lehmann, G.; Spatschek, K. H.

    2016-06-01

    A new type of transient photonic crystals for high-power lasers is presented. The crystal is produced by counterpropagating laser beams in plasma. Trapped electrons and electrically forced ions generate a strong density grating. The lifetime of the transient photonic crystal is determined by the ballistic motion of ions. The robustness of the photonic crystal allows one to manipulate high-intensity laser pulses. The scheme of the crystal is analyzed here by 1D Vlasov simulations. Reflection or transmission of high-power laser pulses are predicted by particle-in-cell simulations. It is shown that a transient plasma photonic crystal may act as a tunable mirror for intense laser pulses. Generalizations to 2D and 3D configurations are possible.

  14. Pendellösung effect in photonic crystals

    Savo, S.; di Gennaro, E.; Miletto, C.; Andreone, A.; Dardano, P.; Moretti, L.; Mocella, V.

    2008-06-01

    At the exit surface of a photonic crystal, the intensity of the diffracted wave can be periodically modulated, showing a maximum in the "positive" (forward diffracted) or in the "negative" (diffracted) direction, depending on the slab thickness. This thickness dependence is a direct result of the so-called Pendellosung phenomenon, consisting of the periodic exchange inside the crystal of the energy between direct and diffracted beams. We report the experimental observation of this effect in the microwave region at about 14 GHz by irradiating 2D photonic crystal slabs of different thickness and detecting the intensity distribution of the electromagnetic field at the exit surface and inside the crystal itself.

  15. Photonic-crystal waveguide biosensor

    Skivesen, Nina; Têtu, Amélie; Kristensen, Martin;

    2007-01-01

    A photonic-crystal waveguide sensor is presented for biosensing. The sensor is applied for refractive index measurements and detection of protein-concentrations. Concentrations around 10 μg/ml (0.15μMolar) are measured with excellent signal to noise ratio, and a broad, dynamic refractive index...

  16. Overlay Alignment Using Two Photonic Crystals

    Peng, C; Morton, K; Yu, Z; Chou, Stephen Y.; Morton, Keith; Peng, Can; Yu, Zhaoning

    2005-01-01

    In this paper we proposed a novel overlay alignment method using two sets of identical photonic crystals (PhCs). In this method the reflection or transmission spectrum of the two overlaid photonic crystals is measured to help wafer tilt, yaw rotation, and translation aligning. The initial testing results with two 1D photonic crystals and analysis of the alignment accuracy are presented. This method is particularly useful in building photonic crystal stacks with nanoimprint lithography (NIL).

  17. Optical echo in photonic crystals

    Antipov, A E

    2006-01-01

    The dynamics of photonic wavepacket in the effective oscillator potential is studied. The oscillator potential is constructed on a base of one dimensional photonic crystal with a period of unit cell adiabatically varied in space. The structure has a locally equidistant discrete spectrum. This leads to an echo effect, i.e. the periodical reconstruction of the packet shape. The effect can be observed in a nonlinear response of the system. Numerical estimations for porous-silicon based structures are presented for femtosecond Ti:Sapphire laser pump.

  18. Tunable Photonic Band Gaps In Photonic Crystal Fibers Filled With a Cholesteric Liquid Crystal

    Thomas; Tanggaard; Larsen; David; Sparre; Hermann; Anders; Bjarklev

    2003-01-01

    A photonic crystal fiber has been filled with a cholesteric liquid crystal. A temperature sensitive photonic band gap effect was observed, which was especially pronounced around the liquid crystal phase transition temperature.

  19. FABRICATION OF PHOTONIC CRYSTAL WITH SUPERLATTICES

    SUN Cheng; Chen Haihua; Zhang Jizhong; Wei Hongmei; Gu Zhongze

    2006-01-01

    A novel technique was used to fabricate three-dimensional photonic crystals with superlattices. The super structure was fabricated by assembling monodispersed microspheres in the grooves of the scales of morpho butterfly, which makes the photonic crystal being composed of two kinds of different photonic structures (natural groove structure of butterfly wing and artificial microspherical colloids arrangement). The superstructural photonic crystal exhibits some unique optical properties different from both the butterfly wing and the colloidal crystal. The approach exhibited here provides a new way for fabricate photonic crystals with superlattices.

  20. Two-dimensional function photonic crystals

    Wu, Xiang-Yao; Liu, Xiao-Jing; Liang, Yu

    2016-01-01

    In this paper, we have firstly proposed two-dimensional function photonic crystals, which the dielectric constants of medium columns are the functions of space coordinates $\\vec{r}$, it is different from the two-dimensional conventional photonic crystals constituting by the medium columns of dielectric constants are constants. We find the band gaps of two-dimensional function photonic crystals are different from the two-dimensional conventional photonic crystals, and when the functions form of dielectric constants are different, the band gaps structure should be changed, which can be designed into the appropriate band gaps structures by the two-dimensional function photonic crystals.

  1. Optical Magnetometer Incorporating Photonic Crystals

    Kulikov, Igor; Florescu, Lucia

    2007-01-01

    According to a proposal, photonic crystals would be used to greatly increase the sensitivities of optical magnetometers that are already regarded as ultrasensitive. The proposal applies, more specifically, to a state-of-the-art type of quantum coherent magnetometer that exploits the electromagnetically-induced-transparency (EIT) method for determining a small change in a magnetic field indirectly via measurement of the shift, induced by that change, in the hyperfine levels of resonant atoms exposed to the field.

  2. Photonic crystals, amorphous materials, and quasicrystals

    Photonic crystals consist of artificial periodic structures of dielectrics, which have attracted much attention because of their wide range of potential applications in the field of optics. We may also fabricate artificial amorphous or quasicrystalline structures of dielectrics, i.e. photonic amorphous materials or photonic quasicrystals. So far, both theoretical and experimental studies have been conducted to reveal the characteristic features of their optical properties, as compared with those of conventional photonic crystals. In this article, we review these studies and discuss various aspects of photonic amorphous materials and photonic quasicrystals, including photonic band gap formation, light propagation properties, and characteristic photonic states. (focus issue)

  3. Algorithms and technologies for photonic crystal modelling

    Hart, Elizabeth E.

    2009-01-01

    In this thesis an investigation into the behaviour of light when passing through photonic crystals was carried out using numerical methods. Photonic crystals are expensive and difficult to fabricate so there is a requirement for computer simulations that can quickly and accurately model how the crystal structure will affect the behaviour of light. A finite difference method was written to model two-dimensional photonic crystals. The results from the finite difference method mod...

  4. Heat Treatment of the Photonic Crystal Fiber

    Joo; Beom; Eom; Seongwoo; Yoo; Jinchae; Kim; Hokyung; Kim; Un-Chul; Paek; Byeong; Ha; Lee

    2003-01-01

    We report heat treatment of the photonic crystal fiber. As the temperature was increased, the transmission of the photonic crystal fiber was increased, unlike conventional single mode fiber. The transmission increase at short wavelength region was larger than long wavelength region for the various temperatures. After crystallization of the silica glass, the spectra of the photonic crystal fiber were just decreased at all wavelength regions, but, in case of the single mode fiber, the absorption in visibl...

  5. Photon Polarization in Photonic Crystal Fibers under Compton Scattering

    HAO Dong-shan; ZHANG Xiao-fu

    2007-01-01

    Using the quantum invariant theory and unitary transformation means, we study the influences of multi-photon nonlinear Compton scattering on the photon polarization in photonic crystal fibers(PCF). The results show that the photon polarization of the incident photon changes a lot due to scattered optical, and its general geometric phase factor, Hamiton number and evolution operator are definited both by the incident and scattered optical.

  6. Cholesteric liquid crystal photonic crystal lasers and photonic devices

    Zhou, Ying

    This dissertation discusses cholesteric liquid crystals (CLCs) and polymers based photonic devices including one-dimensional (1D) photonic crystal lasers and broadband circular polarizers. CLCs showing unique self-organized chiral structures have been widely used in bistable displays, flexible displays, and reflectors. However, the photonic band gap they exhibit opens a new way for generating laser light at the photonic band edge (PBE) or inside the band gap. When doped with an emissive laser dye, cholesteric liquid crystals provide distributed feedback so that mirrorless lasing is hence possible. Due to the limited surface anchoring, the thickness of gain medium and feedback length is tens of micrometers. Therefore lasing efficiency is quite limited and laser beam is highly divergent. To meet the challenges, we demonstrated several new methods to enhance the laser emission while reducing the beam divergence from a cholesteric liquid crystal laser. Enhanced laser emission is demonstrated by incorporating a single external CLC reflector as a polarization conserved reflector. Because the distributed feedback from the active layer is polarization selective, a CLC reflector preserves the original polarization of the reflected light and a further stimulated amplification ensues. As a result of virtually doubled feedback length, the output is dramatically enhanced in the same circular polarization state. Meanwhile, the laser beam divergence is dramatically reduced due to the increased cavity length from micrometer to millimeter scale. Enhanced laser emission is also demonstrated by the in-cell metallic reflector because the active layer is pumped twice. Unlike a CLC reflector, the output from a mirror-reflected CLC laser is linearly polarized as a result of coherent superposition of two orthogonal circular polarization states. The output linear polarization direction can be well controlled and fine tuned by varying the operating temperature and cell gap. Enhanced laser

  7. Photonic crystals with topological defects

    Liew, Seng Fatt; Xiong, Wen; Cao, Hui

    2014-01-01

    We introduce topological defect to a square lattice of elliptical cylinders. Despite the broken translational symmetry, the long-range positional order of the cylinders leads to residual photonic bandgap in the density of optical states. However, the band-edge modes are strongly modified by the spatial variation of ellipse orientation. The $\\Gamma-X$ band-edge mode splits into four regions of high intensity and the output flux becomes asymmetric due to the formation of crystalline domains with different orientation. The $\\Gamma-M$ band-edge mode has the energy flux circulates around the topological defect center, creating an optical vortex. By removing the elliptical cylinders at the center, we create localized defect states which are dominated by either clockwise or counter-clockwise circulating waves. The flow direction can be switched by changing the ellipse orientation. The deterministic aperiodic variation of the unit cell orientation adds another dimension to the control of light in photonic crystals, e...

  8. Photonic Crystals: Physics and Technology

    Sibilia, Concita; Marciniak, Marian; Szoplik, Tomasz

    2008-01-01

    The aim of the work is give an overview of the activity in the field of Photonic Crystal developed in the frame of COST P11 action . The main objective of the COST P11 action was to unify and coordinate national efforts aimed at studying linear and nonlinear optical interactions with Photonic Crystals (PCs), without neglecting an important aspect related to the material research as idea and methods of realizations of 3D PC, together with the development and implementation of measurement techniques for the experimental evaluation of their potential applications in different area, as for example telecommunication with novel optical fibers, lasers, nonlinear multi-functionality, display devices , opto-electronics, sensors. The book contain contributions from authors who gave their lecture at the Cost P11 Training School. Training School was held at the Warsaw University (2007) and National Institute of Telecommunications (May 23), Warsaw. It was attended by 23 students. The focus of the School was on the work of...

  9. Biased liquid crystal photonic bandgap fiber

    Weirich, Johannes; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard;

    2008-01-01

    We simulate the director structure of all capillaries in a biased photonic crystal fiber infiltrated with liquid crystals. Various mode simulations for different capillaries show the necessity to consider the entire structure.......We simulate the director structure of all capillaries in a biased photonic crystal fiber infiltrated with liquid crystals. Various mode simulations for different capillaries show the necessity to consider the entire structure....

  10. Spatial solitons in nonlinear photonic crystals

    Corney, Joel Frederick; Bang, Ole

    2000-01-01

    We study solitons in one-dimensional quadratic nonlinear photonic crystals with periodic linear and nonlinear susceptibilities. We show that such crystals support stable bright and dark solitons, even when the effective quadratic nonlinearity is zero.......We study solitons in one-dimensional quadratic nonlinear photonic crystals with periodic linear and nonlinear susceptibilities. We show that such crystals support stable bright and dark solitons, even when the effective quadratic nonlinearity is zero....

  11. On the effective shear speed in 2D phononic crystals

    Kutsenko, A A; Norris, A N; Poncelet, O

    2011-01-01

    The quasistatic limit of the antiplane shear-wave speed ('effective speed') $c$ in 2D periodic lattices is studied. Two new closed-form estimates of $c$ are derived by employing two different analytical approaches. The first proceeds from a standard background of the plane wave expansion (PWE). The second is a new approach, which resides in $\\mathbf{x}$-space and centers on the monodromy matrix (MM) introduced in the 2D case as the multiplicative integral, taken in one coordinate, of a matrix with components being the operators with respect to the other coordinate. On the numerical side, an efficient PWE-based scheme for computing $c$ is proposed and implemented. The analytical and numerical findings are applied to several examples of 2D square lattices with two and three high-contrast components, for which the new PWE and MM estimates are compared with the numerical data and with some known approximations. It is demonstrated that the PWE estimate is most efficient in the case of densely packed stiff inclusio...

  12. Extraordinary wavelength reduction in terahertz graphene-cladded photonic crystal slabs

    Williamson, Ian A D; Wang, Zheng

    2015-01-01

    Photonic crystal slabs have been widely used in nanophotonics for light confinement, dispersion engineering, nonlinearity enhancement, and other unusual effects arising from their structural periodicity. Sub-micron device sizes and mode volumes are routine for silicon-based photonic crystal slabs, however spectrally they are limited to operate in the near infrared. Here, we show that two single-layer graphene sheets allow silicon photonic crystal slabs with submicron periodicity to operate in the terahertz regime, with an extreme 100x wavelength reduction and excellent out-of-plane confinement. The graphene-cladded photonic crystal slabs exhibit band structures closely resembling those of ideal two-dimensional photonic crystals, with broad two-dimensional photonic band gaps even when the slab thickness approaches zero. The overall photonic band structure not only scales with the graphene Fermi level, but more importantly scales to lower frequencies with reduced slab thickness. Just like ideal 2D photonic crys...

  13. Topologically robust transport of entangled photons in a 2D photonic system

    Mittal, Sunil; Hafezi, Mohammad

    2016-01-01

    We theoretically study transport of time-bin entangled photon pairs in a two-dimensional topological photonic system of coupled ring resonators. This system implements the integer quantum Hall model using a synthetic gauge field and exhibits topologically robust edge states. We show that the topological edge states provide a robust channel for on-chip quantum communication when the information is encoded in temporal correlations of photons. In contrast to edge states, transport through bulk states does not preserve these correlations and can lead to significant unwanted temporal bunching or anti-bunching of photons. We also compare the transport of entangled two-photon states to separable two-photon states and show that the entangled states are more fragile. Furthermore, we study the effect of disorder on the quantum transport properties; while the edge transport remains robust, bulk transport is very susceptible, and in the limit of strong disorder, bulk states become localized. We show that this localizatio...

  14. PLANAR OPTICAL WAVEGUIDES WITH PHOTONIC CRYSTAL STRUCTURE

    2003-01-01

    Planar optical waveguide comprising a core region and a cladding region comprising a photonic crystal material, said photonic crystal material having a lattice of column elements, wherein at least a number of said column elements are elongated substantially in an axial direction for said core...

  15. Numerical analysis of multicore photonic crystal fibers

    Yanfeng Li(栗岩锋); Qingyue Wang(王清月); Minglie Hu(胡明列)

    2003-01-01

    A Galerkin's method-based numerical procedure is extended to obtain the modal field distribution ofmulticore photonic crystal fibers for the first time to our knowledge, which can reveal how the air hole sizeinfluences the mode coupling and how the coupling strength varies with wavelength. These results will behelpful in the future design of multicore photonic crystal fibers with proper guidance properties.

  16. Optical experiments on 3D photonic crystals

    Koenderink, F.; Vos, W.

    2003-01-01

    Photonic crystals are optical materials that have an intricate structure with length scales of the order of the wavelength of light. The flow of photons is controlled in a manner analogous to how electrons propagate through semiconductor crystals, i.e., by Bragg diffraction and the formation of band

  17. Photonic crystal fiber based antibody detection

    Duval, A; Lhoutellier, M; Jensen, J B; Hoiby, P E; Missier, V; Pedersen, L H; Hansen, Theis Peter; Bjarklev, Anders Overgaard; Bang, Ole

    An original approach for detecting labeled antibodies based on strong penetration photonic crystal fibers is introduced. The target antibody is immobilized inside the air-holes of a photonic crystal fiber and the detection is realized by the means of evanescent-wave fluorescence spectroscopy and...

  18. Photonic crystal scintillators and methods of manufacture

    Torres, Ricardo D.; Sexton, Lindsay T.; Fuentes, Roderick E.; Cortes-Concepcion, Jose

    2015-08-11

    Photonic crystal scintillators and their methods of manufacture are provided. Exemplary methods of manufacture include using a highly-ordered porous anodic alumina membrane as a pattern transfer mask for either the etching of underlying material or for the deposition of additional material onto the surface of a scintillator. Exemplary detectors utilizing such photonic crystal scintillators are also provided.

  19. Photonic Paint Developed with Metallic Three-Dimensional Photonic Crystals

    John D. Williams

    2012-07-01

    Full Text Available This work details the design and simulation of an inconspicuous photonic paint that can be applied onto an object for anticounterfeit and tag, track, and locate (TTL applications. The paint consists of three-dimensional metallic tilted woodpile photonic crystals embedded into a visible and infrared transparent polymer film, which can be applied to almost any surface. The tilted woodpile photonic crystals are designed with a specific pass band detectable at nearly all incident angles of light. When painted onto a surface, these crystals provide a unique reflective infra-red optical signature that can be easily observed and recorded to verify the location or contents of a package.

  20. Surface states in photonic crystals

    Vojtíšek P.

    2013-05-01

    Full Text Available Among many unusual and interesting physical properties of photonic crystals (PhC, in recent years, the propagation of surface electromagnetic waves along dielectric PhC boundaries have attracted considerable attention, also in connection to their possible applications. Such surfaces states, produced with the help of specialized defects on PhC boundaries, similarly to surfaces plasmons, are localized surfaces waves and, as such, can be used in various sensing applications. In this contribution, we present our recent studies on numerical modelling of surface states (SS for all three cases of PhC dimensionality. Simulations of these states were carried out by the use of plane wave expansion (PWE method via the MIT MPB package.

  1. Heat Treatment of the Photonic Crystal Fiber

    Joo Beom Eom; Seongwoo Yoo; Jinchae Kim; Hokyung Kim; Un-Chul Paek; Byeong Ha Lee

    2003-01-01

    We report heat treatment of the photonic crystal fiber. As the temperature was increased, the transmission of the photonic crystal fiber was increased, unlike conventional single mode fiber. The transmission increase at short wavelength region was larger than long wavelength region for the various temperatures. After crystallization of the silica glass, the spectra of the photonic crystal fiber were just decreased at all wavelength regions, but, in case of the single mode fiber, the absorption in visible region around 450 nm increased with increasing temperature.

  2. Liquid crystal orientation control in photonic liquid crystal fibers

    Chychlowski, M. S.; Nowinowski-Kruszelnicki, E.; Woliński, T. R.

    2011-05-01

    Similarly to liquid crystal displays technology in photonic liquid crystal fibers (PLCFs) a molecular orientation control is a crucial issue that influences proper operation of PLCF-based devices. The paper presents two distinct configurations: planar and radial escaped orientation of the LC molecules inside capillaries as well as methods of their application to photonic liquid crystal fibers. Possibilities of LC orientation control influence both: attenuation and transmitting spectra of the PLCF The orienting method is based on creation of an additional orienting layer on the inner surface of the capillary or air hole of the photonic liquid crystal fiber. Aligning materials used in the experiment are commercially available polyimides SE1211 and SE130 which induce liquid crystal homeotropic and planar anchoring conditions. The orienting layer increase an order parameter of the liquid crystal improving propagation properties and stability of photonic liquid crystal fiber-based devices.

  3. Biased liquid crystal infiltrated photonic bandgap fiber

    Weirich, Johannes; Lægsgaard, Jesper; Scolari, Lara;

    2009-01-01

    A simulation scheme for the transmission spectrum of a photonic crystal fiber infiltrated with a nematic liquid crystal and subject to an external bias is presented. The alignment of the biased liquid crystal is simulated using the finite element method to solve the relevant system of coupled...... partial differential equations. From the liquid crystal alignment the full tensorial dielectric permittivity in the capillaries is derived. The transmission spectrum for the photonic crystal fiber is obtained by solving the generalized eigenvalue problem deriving from Maxwell’s equations using a vector...... element based finite element method. We demonstrate results for a splay aligned liquid crystal infiltrated into the capillaries of a four-ring photonic crystal fiber and compare them to corresponding experiments....

  4. Sidewall roughness measurement of photonic wires and photonic crystals

    Svalgaard, Mikael; Frandsen, Lars Hagedorn; Garnæs, Jørgen;

    2007-01-01

    The performance of nanophotonic building blocks such as photonic wires and photonic crystals are rapidly improving, with very low propagation loss and very high cavity Q-factors being reported. In order to facilitate further improvements in performance the ability to quantitatively measure...

  5. Large-bandwidth planar photonic crystal waveguides

    Søndergaard, Thomas; Lavrinenko, Andrei

    defect has appropriate dispersion properties relative to the photonic crystal slab material surrounding the line defect. A three-dimensional theoretical analysis is given for large-bandwidth waveguide designs based on a silicon-air photonic crystal slab suspended in air. In one example, the leakage......A general design principle is presented for making finite-height photonic crystal waveguides that support leakage-free guidance of light over large frequency intervals. The large bandwidth waveguides are designed by introducing line defects in photonic crystal slabs, where the material in the line......-free single-mode guidance is found for a large frequency interval covering 60% of the photonic band-gap....

  6. Single-photon 2-D imaging X-ray spectrometer employing trapping with four tunnel junctions

    We are developing single-photon 2-D imaging X-ray spectrometers for applications in X-ray astrophysics. The devices employing a Ta strip X-ray absorber with Al traps and a tunnel junction at each end have been tested. They achieve an energy resolution of 26 eV out of 5.9 keV over a limited length (Segall, IEEE Trans., in press) with a 1-D spatial resolution of about 2 μm over the full 160 μm length. By analytical and numerical simulations of the quasiparticle diffusion process, we study related devices with a square Ta absorber having four traps and attached junctions to provide 2-D imaging. The traps give charge division to the corners or to the edges of the square absorber. We find that these devices can give good 2-D spatial resolution. We discuss the operating principle and the factors which affect the spatial resolution

  7. Tuning of resonances in photonic crystal photodetectors

    Full text: Photonic crystal slabs (PCS) have shown capabilities for detectivity enhancement of photodetectors in the mid-infrared region (MIR). The increased photon lifetime at the PCS resonance peaks leads to a higher photon absorption. For tuning of the resonances of a PCS quantum well infrared photodetector we used a device structure, that allows PCS heating by a lateral current flow. It was additionally designed for resonance tuning by postprocessing the PCS thickness. The combination of postprocessing and thermal tuning allows coarse and fine shifting of the photonic crystal resonances. Peakshifts up to 4 cm-1 were achieved by thermal fine tuning at a design wavelength of 8 μm. (author)

  8. Simulation and design of the photonic crystal microwave accelerating structure

    The authors have derived the global band gaps for general two-dimensional (2D) photonic crystal microwave accelerating structures formed by square or triangular arrays of metal posts. A coordinate-space, finite-difference code was used to calculate the complete dispersion curves for the lattices. The fundamental and higher frequency global photonic band gaps were determined numerically. The structure formed by triangular arrays of metal posts with a missing rod at the center has advantages of higher-order-modes (HOM) suppression and main mode restriction under the condition of a/b<0.2. The relationship between the RF properties and the geometrical parameters have been studied for the 9.37 GHz photonic crystal accelerating structure. The Rs, Q, Rs/Q of the new structure may be comparable to the disk-loaded accelerating structure. (authors)

  9. Photonic crystal ring resonator based optical filters for photonic integrated circuits

    In this paper, a two Dimensional (2D) Photonic Crystal Ring Resonator (PCRR) based optical Filters namely Add Drop Filter, Bandpass Filter, and Bandstop Filter are designed for Photonic Integrated Circuits (PICs). The normalized output response of the filters is obtained using 2D Finite Difference Time Domain (FDTD) method and the band diagram of periodic and non-periodic structure is attained by Plane Wave Expansion (PWE) method. The size of the device is minimized from a scale of few tens of millimeters to the order of micrometers. The overall size of the filters is around 11.4 μm × 11.4 μm which is highly suitable of photonic integrated circuits

  10. Photonic crystal ring resonator based optical filters for photonic integrated circuits

    Robinson, S., E-mail: mail2robinson@gmail.com [Department of Electronics and Communication Engineering, Mount Zion College of Engineering and Technology, Pudukkottai-622507, Tamil Nadu (India)

    2014-10-15

    In this paper, a two Dimensional (2D) Photonic Crystal Ring Resonator (PCRR) based optical Filters namely Add Drop Filter, Bandpass Filter, and Bandstop Filter are designed for Photonic Integrated Circuits (PICs). The normalized output response of the filters is obtained using 2D Finite Difference Time Domain (FDTD) method and the band diagram of periodic and non-periodic structure is attained by Plane Wave Expansion (PWE) method. The size of the device is minimized from a scale of few tens of millimeters to the order of micrometers. The overall size of the filters is around 11.4 μm × 11.4 μm which is highly suitable of photonic integrated circuits.

  11. Nonlinear photonic crystals as source of entangled photons

    Full text: Nonlinear photonic crystals can be used to provide phase matching for frequency conversion in optically isotropic materials. The phase-matching mechanism proposed here is a combination of form birefringence and phase velocity dispersion in a periodic structure. Since the phase matching relies on the geometry of the photonic crystal, it becomes possible to use highly nonlinear materials. This is illustrated considering a one dimensional periodic Al0.4Ga0.6As/air structure for the generation of 1.5 micrometer light. The down-conversion process is treated quantum mechanically and analytical predictions of the down-converted emission are made. We show that emission suitable for the extraction of polarization-entangled photon pairs can be generated in one-dimensional photonic crystal structures that can be realistically fabricated. (author)

  12. Effective index approximations of photonic crystal slabs: a 2-to-1-D assessment

    Hammer, Manfred; Ivanova, Olena V.

    2009-01-01

    The optical properties of slab-like photonic crystals are often discussed on the basis of effective index (EI) approximations, where a 2-D effective refractive index profile replaces the actual 3-D structure. Our aim is to assess this approximation by analogous steps that reduce finite 2-D waveguide

  13. A novel photonic crystal fibre switch

    Alkeskjold, Thomas Tanggaard; Hermann, D.S.; Broeng, Jes;

    2003-01-01

    A new thermo-optic fibre switch is demonstrated, which utilizes the phase transitions of a thermochromic liquid crystal inside a photonic crystal fibre. We report an extinction ratio of 60 dB and an insertion loss of 1 dB.......A new thermo-optic fibre switch is demonstrated, which utilizes the phase transitions of a thermochromic liquid crystal inside a photonic crystal fibre. We report an extinction ratio of 60 dB and an insertion loss of 1 dB....

  14. Multiple slow light bands in photonic crystal coupled resonator optical waveguides constructed with a portion of photonic quasicrystals

    Coupled resonator optical waveguides (CROWs) in complex two-dimensional (2D) photonic crystals (PCs) constructed with a portion of 12-fold photonic quasicrystals (PQs) are proposed. We show that enhanced transmission and slow light can be simultaneously achieved in such waveguides as well as general CROWs. Moreover, due to higher degree of flexibility and tunability of PQs for defect mode properties compared to conventional periodic PCs, multiple slow light bands can be flexibly obtained in CROWs constructed with complex 2D PCs. Our results may lead to the development of a variety of novel ultracompact devices for photonic integrated circuits.

  15. Parametric solitons in nonlinear photonic crystals

    K Gallo; Stivala, S; Pasquazi, A.; Assanto, G

    2007-01-01

    We present theoretical and experimental investigations on the soliton dynamics associated to multiple second harmonic generation resonances in two-dimensional nonlinear photonic crystals, highlighting a wealth of new possibilities for soliton management in such structures.

  16. Recent Progress of Photonic Crystal Fibers

    Katsusuke; Tajima

    2003-01-01

    Photonic crystal fibers are attractive since we can realize a wide variety of unique features in the PCFs, which cannot be realized in conventional single-mode fibers. We describe recent progress in the PCF.

  17. Enhanced nonlinear effects in photonic crystal fibers

    LI Yan-feng; HU Ming-lie; CHAI Lu; WANG Ching-yue

    2006-01-01

    Photonic crystal fibers are a new class of single-material optical fibers with wavelength-scale air holes running down the entire fiber length.Photonic crystal fibers were first developed in 1996 and have subsequently been the focus of increasing scientific and technological interest in the field of fiber optics.The manufacturing,principles,basic properties,and some applications of photonic crystal fibers are briefly described in this paper.A review of our recent work on the nonlinear effects in photonic crystal fibers is presented,and special emphasis is placed on such effects as supercontinuum generation,frequency conversion, and solitons observed when femtosecond light pulses propagate in these fibers.

  18. Selective gas sensing for photonic crystal lasers

    Smith, Cameron; Christiansen, Mads Brøkner; Buss, Thomas; Kristensen, Anders; Lind, Johan Ulrik; Nielsen, Claus Højgård; Larsen, Niels Bent

    2011-01-01

    We facilitate photonic crystal lasers to sense gases via an additional swelling polymer film. We describe the transduction transfer function and experimentally demonstrate an enhanced ethanol vapor sensitivity over 15 dB with low humidity crosstalk....

  19. Photonic crystal biosensor in spatial fourier domain

    Hallynck, Elewout; Bienstman, Peter

    2011-01-01

    We propose a photonic crystal biosensor, operating at a single wavelength, based on analysis of resonant guided modes in the spatial Fourier domain. Sensitivities of 65 degrees per RIU and more have been simulated.

  20. Photonic crystal fiber modelling and applications

    Bjarklev, Anders Overgaard; Broeng, Jes; Libori, Stig E. Barkou;

    2001-01-01

    Photonic crystal fibers having a microstructured air-silica cross section offer new optical properties compared to conventional fibers for telecommunication, sensor, and other applications. Recent advances within research and development of these fibers are presented....

  1. Photonic crystal fibers, devices, and applications

    Wei JIN; Jian JU; Hoi Lut HO; Yeuk Lai HOO; Ailing ZHANG

    2013-01-01

    This paper reviews different types of air-silica photonic crystal fibers (PCFs), discusses their novel properties, and reports recent advances in PCF components and sensors as well as techniques for splicing PCFs to standard telecomm fibers.

  2. Wafer-scale plasmonic and photonic crystal sensors

    George, M. C.; Liu, J.-N.; Farhang, A.; Williamson, B.; Black, M.; Wangensteen, T.; Fraser, J.; Petrova, R.; Cunningham, B. T.

    2015-08-01

    200 mm diameter wafer-scale fabrication, metrology, and optical modeling results are reviewed for surface plasmon resonance (SPR) sensors based on 2-D metallic nano-dome and nano-hole arrays (NHA's) as well as 1-D photonic crystal sensors based on a leaky-waveguide mode resonance effect, with potential applications in label free sensing, surface enhanced Raman spectroscopy (SERS), and surface-enhanced fluorescence spectroscopy (SEFS). Potential markets include micro-arrays for medical diagnostics, forensic testing, environmental monitoring, and food safety. 1-D and 2-D nanostructures were fabricated on glass, fused silica, and silicon wafers using optical lithography and semiconductor processing techniques. Wafer-scale optical metrology results are compared to FDTD modeling and presented along with application-based performance results, including label-free plasmonic and photonic crystal sensing of both surface binding kinetics and bulk refractive index changes. In addition, SEFS and SERS results are presented for 1-D photonic crystal and 2-D metallic nano-array structures. Normal incidence transmittance results for a 550 nm pitch NHA showed good bulk refractive index sensitivity, however an intensity-based design with 665 nm pitch was chosen for use as a compact, label-free sensor at both 650 and 632.8 nm wavelengths. The optimized NHA sensor gives an SPR shift of about 480 nm per refractive index unit when detecting a series of 0-40% glucose solutions, but according to modeling shows about 10 times greater surface sensitivity when operating at 532 nm. Narrow-band photonic crystal resonance sensors showed quality factors over 200, with reasonable wafer-uniformity in terms of both resonance position and peak height.

  3. Photonic Crystals Mathematical Analysis and Numerical Approximation

    Dörfler, Willy; Plum, Michael; Schneider, Guido; Wieners, Christian

    2011-01-01

    This book concentrates on the mathematics of photonic crystals, which form an important class of physical structures investigated in nanotechnology. Photonic crystals are materials which are composed of two or more different dielectrics or metals, and which exhibit a spatially periodic structure, typically at the length scale of hundred nanometers. In the mathematical analysis and the numerical simulation of the partial differential equations describing nanostructures, several mathematical difficulties arise, e. g., the appropriate treatment of nonlinearities, simultaneous occurrence of contin

  4. Selective gas sensing for photonic crystal lasers

    Smith, Cameron; Christiansen, Mads Brøkner; Buss, Thomas;

    2011-01-01

    We facilitate photonic crystal lasers to sense gases via an additional swelling polymer film. We describe the transduction transfer function and experimentally demonstrate an enhanced ethanol vapor sensitivity over 15 dB with low humidity crosstalk.......We facilitate photonic crystal lasers to sense gases via an additional swelling polymer film. We describe the transduction transfer function and experimentally demonstrate an enhanced ethanol vapor sensitivity over 15 dB with low humidity crosstalk....

  5. Enhanced Gain in Photonic Crystal Amplifiers

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann;

    2012-01-01

    study of a 1 QW photonic crystal amplifier. Net gain is achieved which enables laser oscillation in photonic crystal micro cavities. The ability to freely tailor the dispersion in a semiconductor optical amplifier makes it possible to raise the optical gain considerably over a certain bandwidth. These...... results are promising for short and efficient semiconductor optical amplifiers. This effect will also benefit other devices, such as mode locked lasers....

  6. Veselago lens by photonic hyper-crystals

    Huang, Zun

    2014-01-01

    An imaging system functioning as a Veselago lens has been proposed based on the novel concept of photonic "hyper-crystal" -- an artificial optical medium synthesizing the properties of hyperbolic materials and photonic crystals. This Veselago lens shows a nearly constant negative refractive index and substantially reduced image aberrations. It can find potential applications in photolithography and hot-spots detection of silicon-based integrated circuits.

  7. Polymer and metallodielectric based photonic crystals

    Kassim, Syara

    2014-01-01

    The bottom-up colloidal synthesis of photonic crystals has attracted interest over top-down approaches due to their relatively simplicity, the potential to produce large areas, and the low-costs with this approach in fabricating complex 3-dimensional structures. This thesis focuses on the bottom-up approach in the fabrication of polymeric colloidal photonic crystals and their subsequent modification. Poly(methyl methacrylate) sub-micron spheres were used to produce opals, inverse opals and 3D...

  8. High-birefringent photonic crystal fiber

    Libori, Stig E. Barkou; Broeng, Jes; Knudsen, Erik;

    2001-01-01

    A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber.......A highly birefringent photonic crystal fiber design is analysed. Birefringence up to 10-3 is found. Random fluctuations in the cladding design are analysed, and the fiber is found to be a feasible polarization maintaining fiber....

  9. Photonic crystal fibers: fundamentals to emerging applications

    Bjarklev, Anders Overgaard

    2005-01-01

    A review of the fundamental properties of photonic crystal fibers is presented. Special focus is held on the emerging fields of application within areas such as actively controlled fiber devices and high-power fiber lasers.......A review of the fundamental properties of photonic crystal fibers is presented. Special focus is held on the emerging fields of application within areas such as actively controlled fiber devices and high-power fiber lasers....

  10. Photonic crystal waveguides in artificial opals

    Lavrinenko, Andrei; Kiyan, Roman; Neumeister, Andrei; Schweizer, Thorsten; Leyrer, Reinhold J.; Wohlleben, Wendel

    3D photonic crystals based on Si inverted-opals are numerically explored as hosts for effective air-channel waveguides, which can serve as parts of photonic circuits. Two basic shapes of straight waveguides are considered: cylindrical and a chain of spheres. Modelling shows that transmission is h...

  11. Dispersion properties of photonic crystal fibres

    Bjarklev, Anders Overgaard; Broeng, Jes; Dridi, Kim;

    1998-01-01

    Approximate dispersion and bending properties of all-silica two-dimensional photonic crystal fibres are characterised by the combination of an effective-index model and classical analysis tools for optical fibres. We believe for the first time to have predicted the dispersion properties of photonic...

  12. Propagation of Light in Photonic Crystal Fibre Devices

    Dabirian, Ali; Akbari, Mahmood; Mortensen, Niels Asger

    2005-01-01

    We describe a semi-analytical approach for three-dimensional analysis of photonic crystal fibre devices. The approach relies on modal transmission-line theory. We offer two examples illustrating the utilization of this approach in photonic crystal fibres: the verification of the coupling action in a photonic crystal fibre coupler and the modal reflectivity in a photonic crystal fibre distributed Bragg reflector.

  13. Nanostructured Porous Silicon Photonic Crystal for Applications in the Infrared

    G. Recio-Sánchez

    2012-01-01

    Full Text Available In the last decades great interest has been devoted to photonic crystals aiming at the creation of novel devices which can control light propagation. In the present work, two-dimensional (2D and three-dimensional (3D devices based on nanostructured porous silicon have been fabricated. 2D devices consist of a square mesh of 2 μm wide porous silicon veins, leaving 5×5 μm square air holes. 3D structures share the same design although multilayer porous silicon veins are used instead, providing an additional degree of modulation. These devices are fabricated from porous silicon single layers (for 2D structures or multilayers (for 3D structures, opening air holes in them by means of 1 KeV argon ion bombardment through the appropriate copper grids. For 2D structures, a complete photonic band gap for TE polarization is found in the thermal infrared range. For 3D structures, there are no complete band gaps, although several new partial gaps do exist in different high-symmetry directions. The simulation results suggest that these structures are very promising candidates for the development of low-cost photonic devices for their use in the thermal infrared range.

  14. Optical trapping apparatus, methods and applications using photonic crystal resonators

    Erickson, David; Chen, Yih-Fan

    2015-06-16

    A plurality of photonic crystal resonator optical trapping apparatuses and a plurality optical trapping methods using the plurality of photonic crystal resonator optical trapping apparatuses include located and formed over a substrate a photonic waveguide that is coupled (i.e., either separately coupled or integrally coupled) with a photonic crystal resonator. In a particular embodiment, the photonic waveguide and the photonic crystal resonator comprise a monocrystalline silicon (or other) photonic material absent any chemical functionalization. In another particular embodiment, the photonic waveguide and the photonic crystal resonator comprise a silicon nitride material which when actuating the photonic crystal resonator optical trapping apparatus with a 1064 nanometer resonant photonic radiation wavelength (or other resonant photonic radiation wavelength in a range from about 700 to about 1200 nanometers) provides no appreciable heating of an aqueous sample fluid that is analyzed by the photonic crystal resonator optical trapping apparatus.

  15. A novel photonic crystal fibre switch

    Alkeskjold, Thomas Tanggaard; Hermann, D.S.; Broeng, Jes; Bjarklev, Anders Overgaard

    2003-01-01

    A new thermo-optic fibre switch is demonstrated, which utilizes the phase transitions of a thermochromic liquid crystal inside a photonic crystal fibre. We report an extinction ratio of 60 dB and an insertion loss of 1 dB.

  16. Photonic crystal-adaptive optical devices

    Buss, Thomas

    This Ph.D. thesis presents methods for enhancing the optical functionality of transparent glass panes by introduction of invisible nanoscale surface structures, such as gratings and planar photonic cyrstals. In this way the primary functionality of the glass - transparancy - may be enhanced with...... new properties, turning window glasses or glass surfaces of hand-held electronics into multifunctional devices. Common to all examples discussed, gratings and photonic crystals are used to engineer the optical dispersion and selectively modify the direction of guided light and transfer free...... minimized, thus allowing a homogeneous, glare-free, white-light daylighting into the room. Even more functionality can be achieved when the optical effects are tunable or reconfigurable. This is investigated with photonic crystal dye lasers. These lasers combine a photonic crystal resonator with a dye...

  17. Two-Dimentional Photonic Crystal Waveguides

    Søndergaard, Thomas; Dridi, Kim

    1999-01-01

    In the recent years a new class of periodic high-index contrast dielectric structures, known as photonic bandgap structures, has been discovered. In these structures frequency intervals, known as photonic bandgaps, where propagation of electromagnetic waves is not allowed, exist due to the periodic...... dielectric function. This is analogous to semiconductors, where electronic bandgaps exist due to the periodic arrangement of atoms. As is also the case for semiconductor structures, photonic bandgap structures may become of even greater value when defects are introduced. In particular, point defects make...... possible a novel class of optical microcavities, whereas line defects make possible a novel class of waveguides. In this paper we will analyze two-dimensional photonic crystal waveguides based on photonic crystals with rods arranged on a triangular and a square lattice using a plane-wave expansion method...

  18. 2dx--user-friendly image processing for 2D crystals.

    Gipson, Bryant; Zeng, Xiangyan; Zhang, Zi Yan; Stahlberg, Henning

    2007-01-01

    Electron crystallography determines the structure of two-dimensional (2D) membrane protein crystals and other 2D crystal systems. Cryo-transmission electron microscopy records high-resolution electron micrographs, which require computer processing for three-dimensional structure reconstruction. We present a new software system 2dx, which is designed as a user-friendly, platform-independent software package for electron crystallography. 2dx assists in the management of an image-processing project, guides the user through the processing of 2D crystal images, and provides transparence for processing tasks and results. Algorithms are implemented in the form of script templates reminiscent of c-shell scripts. These templates can be easily modified or replaced by the user and can also execute modular stand-alone programs from the MRC software or from other image processing software packages. 2dx is available under the GNU General Public License at 2dx.org. PMID:17055742

  19. Two-dimensional VO2 photonic crystal selective emitter

    The design and simulation of a two-dimensional (2D) photonic crystal (PhC) selective emitter made of vanadium dioxide (VO2), a type metal oxide with a high temperature resistance, are reported. Spectral emission characteristics of the 2D VO2 PhCs were investigated using the finite difference time domain (FDTD) method. The PhC consists of a periodic array of cylindrical air microcavities. The influences of the geometric characteristic parameters are discussed. The influences of the radius and depth on the emission of the 2D VO2 PhC can be explained based on the coupled-mode theory. The emissivities at wavelengths below the cut-off wavelength were enhanced by increasing the depth. When the depth was much larger than the radius, the cut-off wavelength increased with the radius. The effect of the period on the emissivity at wavelengths less than the period was highly influenced by the diffraction modes. The designed 2D VO2 PhC emitter exhibited a selective emission that was well-matched with InGaAs cells. The spectral emissivities within the convertible wavelength range of the InGaAs cells reached 0.95, and the emissivities for non-convertible wavelengths were less than 0.3. - Highlights: • The lattice structure of metal phase VO2 does not change with temperature. • The influences of scales on the emission of a 2D VO2 PhC are discussed. • A 2D VO2 photonic crystal emitter matched well with InGaAs cell is designed. • The matched VO2 PhC emitter can highly improve the TPV system efficiency

  20. Thermal tunability of photonic bandgaps in liquid crystal filled polymer photonic crystal fiber

    Wang, Doudou; Chen, Guoxiang; Wang, Lili

    2016-05-01

    A highly tunable bandgap-guiding polymer photonic crystal fiber is designed by infiltrating the cladding air holes with liquid crystal 5CB. Structural parameter dependence and thermal tunability of the photonic bandgaps, mode properties and confinement losses of the designed fiber are investigated. Bandgaps red shift as the temperature goes up. Average thermal tuning sensitivity of 30.9 nm/°C and 20.6 nm/°C is achieved around room temperature for the first and second photonic bandgap, respectively. Our results provide theoretical references for applications of polymer photonic crystal fiber in sensing and tunable fiber-optic devices.

  1. Silicon photonic crystal resonators for label free biosensor

    Sana, Amrita Kumar; Honzawa, Keita; Amemiya, Yoshiteru; Yokoyama, Shin

    2016-04-01

    We report the fabrication and characterization of a two-dimensional (2D) silicon photonic crystal biosensor consisting of waveguides and cavity-type and defect-type resonators for enhancing the interactions between light and biomaterials. Sensitivity was measured using sucrose solution and the sensor showed the highest sensitivity [1570 nm/RIU (refractive index unit)] ever reported. We also investigated cavity size effects on resonance wavelength shift, and we observed that a large cavity exhibits a greater resonance wavelength shift. The fabricated sensor has shown a high Q of ∼105 in water and a device figure of merit of 1.2 × 105, which represent the improvements of the device performance over other photonic-crystal-based sensors.

  2. Inverse scattering of 2d photonic structures by layer-stripping

    Andresen, Marte P Hatlo; Skaar, Johannes

    2011-01-01

    Design and reconstruction of 2d and 3d photonic structures are usually carried out by forward simulations combined with optimization or intuition. Reconstruction by means of layer-stripping has been applied in seismic processing as well as in design and characterization of 1d photonic structures such as fiber Bragg gratings. Layer-stripping is based on causality, where the earliest scattered light is used to recover the structure layer-by-layer. Our set-up is a 2d layered nonmagnetic structure probed by plane polarized harmonic waves entering normal to the layers. It is assumed that the dielectric permittivity in each layer only varies orthogonal to the polarization. Based on obtained reflectance data covering a suitable frequency interval, time-localized pulse data are synthesized and applied to reconstruct the refractive index profile in the leftmost layer by identifying the local, time-domain Fresnel reflection at each point. Once the first layer is known, its impact on the reflectance data is stripped off...

  3. Coherent beam shaping using two-dimensional photonic crystals

    Gagnon, Denis; Dubé, Louis J

    2013-01-01

    Optical devices based on photonic crystals such as waveguides, lenses and beam-shapers, have received considerable theoretical and experimental attention in recent years. The production of these devices has been facilitated by the wide availability of silicon-on-insulator fabrication techniques. In this theoretical work, we show the possibility to design a coherent PhC-based beam-shaper. The basic photonic geometry used is a 2D square lattice of air holes in a high-index dielectric core. We formulate the beam shaping problem in terms of objective functions related to the amplitude and phase profile of the generated beam. We then use a parallel tabu search algorithm to minimize the two objectives simultaneously. Our results show that optimization of several attributes in integrated photonics design is well within reach of current algorithms.

  4. Design and fabrication of photonic crystals in epitaxy-free silicon for ultrathin solar cells

    Meng, Xianqin; Depauw, Valerie; Gomard, Guillaume; El Daif, Ounsi; Trompoukis, Christos; Drouard, Emmanuel; Fave, Alain; Dross, Frederic; Gordon, Ivan; Seassal, Christian

    2011-01-01

    In this paper, we present the integration of an absorbing photonic crystal within a thin film photovoltaic solar cell. Optical simulations performed on a complete solar cell revealed that patterning the epitaxial crystalline silicon active layer as a 1D and 2D photonic crystal enabled to increase its integrated absorption by 37%abs and 68%absbetween 300 nm and 1100 nm, compared to a similar but unpatterned stack. In order to fabricate such promising cells, a specific fabrication processes bas...

  5. Quantum Dots in Photonic Crystal Waveguides

    Sollner, Immo Nathanael

    This Thesis is focused on the study of quantum electrodynamics in photonic crystal waveguides. We investigate the interplay between a single quantum dot and the fundamental mode of the photonic crystal waveguide. We demonstrate experimental coupling eciencies for the spontaneous emission into the...... chiral quantum-dot-waveguide coupling. Such a structure is ideally suited for a number of applications in quantum information processing and among others we propose an on-chip spin-photon interface, a single photon transistor, and a deterministic cNOT gate.......This Thesis is focused on the study of quantum electrodynamics in photonic crystal waveguides. We investigate the interplay between a single quantum dot and the fundamental mode of the photonic crystal waveguide. We demonstrate experimental coupling eciencies for the spontaneous emission into the...... mode exceeding 98% for emitters spectrally close to the band-edge of the waveguide mode. In addition we illustrate the broadband nature of the underlying eects, by obtaining coupling eciencies above 90% for quantum dots detuned from the band edge by as far as 20nm. These values are in good agreement...

  6. A silicon photonic quasi-crystal structure obtained by interference lithography

    Lis, S.; Zakrzewski, A.; Gryglewicz, J.; Oleszkiewicz, W.; Patela, S.

    2012-06-01

    Photonic quasi-crystal structures have been prepared and investigated. Symmetrical patterns were fabricated by interference lithography in negative tone photoresist and transferred to silicon by reactive ion etching. Theoretical influences of pattern detail (radius of hole) on the photonic band gap have been studied. Three types of 2D photonic quasi-crystals have been prepared: 8-fold, 10-fold and 12-fold pattern. Finally, finite-difference time-domain method was used for theoretically prediction of transmission spectrum for fabricated 12-fold quasi-crystal.

  7. Ultrafast Optical Switching Using Photonic Molecules in Photonic Crystal Waveguides

    Zhao, Yanhui; Qiu, Kangsheng; Gao, Yunan; Xu, Xiulai

    2015-01-01

    We study the coupling between photonic molecules and waveguides in photonic crystal slab structures using finite-difference time-domain method and coupled mode theory. In a photonic molecule with two cavities, the coupling of cavity modes results in two super-modes with symmetric and anti-symmetric field distributions. When two super-modes are excited simultaneously, the energy of electric field oscillates between the two cavities. To excite and probe the energy oscillation, we integrate photonic molecule with two photonic crystal waveguides. In coupled structure, we find that the quality factors of two super-modes might be different because of different field distributions of super-modes. After optimizing the radii of air holes between two cavities of photonic molecule, nearly equal quality factors of two super-modes are achieved, and coupling strengths between the waveguide modes and two super-modes are almost the same. In this case, complete energy oscillations between two cavities can be obtained with a p...

  8. Coupled Photonic Crystal Cavity Array Laser

    Schubert, Martin

    quantum dots are carried out. In agreement with a simple gain model the structures do not show stimulated emission. The spectral splitting due to the coupling between single cavities as well as arrays of cavities is studied theoretically and experimentally. Lasing is observed for photonic crystal cavity......This thesis describes the design, fabrication and characterization of photonic crystal slab lasers. The main focus is on coupled photonic crystal cavity lasers which are examined in great detail. The cavity type which is mainly explored consists of a defect formed by a single missing hole in the...... structures with quantum wells. A detailed Analysis is conducted on single cavities, two coupled cavities and arrays of coupled cavities. The lasing threshold is determined by measuring the photoluminescence intensity depending on the excitation power. Changes in the linewidth and peak position for different...

  9. One-Dimensional Photonic Crystal Superprisms

    Ting, David

    2005-01-01

    Theoretical calculations indicate that it should be possible for one-dimensional (1D) photonic crystals (see figure) to exhibit giant dispersions known as the superprism effect. Previously, three-dimensional (3D) photonic crystal superprisms have demonstrated strong wavelength dispersion - about 500 times that of conventional prisms and diffraction gratings. Unlike diffraction gratings, superprisms do not exhibit zero-order transmission or higher-order diffraction, thereby eliminating cross-talk problems. However, the fabrication of these 3D photonic crystals requires complex electron-beam substrate patterning and multilayer thin-film sputtering processes. The proposed 1D superprism is much simpler in structural complexity and, therefore, easier to design and fabricate. Like their 3D counterparts, the 1D superprisms can exhibit giant dispersions over small spectral bands that can be tailored by judicious structure design and tuned by varying incident beam direction. Potential applications include miniature gas-sensing devices.

  10. Computational Modeling of Photonic Crystal Microcavity Single-Photon Emitters

    Saulnier, Nicole A.

    Conventional cryptography is based on algorithms that are mathematically complex and difficult to solve, such as factoring large numbers. The advent of a quantum computer would render these schemes useless. As scientists work to develop a quantum computer, cryptographers are developing new schemes for unconditionally secure cryptography. Quantum key distribution has emerged as one of the potential replacements of classical cryptography. It relics on the fact that measurement of a quantum bit changes the state of the bit and undetected eavesdropping is impossible. Single polarized photons can be used as the quantum bits, such that a quantum system would in some ways mirror the classical communication scheme. The quantum key distribution system would include components that create, transmit and detect single polarized photons. The focus of this work is on the development of an efficient single-photon source. This source is comprised of a single quantum dot inside of a photonic crystal microcavity. To better understand the physics behind the device, a computational model is developed. The model uses Finite-Difference Time-Domain methods to analyze the electromagnetic field distribution in photonic crystal microcavities. It uses an 8-band k · p perturbation theory to compute the energy band structure of the epitaxially grown quantum dots. We discuss a method that combines the results of these two calculations for determining the spontaneous emission lifetime of a quantum dot in bulk material or in a microcavity. The computational models developed in this thesis are used to identify and characterize microcavities for potential use in a single-photon source. The computational tools developed are also used to investigate novel photonic crystal microcavities that incorporate 1D distributed Bragg reflectors for vertical confinement. It is found that the spontaneous emission enhancement in the quasi-3D cavities can be significantly greater than in traditional suspended slab

  11. Analysis of thin-film photonic crystal microstructures

    Pottage, J M

    2003-01-01

    Optical-scale microstructures containing thin-film photonic crystals (TFPCs) are modelled by transfer/scattering matrix methods, based on Fourier-series expansion of the optical Bloch eigenmodes. The majority of the TFPCs considered consist of 2D arrays of holes arranged in a triangular lattice, etched into high-index Al sub x Ga sub 1 sub - sub x As and placed on a low-index oxidised substrate. These TFPCs can be easily fabricated by standard electron-beam lithography techniques. Unlike most photonic crystal devices that have been proposed, our 'intra-pass-band' TFPCs would work by exploiting the somewhat surprising properties of propagating optical Bloch waves rather than directly relying on photonic bandgaps. By numerical modelling, it is demonstrated that 2D-patterned TFPCs can support highly dispersive high-Q quasi-guided and truly-guided resonant modes, and the unusual properties of these modes are explained in terms of their Bloch-wave compositions. Modal dispersion diagrams of TFPCs, showing the loci ...

  12. Optical properties of photonic crystals

    Sakoda, Kazuaki

    2001-01-01

    The interaction between the radiation field and matter is the most fundamen­ tal source of dynamics in nature. It brings about the absorption and emission of photons, elastic and inelastic light scattering, the radiative lifetime of elec­ tronic excited states, and so on. The huge amount of energy carried from the sun by photons is the source of all activities of creatures on the earth. The absorption of photons by chlorophylls and the successive electronic excita­ tion initiate a series of chemical reactions that are known as photosynthesis, which support all life on the earth. Radiative energy is also the main source of all meteorological phenomena. The fundamentals of the radiation field and its interaction with matter were clarified by classical electromagnetism and quantum electrodynamics. These theories, we believe, explain all electromagnetic phenomena. They not only provide a firm basis for contemporary physics but also generate a vast range of technological applications. These include television, ...

  13. Integrated photonic crystal selective emitter for thermophotovoltaics

    Zhou, Zhiguang; Yehia, Omar; Bermel, Peter

    2016-01-01

    Converting blackbody thermal radiation to electricity via thermophotovoltaics (TPV) is inherently inefficient. Photon recycling using cold-side filters offers potentially improved performance but requires extremely close spacing between the thermal emitter and the receiver, namely a high view factor. Here, we propose an alternative approach for thermal energy conversion, the use of an integrated photonic crystal selective emitter (IPSE), which combines two-dimensional photonic crystal selective emitters and filters into a single device. Finite difference time domain and current transport simulations show that IPSEs can significantly suppress sub-bandgap photons. This increases heat-to-electricity conversion for photonic crystal based emitters from 35.2 up to 41.8% at 1573 K for a GaSb photovoltaic (PV) diode with matched bandgaps of 0.7 eV. The physical basis of this enhancement is a shift from a perturbative to a nonperturbative regime, which maximized photon recycling. Furthermore, combining IPSEs with nonconductive optical waveguides eliminates a key difficulty associated with TPV: the need for precise alignment between the hot selective emitter and cool PV diode. The physical effects of both the IPSE and waveguide can be quantified in terms of an extension of the concept of an effective view factor.

  14. Ultra compact spectrometer apparatus and method using photonic crystals

    Ting, David Z. (Inventor); Hill, Cory J. (Inventor); Bandara, Sumith V. (Inventor); Gunapala, Sarath D. (Inventor)

    2009-01-01

    The present invention is directed to methods of photonic crystal formation, and to methods and apparatus for using such photonic crystals, particularly in conjunction with detector arrays. Photonic crystal parameters and detector array parameters are compared to optimize the selection and orientation of a photonic crystal shape. A photonic crystal is operatively positioned relative to a plurality of light sensors. The light sensors can be separated by a pitch distance and positioned within one half of the pitch distance of an exit surface of the photonic crystals.

  15. Slow light in photonic crystal waveguides

    Moulin, G.; Jacobsen, Rune Shim; Lavrinenko, Andrei; Frandsen, Lars Hagedorn; Borel, Peter Ingo; Fage-Pedersen, Jacob

    report on the first experiments where a direct measure of the group velocity is performed; this is done by measuring the time delay of modulated light propagating through a photonic crystal waveguide. The structure is fabricated in silicon-on-insulator (SOI). A group index (c/vg) of up to almost 200 has......In photonic crystal waveguides the group velocity vg of the fundamental guided mode generally decreases at wavelengths close to the cut-off of the mode. This can be inferred from the calculated band diagram (frequency vs. wavevector) since the slope of the mode corresponds to its group velocity. We...

  16. Selective filling of Photonic Crystal Fibres

    Nielsen, Kristian; Noordegraaf, Danny; Sørensen, Thorkild; Bjarklev, Anders Overgaard; Hansen, Theis Peter

    2005-01-01

    A model for calculating the time necessary for filling one or more specific holes in a photonic crystal fibre is made. This model is verified for water, and its enabling potential is illustrated by a polymer application. Selective filling of the core in an air-guide photonic crystal fibre is...... demonstrated for a polymer and for water. Launching light into such a hybrid-material core proves to be very easily done. Finally, a scheme for enabling access to the core alone, by use of a fusion splicer, is presented....

  17. Direct mapping of light propagation in photonic crystal waveguides

    Bozhevolnyi, S.I.; Volkov, V.S.; Arentoft, J.;

    2002-01-01

    fabricated on silicon-on-insulator wafers. Based on the near-field optical images measured, we determine the bend loss to be below 2 dB in the range of 1510-1530 nm, identify the associated loss channels, and obtain an upper limit of 930 nm for the guided mode width intensity distribution at 1510 nm.......Using near-field optical microscopy, we directly map the propagation of light in the wavelength range of 1510-1560 nm along bent photonic crystal waveguides formed by removing a single row of holes in the triangular 400-nm-period lattice and connected to access ridge waveguides, the structure being...

  18. Wavelength Demultiplexer using Heterostructure Ring Resonators in Triangular Photonic Crystals

    Mohammad Reza Rakhshani

    2013-04-01

    Full Text Available In this Paper a new type of wavelength demultiplexer using ring resonators in 2D triangular photonic crystal is presented. The designed demultiplexer contents two regions which each own a resonator. Two dielectric constants are used in this demultiplexer. These structures which are called hetero have the capability to be used in wavelength division multiplexing (WDM systems. The average transferred power for the two output channels is about 93%. The crosstalk between output channels was more than -18.5dB, also the overall size of the structure was about 144µm2 which is so appropriate for fabrication and integration.

  19. Photonic crystal fiber pressure sensor

    Fávero, F. C.; Quintero, S. M. M.; Silva, V. V.; Martelli, C.; Braga, Arthur M. B.; Carvalho, Isabel C. S.; Llerena, Roberth W. A.

    2009-10-01

    A high sensitivity optical fiber pressure sensor based on a modal interferometer with high birefringence photonic fiber is proposed and demonstrated. The sensor dependence with hydrostatic pressure is evaluated both numerically and experimentally. The measured pressure sensitivity at room temperature is found to be 3.36 nmMPa-1.

  20. Extraordinary wavelength reduction in terahertz graphene-cladded photonic crystal slabs.

    Williamson, Ian A D; Mousavi, S Hossein; Wang, Zheng

    2016-01-01

    Photonic crystal slabs have been widely used in nanophotonics for light confinement, dispersion engineering, nonlinearity enhancement, and other unusual effects arising from their structural periodicity. Sub-micron device sizes and mode volumes are routine for silicon-based photonic crystal slabs, however spectrally they are limited to operate in the near infrared. Here, we show that two single-layer graphene sheets allow silicon photonic crystal slabs with submicron periodicity to operate in the terahertz regime, with an extreme 100× wavelength reduction from graphene's large kinetic inductance. The atomically thin graphene further leads to excellent out-of-plane confinement, and consequently photonic-crystal-slab band structures that closely resemble those of ideal two-dimensional photonic crystals, with broad band gaps even when the slab thickness approaches zero. The overall photonic band structure not only scales with the graphene Fermi level, but more importantly scales to lower frequencies with reduced slab thickness. Just like ideal 2D photonic crystals, graphene-cladded photonic crystal slabs confine light along line defects, forming waveguides with the propagation lengths on the order of tens of lattice constants. The proposed structure opens up the possibility to dramatically reduce the size of terahertz photonic systems by orders of magnitude. PMID:27143314

  1. Investigation on the properties of omnidirectional photonic band gaps in two-dimensional plasma photonic crystals

    The properties of omnidirectional photonic band gaps (OBGs) in two-dimensional plasma photonic crystals (2D PPCs) are theoretically investigated by the modified plane wave expansion method. In the simulation, we consider the off-plane incident wave vector. The configuration of 2D PPCs is the triangular lattices filled with the nonmagnetized plasma cylinders in the homogeneous and isotropic dielectric background. The calculated results show that the proposed 2D PPCs possess a flatbands region and the OBGs. Compared with the OBGs in the conventional 2D dielectric-air PCs, it can be obtained more easily and enlarged in the 2D PPCs with a similar structure. The effects of configurational parameters of the PPCs on the OBGs also are studied. The simulated results demonstrate that the locations of OBGs can be tuned easily by manipulating those parameters except for changing plasma collision frequency. The achieved OBGs can be enlarged by optimizations. The OBGs of two novel configurations of PPCs with different cross sections are computed for a comparison. Both configurations have the advantages of obtaining the larger OBGs compared with the conventional configuration, since the symmetry of 2D PPCs is broken by different sizes of periodically inserted plasma cylinders or connected by the embedded plasma cylinders with thin veins. The analysis of the results shows that the bandwidths of OBGs can be tuned by changing geometric and physical parameters of such two PPCs structures. The theoretical results may open a new scope for designing the omnidirectional reflectors or mirrors based on the 2D PPCs

  2. Investigation on the properties of omnidirectional photonic band gaps in two-dimensional plasma photonic crystals

    Zhang, Hai-Feng, E-mail: hanlor@163.com [Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Nanjing Artillery Academy, Nanjing 211132 (China); Liu, Shao-Bin; Li, Bing-Xiang [Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2016-01-15

    The properties of omnidirectional photonic band gaps (OBGs) in two-dimensional plasma photonic crystals (2D PPCs) are theoretically investigated by the modified plane wave expansion method. In the simulation, we consider the off-plane incident wave vector. The configuration of 2D PPCs is the triangular lattices filled with the nonmagnetized plasma cylinders in the homogeneous and isotropic dielectric background. The calculated results show that the proposed 2D PPCs possess a flatbands region and the OBGs. Compared with the OBGs in the conventional 2D dielectric-air PCs, it can be obtained more easily and enlarged in the 2D PPCs with a similar structure. The effects of configurational parameters of the PPCs on the OBGs also are studied. The simulated results demonstrate that the locations of OBGs can be tuned easily by manipulating those parameters except for changing plasma collision frequency. The achieved OBGs can be enlarged by optimizations. The OBGs of two novel configurations of PPCs with different cross sections are computed for a comparison. Both configurations have the advantages of obtaining the larger OBGs compared with the conventional configuration, since the symmetry of 2D PPCs is broken by different sizes of periodically inserted plasma cylinders or connected by the embedded plasma cylinders with thin veins. The analysis of the results shows that the bandwidths of OBGs can be tuned by changing geometric and physical parameters of such two PPCs structures. The theoretical results may open a new scope for designing the omnidirectional reflectors or mirrors based on the 2D PPCs.

  3. The 2D Selfassembly of Benzimidazole and its Co-crystallization

    Costa, Paulo; Teeter, Jacob; Kunkel, Donna; Sinitskii, Alexander; Enders, Axel

    Benzimidazoles (BI) are organic molecules that form ferroelectric crystals. Key to their ferroelectric behavior are the switchable N . . . HN type bonds and how they couple to the electron system of the molecules. We attempted to crystallize BI on various metal surfaces and studied them using STM. We observed that on Au and Ag, BI joins into zipper chains characteristic of its bulk structure that can pack into a continuous 2D layer. Because the dipole of BI lies in the direction of its switchable hydrogen bond, these zippers should in principle have reversible polarizations that point along the direction they run. BI's crystallization is reminiscent to how croconic acid (CA) crystallizes in 2D using O . . . HO bonding, suggesting that these molecules may be able to co-crystallize through OH . . . N bonds. This would present the opportunity to modify BI's properties, such as the energy needed to switch a hydrogen from a donor to acceptor site. When co-deposited, CA and BI successfully combine into a co-crystal formed by building blocks consisting of 2 CA and 2 BI molecules. These findings demonstrate the usefulness of using STM as a preliminary check to verify if two molecules are compatible with each other without having to attempt crystallization with multiple solvents and mixing methods.

  4. Adaptivity in Bandstructure Calculations of Photonic Crystals

    Krämer, Axel

    2011-01-01

    Photonic crystals are refractive materials with a certain periodic structure. By the Floquet-Bloch transformation the Maxwell eigenvalue problem for the propagating frequencies in an infinite domain (modelling an infinite crystal) is reformulated into a set of eigenvalue problems in the elementary cell, parameterised by the quasi-momemtum k. The aim of this thesis is to develop adaptive techniques to deal with the family of eigenvalue problems.

  5. Fabrication of Refractive Index Tunable Polydimethylsiloxane Photonic Crystal for Biosensor Application

    Raman, Karthik; Murthy, T. R. Srinivasa; Hegde, G. M.

    Photonic crystal based nanostructures are expected to play a significant role in next generation nanophotonic devices. Recent developments in two-dimensional (2D) photonic crystal based devices have created widespread interest as such planar photonic structures are compatible with conventional microelectronic and photonic devices. Various optical components such as waveguides, resonators, modulators and demultiplexers have been designed and fabricated based on 2D photonic crystal geometry. This paper presents the fabrication of refractive index tunable Polydimethylsiloxane (PDMS) polymer based photonic crystals. The advantages of using PDMS are mainly its chemical stability, bio-compatibility and the stack reduces sidewall roughness scattering. The PDMS structure with square lattice was fabricated by using silicon substrate patterned with SU8-2002 resist. The 600 nm period grating of PDMS is then fabricated using Nano-imprinting. In addition, the refractive index of PDMS is modified using certain additive materials. The resulting photonic crystals are suitable for application in photonic integrated circuits and biological applications such as filters, cavities or microlaser waveguides.

  6. Optically triggered Q-switched photonic crystal laser

    Maune, Brett; Witzens, Jeremy; Baehr-Jones, Thomas; Kolodrubetz, Michael; Atwater, Harry; Scherer, Axel; Hagen, Rainer; Qiu, Yueming

    2005-01-01

    An optically triggered liquid crystal infiltrated Q-switched photonic crystal laser is demonstrated. A photonic crystal laser cavity was designed and fabricated to support two orthogonally polarized high-Q cavity modes after liquid crystal infiltration. By controlling the liquid crystal orientation via a layer of photoaddressable polymer and a writing laser, the photonic crystal lasing mode can be reversibly switched between the two modes which also switches the laser’s emission polarization ...

  7. Characteristics of local photonic state density in an infinite two-dimensional photonic crystal

    Zhou Yun-Song; Wang Xue-Hua; Gu Ben-Yuan; Wang Fu-He

    2005-01-01

    The local density of photonic states (LDPS) of an infinite two-dimensional (2D) photonic crystal (PC) composed of rotated square-pillars in a 2D square lattice is calculated in terms of the plane-wave expansion method in a combination with the point group theory. The calculation results show that the LDPS strongly depends on the spatial positions.The variations of the LDPS as functions of the radial coordinate and frequency exhibit "mountain chain" structures with sharp peaks. The LDPS with large value spans a finite area and falls abruptly down to small value at the position corresponding to the interfaces between two different refractive index materials. The larger/lower LDPS occurs inward the lower/larger dielectric-constant medium. This feature can be well interpreted by the continuity of electricdisplacement vector at the interface. In the frequency range of the pseudo-PBG (photonic band gap), the LDPS keeps very low value over the whole Wiger-Seitz cell. It indicates that the spontaneous emission in 2D PCs cannot be prohibited completely, but it can be inhibited intensively when the resonate frequency falls into the pseudo-PBG.

  8. Degeneracy analysis for a super cell of a photonic crystal and its application to the creation of band gaps

    Wu, Liang; He, Sailing

    2002-01-01

    A method is introduced to analyze the degeneracy properties of the band structure of a photonic crystal making use of the super cells. The band structure associated with a super cell of a photonic crystal has degeneracies at the edge of the Brillouin zone if the photonic crystal has some kind of point group symmetry. Both E-polarization and H-polarization cases have the same degeneracies for a 2-dimensional (2D) photonic crystal. Two theorems are given and proved. These degeneracies can be li...

  9. 2D optical photon echo spectroscopy of a self-assembled quantum dot

    Fingerhut, Benjamin P.; Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California, 92697-2025 (United States); Richter, Marten [Department of Chemistry, University of California, Irvine, California, 92697-2025 (United States); Institut fuer Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623, Berlin (Germany); Luo, Jun-Wei [National Renewable Energy Laboratory, Golden, Colorado, 80401 (United States); Zunger, Alex [University of Colorado, Boulder, Colorado, 80309 (United States)

    2013-02-15

    Simulations of two dimensional coherent photon echo (2D-PE) spectra of self-assembled InAs/GaAs quantum dots (QD) in different charged states are presented revealing the coupling between the individual mono-exciton X{sup q} transitions and contributions of bi-excitons XX{sup q}. The information about the XX{sup q} states is crucial for various application scenarios of QDs, like e.g. highly efficient solar cells. The simulations rely on a microscopic description of the electronic structure by high-level atomistic many-body pseudopotential calculations. It is shown that asymmetric diagonal peak shapes and double cross-peaks are the result of XX{sup q} state contributions to the PE signal by analyzing the contributions of the individual pathways excited state emission, ground state bleach and excited state absorption. The results show that from the detuned X{sup q} and XX{sup q} contributions the bi-exciton binding energies of the XX{sup q} manifold are revealed in 2D-PE signals. (copyright 2012 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Photon statistics in scintillation crystals

    Bora, Vaibhav Joga Singh

    Scintillation based gamma-ray detectors are widely used in medical imaging, high-energy physics, astronomy and national security. Scintillation gamma-ray detectors are eld-tested, relatively inexpensive, and have good detection eciency. Semi-conductor detectors are gaining popularity because of their superior capability to resolve gamma-ray energies. However, they are relatively hard to manufacture and therefore, at this time, not available in as large formats and much more expensive than scintillation gamma-ray detectors. Scintillation gamma-ray detectors consist of: a scintillator, a material that emits optical (scintillation) photons when it interacts with ionization radiation, and an optical detector that detects the emitted scintillation photons and converts them into an electrical signal. Compared to semiconductor gamma-ray detectors, scintillation gamma-ray detectors have relatively poor capability to resolve gamma-ray energies. This is in large part attributed to the "statistical limit" on the number of scintillation photons. The origin of this statistical limit is the assumption that scintillation photons are either Poisson distributed or super-Poisson distributed. This statistical limit is often dened by the Fano factor. The Fano factor of an integer-valued random process is dened as the ratio of its variance to its mean. Therefore, a Poisson process has a Fano factor of one. The classical theory of light limits the Fano factor of the number of photons to a value greater than or equal to one (Poisson case). However, the quantum theory of light allows for Fano factors to be less than one. We used two methods to look at the correlations between two detectors looking at same scintillation pulse to estimate the Fano factor of the scintillation photons. The relationship between the Fano factor and the correlation between the integral of the two signals detected was analytically derived, and the Fano factor was estimated using the measurements for SrI2:Eu, YAP

  11. Self-assembled tunable photonic hyper-crystals

    Smolyaninova, Vera N; Lahneman, David; Narimanov, Evgenii E; Smolyaninov, Igor I

    2013-01-01

    We demonstrate a novel artificial optical material, a photonic hyper-crystal, which combines the most interesting features of hyperbolic metamaterials and photonic crystals. Similar to hyperbolic metamaterials, photonic hyper-crystals exhibit broadband divergence in their photonic density of states due to the lack of usual diffraction limit on the photon wave vector. On the other hand, similar to photonic crystals, hyperbolic dispersion law of extraordinary photons is modulated by forbidden gaps near the boundaries of photonic Brillouin zones. Three dimensional self-assembly of photonic hyper-crystals has been achieved by application of external magnetic field to a cobalt nanoparticle-based ferrofluid. Unique spectral properties of photonic hyper-crystals lead to extreme sensitivity of the material to monolayer coatings of cobalt nanoparticles, which should find numerous applications in biological and chemical sensing.

  12. Polarization squeezing with photonic crystal fibers

    Milanovic, J.; Huck, Alexander; Heersink, J.; Marquardt, C.; Andersen, Ulrik Lund; Leuchs, G.

    2007-01-01

    We report on the generation of polarization squeezing by employing intense, ultrashort light pulses in a single pass method in photonic crystal fibers. We investigated the squeezing behavior near the zero-dispersion wavelength and in the anomalous dispersion regime by using two distinct fibers. We...

  13. Topology optimised planar photonic crystal building blocks

    Frandsen, Lars Hagedorn; Hede, K. K.; Borel, Peter Ingo; Jensen, Jakob Søndergaard; Sigmund, Ole

    A photonic crystal waveguide (PhCW) 1x4 splitter has been constructed from PhCW 60° bends1 and Y-splitters2 that have been designed individually by utilising topology optimisation3. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1) and exhibits a broadband splitting for...

  14. Silicon photonic crystals and spontaneous emission

    Dood, Michiel Jacob Andries de

    2002-01-01

    Photonic crystals, i.e. materials that have a periodic variation in refractive index, form an interesting new class of materials that can be used to modify spontaneous emission and manipulate optical modes in ways that were impossible so far. This thesis is divided in three parts. Part I discusses

  15. Monolithic photonic crystal quantum-cascade laser

    Benz, A; Deutsch, C H; Fasching, G; Unterrainer, K [Photonics Institute and Center for Micro- and Nanostructures, Vienna University of Technology, Gusshausstrasse 29/387, A-1040 Vienna (Austria); Andrews, A M; Klang, P; Schrenk, W; Strasser, G, E-mail: alexander.benz@tuwien.ac.a [Institute of Solid-State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, Floragasse 7/362, A-1040 Vienna (Austria)

    2009-11-15

    We present the design and realization of active photonic crystal (PhC) terahertz quantum-cascade lasers. The devices consist of sub-wavelength isolated pillars which are embedded in a double-metal waveguide. The lasing is observed at flat-band regions not in the bandgap itself. A stable single-mode emission under all driving conditions is achieved.

  16. Fabrication and Analysis of Photonic Crystals

    Campbell, Dean J.; Korte, Kylee E.; Xia, Younan

    2007-01-01

    These laboratory experiments are designed to explore aspects of nanoscale chemistry by constructing and spectroscopically analyzing thin films of photonic crystals. Films comprised of colloidal spheres and polydimethylsiloxane exhibit diffraction-based stop bands that shift reversibly upon exposure to some common solvents. Topics covered in these…

  17. Bandwidth engineering of photonic crystal waveguide bends

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Harpøth, Anders;

    2004-01-01

    An effective design principle has been applied to photonic crystal waveguide bends fabricated in silicon-on-insulator material using deep UV lithography resulting in a large increase in the low-loss bandwidth of the bends. Furthermore, it is experimentally demonstrated that the absolute bandwidth...

  18. low pump power photonic crystal fibre amplifiers

    Hougaard, Kristian G.; Broeng, Jes; Bjarklev, Anders Overgaard

    2003-01-01

    Designs of low pump power optical amplifiers, based on photonic crystal fibres are presented. The potential of these fibre amplifiers is investigated, and it is demonstrated that such amplifiers may deliver gains of more than 15 dB at 1550 nm with less than 1 mW of optical pump power....

  19. Photonic crystal nanostructures for optical biosensing applications

    Dorfner, D.; Zabel, T.; Hürlimann, T.;

    2009-01-01

    We present the design, fabrication and optical investigation of photonic crystal (PhC) nanocavity drop filters for use as optical biosensors. The resonant cavity mode wavelength and Q-factor are studied as a function of the ambient refractive index and as a function of adsorbed proteins (bovine...

  20. Chaotic behaviour of photonic crystals resonators

    Di Falco, A.

    2015-02-08

    We show here theoretically and experimentally how chaotic Photonic Crystal resonators can be used for en- ergy harvesting applications and the demonstration of fundamental theories, like the onset of superradiance in quantum systems. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  1. Limits of slow light in photonic crystals

    Pedersen, Jesper Goor; Xiao, Sanshui; Mortensen, N. Asger

    2008-01-01

    are presented. The results obtained are entirely general and may be applied to any effect which results in a broadening of the electromagnetic states, such as loss, disorder, and finite-size effects. This significantly limits the reduction in group velocity attainable via photonic crystals....

  2. Planar photonic crystal waveguides in silicon oxynitride

    Liu, Haoling; Frandsen, Lars Hagedorn; Borel, Peter Ingo;

    visible wavelengths they absorb light very strongly. In contrary, silicon oxynitride (SiON) glasses offer high transparency down to blue and ultraviolet wavelengths. Thus, SiON photonic crystal waveguides can open for new possibilities, e.g., within sensing and life sciences. We have fabricated Si...

  3. All-polymer photonic crystal slab sensor

    Hermannsson, Pétur Gordon; Sørensen, Kristian Tølbøl; Vannahme, Christoph;

    2015-01-01

    An all-polymer photonic crystal slab sensor is presented, and shown to exhibit narrow resonant reflection with a FWHM of less than 1 nm and a sensitivity of 31 nm/RIU when sensing media with refractive indices around that of water. This results in a detection limit of 4.5x10-6 RIU when measured...

  4. Photonic Crystal Sensors Based on Porous Silicon

    Claudia Pacholski

    2013-04-01

    Full Text Available Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential.

  5. Finite element analysis of photonic crystal fibers

    Uranus, H.P.; Hoekstra, H.J.W.M.; Groesen, van E.

    2005-01-01

    A finite-element-based vectorial optical mode solver, furnished with Bayliss-Gunzburger-Turkel-like transparent boundary conditions, is used to rigorously analyze photonic crystal fibers (PCFs). Both the real and imaginary part of the modal indices can be computed in a relatively small computational

  6. Photonic crystal fibres - novel fibres, new applications

    Bjarklev, Anders Overgaard; Riishede, Jesper; Libori, Stig E. Barkou; Broeng, Jes

    Photonic crystal fibres with an air-silica micro-structured cross-section, offer novel fibre designs and new fibre characteristics, compared to standard silica fibres, such as new guiding mechanisms, different group velocity dispersion characteristics and new possibilities when designed as non...

  7. Vectorial analysis of dielectric photonic crystal VCSEL

    Chung, Il-Sug; Mørk, Jesper

    A new vertical-cavity surface-emitting laser structure employing a dielectric photonic crystal mirror has been suggested and been numerically investigated. The new structure has a smaller threshold gain, a moderate strength of single-transverse-mode operation, a high quality of emission beam free...

  8. Quantum Electrodynamics in Photonic Crystal Waveguides

    Nielsen, Henri Thyrrestrup

    In this thesis we have performed quantum electrodynamics (QED) experiments in photonic crystal (PhC) waveguides and cavity QED in the Anderson localized regime in disordered PhC waveguides. Decay rate measurements of quantum dots embedded in PhC waveguides has been used to map out the variations in...

  9. Strong transmittance above the light line in mid-infrared two-dimensional photonic crystals

    Kraeh, Christian, E-mail: christian.kraeh@tum.de [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, D-81739 München (Germany); Walter Schottky Institut, Technische Universität München, Am Coulombwall 4, D-85748 Garching (Germany); Martinez-Hurtado, J. L.; Zeitlmair, Martin; Finley, Jonathan J. [Walter Schottky Institut, Technische Universität München, Am Coulombwall 4, D-85748 Garching (Germany); Popescu, Alexandru; Hedler, Harry [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, D-81739 München (Germany)

    2015-06-14

    The mid-infrared region of the electromagnetic spectrum between 3 and 8 μm hosts absorption lines of gases relevant for chemical and biological sensing. 2D photonic crystal structures capable of guiding light in this region of the spectrum have been widely studied, and their implementation into miniaturized sensors has been proposed. However, light guiding in conventional 2D photonic crystals is usually restricted to a frequency range below the light line, which is the dispersion relation of light in the media surrounding the structures. These structures rely on total internal reflection for confinement of the light in z-direction normal to the lattice plane. In this work, 2D mid-infrared photonic crystals consisting of microtube arrays that mitigate these limitations have been developed. Due to their high aspect ratios of ∼1:30, they are perceived as semi-infinite in the z-direction. Light transmission experiments in the 5–8 μm range reveal attenuations as low as 0.27 dB/100 μm, surpassing the limitations for light guiding above the light line in conventional 2D photonic crystals. Fair agreement is obtained between these experiments, 2D band structure and transmission simulations.

  10. Strong transmittance above the light line in mid-infrared two-dimensional photonic crystals

    The mid-infrared region of the electromagnetic spectrum between 3 and 8 μm hosts absorption lines of gases relevant for chemical and biological sensing. 2D photonic crystal structures capable of guiding light in this region of the spectrum have been widely studied, and their implementation into miniaturized sensors has been proposed. However, light guiding in conventional 2D photonic crystals is usually restricted to a frequency range below the light line, which is the dispersion relation of light in the media surrounding the structures. These structures rely on total internal reflection for confinement of the light in z-direction normal to the lattice plane. In this work, 2D mid-infrared photonic crystals consisting of microtube arrays that mitigate these limitations have been developed. Due to their high aspect ratios of ∼1:30, they are perceived as semi-infinite in the z-direction. Light transmission experiments in the 5–8 μm range reveal attenuations as low as 0.27 dB/100 μm, surpassing the limitations for light guiding above the light line in conventional 2D photonic crystals. Fair agreement is obtained between these experiments, 2D band structure and transmission simulations

  11. Membrane proteins: functional and structural studies using reconstituted proteoliposomes and 2-D crystals

    Rigaud J.-L.

    2002-01-01

    Full Text Available Reconstitution of membrane proteins into lipid bilayers is a powerful tool to analyze functional as well as structural areas of membrane protein research. First, the proper incorporation of a purified membrane protein into closed lipid vesicles, to produce proteoliposomes, allows the investigation of transport and/or catalytic properties of any membrane protein without interference by other membrane components. Second, the incorporation of a large amount of membrane proteins into lipid bilayers to grow crystals confined to two dimensions has recently opened a new way to solve their structure at high resolution using electron crystallography. However, reconstitution of membrane proteins into functional proteoliposomes or 2-D crystallization has been an empirical domain, which has been viewed for a long time more like "black magic" than science. Nevertheless, in the last ten years, important progress has been made in acquiring knowledge of lipid-protein-detergent interactions and has permitted to build upon a set of basic principles that has limited the empirical approach of reconstitution experiments. Reconstitution strategies have been improved and new strategies have been developed, facilitating the success rate of proteoliposome formation and 2-D crystallization. This review deals with the various strategies available to obtain proteoliposomes and 2-D crystals from detergent-solubilized proteins. It gives an overview of the methods that have been applied, which may be of help for reconstituting more proteins into lipid bilayers in a form suitable for functional studies at the molecular level and for high-resolution structural analysis.

  12. The Gain Properties of 1-D Active Photonic Crystal

    2003-01-01

    The terminology 'ID frequency'(w ID) is proposed after analyzing the 1D active photonic crystal based on the transfer matrix method. The relationship between wID and the structure parameters of the photonic crystal is investigated.

  13. Modeling of Photonic Band Gap Crystals and Applications

    Ihab Fathy El-Kady

    2002-08-27

    In this work, the authors have undertaken a theoretical approach to the complex problem of modeling the flow of electromagnetic waves in photonic crystals. The focus is to address the feasibility of using the exciting phenomena of photonic gaps (PBG) in actual applications. The authors start by providing analytical derivations of the computational electromagnetic methods used in their work. They also present a detailed explanation of the physics underlying each approach, as well as a comparative study of the strengths and weaknesses of each method. The Plane Wave expansion, Transfer Matrix, and Finite Difference time Domain Methods are addressed. They also introduce a new theoretical approach, the Modal Expansion Method. They then shift the attention to actual applications. They begin with a discussion of 2D photonic crystal wave guides. The structure addressed consists of a 2D hexagonal structure of air cylinders in a layered dielectric background. Comparison with the performance of a conventional guide is made, as well as suggestions for enhancing it. The studies provide an upper theoretical limit on the performance of such guides, as they assumed no crystal imperfections and non-absorbing media. Next, they study 3D metallic PBG materials at near infrared and optical wavelengths. The main objective is to study the importance of absorption in the metal and the suitability of observing photonic band gaps in such structures. They study simple cubic structures where the metallic scatters are either cubes or interconnected metallic rods. Several metals are studied (aluminum, gold, copper, and silver). The effect of topology is addressed and isolated metallic cubes are found to be less lossy than the connected rod structures. The results reveal that the best performance is obtained by choosing metals with a large negative real part of the dielectric function, together with a relatively small imaginary part. Finally, they point out a new direction in photonic crystal

  14. Controlling Anderson localization in disordered photonic crystal waveguides

    Smolka, Stephan; Garcia, Pedro D.; Lodahl, Peter

    2010-01-01

    We prove Anderson localization in the slow-light regime of a photonic crystal waveguide by measuring the ensemble-averaged localization length which is controlled by the dispersion of the disordered photonic crystal waveguide.......We prove Anderson localization in the slow-light regime of a photonic crystal waveguide by measuring the ensemble-averaged localization length which is controlled by the dispersion of the disordered photonic crystal waveguide....

  15. Photonics and lasing in liquid crystals

    Alison D. Ford

    2006-07-01

    Full Text Available Lasers were invented some 40 years ago and are now used in a plethora of applications. Stable liquid crystals were discovered at about the same time, and are now the basis of a large display industry. Both technologies involve photonics, the former in the creation and use of light and the latter in the control and manipulation of light. However, it is only recently that these two mature technologies have been combined to form liquid-crystal lasers, heralding a new era for these photonic materials and the potential for novel applications. We summarize the characteristics of liquid crystals that lead to laser devices, the wide diversity of possible laser systems, and the properties of the light produced.

  16. Dual curved photonic crystal ring resonator based channel drop filter using two-dimensional photonic crystal structure

    Chhipa, Mayur Kumar; Dusad, Lalit Kumar

    2016-05-01

    In this paper channel drop filter (CDF) is designed using dual curved photonic crystal ring resonator (PCRR). The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method and the photonic crystal (PhC) based on two dimensional (2D) square lattice periodic arrays of silicon (Si) rods in air structure have been investigated using finite difference time domain (FDTD) method. The number of rods in Z and X directions is 21 and 20 respectively with lattice constant 0.540 nm and rod radius r = 0.1 µm. The channel drop filter has been optimized for telecommunication wavelengths λ = 1.591 µm with refractive indices 3.533. In the designed structure further analysis is also done by changing whole rods refractive index and it has been observed that this filter may be used for filtering several other channels also. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm2.

  17. Maximizing Photoluminescence Extraction in Silicon Photonic Crystal Slabs

    Mahdavi, Ali; Sarau, George; Xavier, Jolly; Paraïso, Taofiq K.; Christiansen, Silke; Vollmer, Frank

    2016-01-01

    Photonic crystal modes can be tailored for increasing light matter interactions and light extraction efficiencies. These PhC properties have been explored for improving the device performance of LEDs, solar cells and precision biosensors. Tuning the extended band structure of 2D PhC provides a means for increasing light extraction throughout a planar device. This requires careful design and fabrication of PhC with a desirable mode structure overlapping with the spectral region of emission. We show a method for predicting and maximizing light extraction from 2D photonic crystal slabs, exemplified by maximizing silicon photoluminescence (PL). Systematically varying the lattice constant and filling factor, we predict the increases in PL intensity from band structure calculations and confirm predictions in micro-PL experiments. With the near optimal design parameters of PhC, we demonstrate more than 500-fold increase in PL intensity, measured near band edge of silicon at room temperature, an enhancement by an order of magnitude more than what has been reported. PMID:27113674

  18. Maximizing Photoluminescence Extraction in Silicon Photonic Crystal Slabs.

    Mahdavi, Ali; Sarau, George; Xavier, Jolly; Paraïso, Taofiq K; Christiansen, Silke; Vollmer, Frank

    2016-01-01

    Photonic crystal modes can be tailored for increasing light matter interactions and light extraction efficiencies. These PhC properties have been explored for improving the device performance of LEDs, solar cells and precision biosensors. Tuning the extended band structure of 2D PhC provides a means for increasing light extraction throughout a planar device. This requires careful design and fabrication of PhC with a desirable mode structure overlapping with the spectral region of emission. We show a method for predicting and maximizing light extraction from 2D photonic crystal slabs, exemplified by maximizing silicon photoluminescence (PL). Systematically varying the lattice constant and filling factor, we predict the increases in PL intensity from band structure calculations and confirm predictions in micro-PL experiments. With the near optimal design parameters of PhC, we demonstrate more than 500-fold increase in PL intensity, measured near band edge of silicon at room temperature, an enhancement by an order of magnitude more than what has been reported. PMID:27113674

  19. 2D Crystal heterostructures properties and growth by molecular beam epitaxy

    Xing, Grace Huili

    Two-dimensional (2D) crystals such as transition metal dichalcogenides (TMDs) along with other families of layered materials including graphene, SnSe2, GaSe, BN etc, has attracted intense attention from the scientific community. One monolayer of such materials represent the thinnest ``quantum wells''. These layered materials typically possess an in-plane hexagonal crystal structure, and can be stacked together by interlayer van der Waals interactions. Therefore, it is possible to create novel heterostructures by stacking materials with large lattice mismatches and different properties, for instance, superconductors (NbSe2) , metals, semi-metals (graphene), semiconductors (MoS2) and insulators (BN). Numerous novel material properties and device concepts have been discovered, proposed and demonstrated lately. However, the low internal photoluminescence efficiency (IPE, <1%) and low carrier mobility observed in the 2D semiconductors suggest strongly that the materials under investigation today most likely suffer from a high concentration of defects. In this talk, I will share our progress and the challenges we face in terms of preparing, characterizing these 2D crystals as well as pursuing their applications. This work has been supported in part by NSF, AFOSR and LEAST, one of the STARnet centers.

  20. ScintSim1: A new Monte Carlo simulation code for transport of optical photons in 2D arrays of scintillation detectors.

    Mosleh-Shirazi, Mohammad Amin; Zarrini-Monfared, Zinat; Karbasi, Sareh; Zamani, Ali

    2014-01-01

    Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all optimization. PMID:24600168

  1. Electrically tunable liquid crystal photonic bandgap fiber laser

    Olausson, Christina Bjarnal Thulin; Scolari, Lara; Wei, Lei;

    2010-01-01

    We demonstrate electrical tunability of a fiber laser by using a liquid crystal photonic bandgap fiber. Tuning of the laser is achieved by combining the wavelength filtering effect of a liquid crystal photonic bandgap fiber device with an ytterbium-doped photonic crystal fiber. We fabricate an all......-spliced laser cavity based on a liquid crystal photonic bandgap fiber mounted on a silicon assembly, a pump/signal combiner with single-mode signal feed-through and an ytterbium-doped photonic crystal fiber. The laser cavity produces a single-mode output and is tuned in the range 1040-1065nm by applying...

  2. Output couplers for 3D photonic crystal waveguides

    Full text: One crucial practical problem facing 3D photonic crystal applications is finding a way to couple electromagnetic energy efficiently into and out of a 3D photonic crystal waveguide. We investigate two approaches for solving this problem: the photonic crystal horn antenna; and the conventional waveguide to 3D photonic crystal waveguide mode coupler. We demonstrate both approaches theoretically using numerical simulations, and experimentally using prototypes operating at microwave frequencies. Both methods succeed in providing highly efficient coupling into and out of the 3D photonic crystal waveguide over a wide bandwidth, thereby demonstrating two solutions to the output coupling problem. Copyright (2005) Australian Institute of Physics

  3. Photonic density of states maps for design of photonic crystal devices

    Sukhoivanov, I. A.; Guryev, I. V.; Lucio, J. A. Andrade; Mendez, E. Alvarado; Trejo-Duran, M.; Torres-Cisneros, M.

    2010-01-01

    In this work, it has been investigated whether photonic density of states maps can be applied to the design of photonic crystal-based devices. For this reason, comparison between photonic density of states maps and transmittance maps was carried out. Results of comparison show full correspondence between these characteristics. Photonic density of states maps appear to be preferable for the design of photonic crystal devices, than photonic band gap maps presented earlier and than transmittance...

  4. Photonic crystal fibres - a variety of applications

    Bjarklev, Anders Overgaard; Riishede, Jesper

    2002-01-01

    bandgap fibers. These fibers have today reached a level of maturity where they may be used as building blocks for a variety of new applications. Today's research is focusing increasingly on applications of the fibres, thus redirecting earlier focus on crystal fibers themselves and their unique guiding...... mechanisms. Some of the new applications that are receiving a significant amount of attention are based on nonlinear effects-super continuum generation and applications of such being highly studied examples. In this presentation, we will discuss the basic properties of photonic crystal fibers and highlight...

  5. A plasma photonic crystal bandgap device

    Wang, B.; Cappelli, M. A.

    2016-04-01

    A fully tunable plasma photonic crystal is used to control the propagation of free space electromagnetic waves in the S to X bands of the microwave spectrum. An array of discharge plasma tubes forms a simple square crystal structure with the individual plasma dielectric constant tuned through variation in the plasma density. We show, through simulations and experiments, that transverse electric mode bandgaps exist, arising from the positive and negative dielectric constant regimes of the plasma, and that the respective bandgap frequencies can be shifted through changing the dielectric constant by varying discharge current density.

  6. Topology optimized mode conversion in a photonic crystal waveguide fabricated in siliconon-insulator material

    Frandsen, Lars Hagedorn; Elesin, Yuriy; Frellsen, Louise Floor;

    2014-01-01

    We have designed and for the first time experimentally verified a topology optimized mode converter with a footprint of ∼6.3 μm × ∼3.6 μm which converts the fundamental even mode to the higher order odd mode of a dispersion engineered photonic crystal waveguide. 2D and 3D topology optimization is...

  7. Energy flow in photonic crystal waveguides

    Søndergaard, Thomas; Dridi, Kim

    2000-01-01

    Theoretical and numerical investigations of energy flow in photonic crystal waveguides made of line defects and branching points are presented. It is shown that vortices of energy flow may occur, and the net energy flow along: the line defect is described via the effective propagation velocity....... Single-mode and multimode operations are studied, and dispersion relations are computed for different waveguide widths. Both strong positive, strong negative, and zero dispersion an possible. It is shown that geometric parameters such as the nature of the lattice, the line defect orientation, the defect...... width, and the branching-point geometry have a significant influence on the electrodynamics. These are important issues for the fabrication of photonic crystal structures....

  8. A tunable microwave plasma photonic crystal filter

    Wang, B.; Cappelli, M. A. [Stanford Plasma Physics Laboratory, Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States)

    2015-10-26

    The integration of gaseous plasma elements into a microwave photonic crystal band gap cavity structure allows for active tuning of the device. An alumina rod array microwave photonic crystal waveguide resonator is simulated and characterized through finite difference time domain methods. A gaseous plasma element is integrated into the cavity structure and the effect of plasma density on the transmission properties of the structure is investigated. We show, through both simulations and experiments, that the permittivity of the plasma can be adjusted to shift the peak resonance to allow for both switching and tunability of transmission. The experimentally measured peak shifts in transmission are compared to those simulated and the electron density of the gaseous plasma element is calculated and compared to values determined from the measured discharge current density.

  9. A tunable microwave plasma photonic crystal filter

    Wang, B.; Cappelli, M. A.

    2015-10-01

    The integration of gaseous plasma elements into a microwave photonic crystal band gap cavity structure allows for active tuning of the device. An alumina rod array microwave photonic crystal waveguide resonator is simulated and characterized through finite difference time domain methods. A gaseous plasma element is integrated into the cavity structure and the effect of plasma density on the transmission properties of the structure is investigated. We show, through both simulations and experiments, that the permittivity of the plasma can be adjusted to shift the peak resonance to allow for both switching and tunability of transmission. The experimentally measured peak shifts in transmission are compared to those simulated and the electron density of the gaseous plasma element is calculated and compared to values determined from the measured discharge current density.

  10. "Wandering" soliton in a nonlinear photonic crystal

    Lysak, T. M.; Trofimov, V. A.

    2015-12-01

    On the basis of computer simulation, we demonstrate the possibility of a new type of "wandering" solitons implementation in nonlinear periodic layered structures. "Wandering" soliton moves across the layers, repeatedly changing its direction of motion due to the reflection from the photonic crystal (PC) boundaries with the ambient medium. The initial soliton is located inside a PC and occupies several of its layers. Its profile can be found as the solution of the corresponding nonlinear eigenvalue problem. "Wandering" solitons are formed as a result of a large perturbation of the wave vector, which leads to the soliton motion across photonic crystal layers. In the process of reflection from the boundary with the ambient medium, the soliton partly penetrates into the ambient medium at a depth equal to the width of several PC layers. A slow return of light energy, which previously left the PC, can take place at this moment.