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Sample records for 1d photonic crystals

  1. A 1-D dusty plasma photonic crystal

    SciTech Connect

    Mitu, M. L.; Ticoş, C. M.; Toader, D.; Banu, N.; Scurtu, A.

    2013-09-21

    It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 μm to about 1350 μm, depending on the rf power fed into the discharge.

  2. Extended-Range Ultrarefractive 1D Photonic Crystal Prisms

    NASA Technical Reports Server (NTRS)

    Ting, David Z.

    2007-01-01

    A proposal has been made to exploit the special wavelength-dispersive characteristics of devices of the type described in One-Dimensional Photonic Crystal Superprisms (NPO-30232) NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 10a. A photonic crystal is an optical component that has a periodic structure comprising two dielectric materials with high dielectric contrast (e.g., a semiconductor and air), with geometrical feature sizes comparable to or smaller than light wavelengths of interest. Experimental superprisms have been realized as photonic crystals having three-dimensional (3D) structures comprising regions of amorphous Si alternating with regions of SiO2, fabricated in a complex process that included sputtering. A photonic crystal of the type to be exploited according to the present proposal is said to be one-dimensional (1D) because its contrasting dielectric materials would be stacked in parallel planar layers; in other words, there would be spatial periodicity in one dimension only. The processes of designing and fabricating 1D photonic crystal superprisms would be simpler and, hence, would cost less than do those for 3D photonic crystal superprisms. As in 3D structures, 1D photonic crystals may be used in applications such as wavelength-division multiplexing. In the extended-range configuration, it is also suitable for spectrometry applications. As an engineered structure or artificially engineered material, a photonic crystal can exhibit optical properties not commonly found in natural substances. Prior research had revealed several classes of photonic crystal structures for which the propagation of electromagnetic radiation is forbidden in certain frequency ranges, denoted photonic bandgaps. It had also been found that in narrow frequency bands just outside the photonic bandgaps, the angular wavelength dispersion of electromagnetic waves propagating in photonic crystal superprisms is much stronger than is the angular wavelength dispersion obtained

  3. Engineered atom-light interactions in 1D photonic crystals

    NASA Astrophysics Data System (ADS)

    Martin, Michael J.; Hung, Chen-Lung; Yu, Su-Peng; Goban, Akihisa; Muniz, Juan A.; Hood, Jonathan D.; Norte, Richard; McClung, Andrew C.; Meenehan, Sean M.; Cohen, Justin D.; Lee, Jae Hoon; Peng, Lucas; Painter, Oskar; Kimble, H. Jeff

    2014-05-01

    Nano- and microscale optical systems offer efficient and scalable quantum interfaces through enhanced atom-field coupling in both resonators and continuous waveguides. Beyond these conventional topologies, new opportunities emerge from the integration of ultracold atomic systems with nanoscale photonic crystals. One-dimensional photonic crystal waveguides can be engineered for both stable trapping configurations and strong atom-photon interactions, enabling novel cavity QED and quantum many-body systems, as well as distributed quantum networks. We present the experimental realization of such a nanophotonic quantum interface based on a nanoscale photonic crystal waveguide, demonstrating a fractional waveguide coupling of Γ1 D /Γ' of 0 . 32 +/- 0 . 08 , where Γ1 D (Γ') is the atomic emission rate into the guided (all other) mode(s). We also discuss progress towards intra-waveguide trapping of ultracold Cs. This work was supported by the IQIM, an NSF Physics Frontiers Center with support from the Moore Foundation, the DARPA ORCHID program, the AFOSR QuMPASS MURI, the DoD NSSEFF program, NSF, and the Kavli Nanoscience Institute (KNI) at Caltech.

  4. Coherent thermal conductance of 1-D photonic crystals

    NASA Astrophysics Data System (ADS)

    Tschikin, Maria; Ben-Abdallah, Philippe; Biehs, Svend-Age

    2012-10-01

    We present an exact calculation of coherent thermal conductance in 1-D multilayer photonic crystals using the S-matrix method. In particular, we study the thermal conductance in a bilayer structure of Si/vacuum or Al2O3/vacuum slabs by means of the exact radiative heat flux expression. Based on the results obtained for the Al2O3/vacuum structure we show by comparison with previous works that the material losses and (localized) surface modes supported by the inner layers play a fundamental role and cannot be omitted in the definition of thermal conductance. Our results could have significant implications in the conception of efficient thermal barriers.

  5. Optical properties of LEDs with patterned 1D photonic crystal

    NASA Astrophysics Data System (ADS)

    Hronec, P.; Kuzma, A.; Å kriniarová, J.; Kováč, J.; Benčurová, A.; Haščík, Å.; Nemec, P.

    2015-08-01

    In this paper we focus on the application of the one-dimensional photonic crystal (1D PhC) structures on the top of Al0.295Ga0.705As/GaAs multi-quantum well light emitting diode (MQW LED). 1D PhC structures with periods of 600 nm, 700 nm, 800 nm, and 900 nm were fabricated by the E-Beam Direct Write (EBDW) Lithography. Effect of 1D PhC period on the light extraction enhancement was studied. 1D PhC LED radiation profiles were obtained from Near Surface Light Emission Images (NSLEI). Measurements showed the strongest light extraction enhancement using 800 nm period of PhC. Investigation of PhC LED radiation profiles showed strong light decoupling when light reaches PhC structure. Achieved LEE was from 22.6% for 600 nm PhC LED to 47.0% for 800 nm PhC LED. LED with PhC structure at its surface was simulated by FDTD simulation method under excitation of appropriate launch field.

  6. Parametric Simulations of Slanted 1D Photonic Crystal Sensors

    NASA Astrophysics Data System (ADS)

    Breuer-Weil, Aaron; Almasoud, Naif Nasser; Abbasi, Badaruddin; Yetisen, Ali K.; Yun, Seok-Hyun; Butt, Haider

    2016-03-01

    Photonic crystals and band gap materials act as manipulators of light and have a plethora of applications. They are made up of stacks of alternating dielectric constants. This article shows the simulations of an inclined, one dimensional and tuneble photonic crystal, using numerical finite element methods. The photonic crystal was made up of silver nanoparticles embedded in a hydrogel matrix and it has the ability to change and recover its periodicity. A series of factors concerning the geometry of the lattice were tested in order to analyze the efficiency, performance and optimize the properties of the optical sensor. These factors range from the size of the nanoparticles and their density within the stacks, to observing the effect of diffraction angle in readouts.

  7. Parametric Simulations of Slanted 1D Photonic Crystal Sensors.

    PubMed

    Breuer-Weil, Aaron; Almasoud, Naif Nasser; Abbasi, Badaruddin; Yetisen, Ali K; Yun, Seok-Hyun; Butt, Haider

    2016-12-01

    Photonic crystals and band gap materials act as manipulators of light and have a plethora of applications. They are made up of stacks of alternating dielectric constants. This article shows the simulations of an inclined, one dimensional and tuneble photonic crystal, using numerical finite element methods. The photonic crystal was made up of silver nanoparticles embedded in a hydrogel matrix and it has the ability to change and recover its periodicity. A series of factors concerning the geometry of the lattice were tested in order to analyze the efficiency, performance and optimize the properties of the optical sensor. These factors range from the size of the nanoparticles and their density within the stacks, to observing the effect of diffraction angle in readouts. PMID:27000025

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

    SciTech Connect

    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

  9. 1D Metallo-Dielectric Photonic Crystals as Selective Emitters for Thermophotovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Narayanaswamy, Arvind; Cybulski, James; Chen, Gang

    2004-11-01

    Spectrally selective thermal radiators that are easy to fabricate is a key ingredient in increasing the efficiency of thermophotovoltaic energy converters. 2D and 3D photonic crystals have been proposed as selective emitters with good control over spectral emission and fabricated. Due to their structural complexity, they are difficult to fabricate. 1D photonic crystals have not been analyzed completely for their spectral emission characteristics. Using a method of dyadic Green's function technique and the fluctuation-dissipation theorem, we have analyzed thermal emission from planarly layered periodic media. 1D photonic crystals made of alternate layers of ultra-thin metallic films in-between dielectric layers exhibit selective emission properties ideal for thermophotovoltaic applications with GaSb photovoltaic cells. By varying the thickness of the dielectric layer, the frequency around which the emitters transitions from lower emissivity to higher emissivity can be altered. It is possible to increase this transition frequency to optical frequencies by replacing the metallic film with a high band gap semiconductor like SiC. Preliminary results from experiments on 1D photonic crystals made of alternating layers of tungsten and alumina will be presented.

  10. Tunable Design of Structural Colors Produced by Pseudo-1D Photonic Crystals of Graphene Oxide.

    PubMed

    Tong, Liping; Qi, Wei; Wang, Mengfan; Huang, Renliang; Su, Rongxin; He, Zhimin

    2016-07-01

    It is broadly observed that graphene oxide (GO) films appear transparent with a thickness of about several nanometers, whereas they appear dark brown or almost black with thickness of more than 1 μm. The basic color mechanism of GO film on a sub-micrometer scale, however, is not well understood. This study reports on GO pseudo-1D photonic crystals (p1D-PhCs) exhibiting tunable structural colors in the visible wavelength range owing to its 1D Bragg nanostructures. Striking structural colors of GO p1D-PhCs could be tuned by simply changing either the volume or concentration of the aqueous GO dispersion during vacuum filtration. Moreover, the quantitative relationship between thickness and reflection wavelength of GO p1D-PhCs has been revealed, thereby providing a theoretical basis to rationally design structural colors of GO p1D-PhCs. The spectral response of GO p1D-PhCs to humidity is also obtained clearly showing the wavelength shift of GO p1D-PhCs at differently relative humidity values and thus encouraging the integration of structural color printing and the humidity-responsive property of GO p1D-PhCs to develop a visible and fast-responsive anti-counterfeiting label. The results pave the way for a variety of potential applications of GO in optics, structural color printing, sensing, and anti-counterfeiting. PMID:27171200

  11. Label-free optical detection of bacteria on a 1-D photonic crystal of porous silicon

    NASA Astrophysics Data System (ADS)

    Wu, Chia-Chen; Alvarez, Sara D.; Rang, Camilla U.; Chao, Lin; Sailor, Michael J.

    2009-02-01

    The construction of a specific, label-free, bacteria biosensor using porous silicon 1-D photonic crystals will be described. Bacteria resident on the surface of porous silicon act as scattering centers for light resonant with the photonic crystal; the diffusely scattered light possesses the optical spectrum of the underlying photonic crystal. Using a spectrometer fitted to a light microscope, the bacteria are imaged without using exogenous dyes or labels and are quantified by measuring the intensity of scattered light. In order to selectively bind and identify bacteria using porous Si, we use surface modifications to reduce nonspecific binding to the surface and to engineer bacteria specificity onto the surface. Bovine serum albumin (BSA) was adsorbed to the porous Si surface to reduce nonspecific binding of bacteria. The coatings were then chemically activated to immobilize polyclonal antibodies specific to Escherichia coli. Two E. coli strains were used in our study, E. coli DH5α and non-pathogenic enterohemorrhagic Escherichia coli (EHEC) strain. The nonpathogenic Vibrio cholerae O1 strain was used to test for antibody specificity. Successful attachment of antibodies was measured using fluorescence microscopy and the scattering method was used to test for bacteria binding specificity.

  12. Refractive Index Sensor Based on a 1D Photonic Crystal in a Microfluidic Channel

    PubMed Central

    Nunes, Pedro S.; Mortensen, Niels Asger; Kutter, Jörg P.; Mogensen, Klaus B.

    2010-01-01

    A refractive index sensor has been fabricated in silicon oxynitride by standard UV lithography and dry etching processes. The refractive index sensor consists of a 1D photonic crystal (PhC) embedded in a microfluidic channel addressed by fiber-terminated planar waveguides. Experimental demonstrations performed with several ethanol solutions ranging from a purity of 96.00% (n = 1.36356) to 95.04% (n = 1.36377) yielded a sensitivity (Δλ/Δn) of 836 nm/RIU and a limit of detection (LOD) of 6 × 10−5 RIU, which is, however, still one order of magnitude higher than the theoretical lower limit of the limit of detection 1.3 × 10−6 RIU. PMID:22294930

  13. Photonic Crystals: Tunable Design of Structural Colors Produced by Pseudo-1D Photonic Crystals of Graphene Oxide (Small 25/2016).

    PubMed

    Tong, Liping; Qi, Wei; Wang, Mengfan; Huang, Renliang; Su, Rongxin; He, Zhimin

    2016-07-01

    The production of structural colors based on graphene oxide (GO) pseudo-one-dimensional photonic crystals (p1D-PhCs) in the visible spectrum is reported on page 3433 by W. Qi and co-workers. The structural colors could be tuned by simply changing either the volume or concentration of the aqueous GO dispersion. Moreover, GO p1D-PhCs exhibit visible and rapid responsiveness to humidity. PMID:27364309

  14. Layer-by-Layer Approach to (2+1)D Photonic Crystal Superlattice with Enhanced Crystalline Integrity.

    PubMed

    Zhang, Lijing; Xiong, Zhuo; Shan, Liang; Zheng, Lu; Wei, Tongbo; Yan, Qingfeng

    2015-10-01

    Large-area polystyrene (PS) colloidal monolayers with high mechanical strength are created by a combination of the air/water interface self-assembly and the solvent vapor annealing technique. Layer-by-layer (LBL) stacking of these colloidal monolayers leads to the formation of (2+1)D photonic crystal superlattice with enhanced crystalline integrity. By manipulating the diameter of PS spheres and the repetition period of the colloidal monolayers, flexible control in structure and stop band position of the (2+1)D photonic crystal superlattice has been realized, which may afford new opportunities for engineering photonic bandgap materials. Furthermore, an enhancement of 97.3% on light output power of a GaN-based light emitting diode is demonstrated when such a (2+1)D photonic crystal superlattice employed as a back reflector. The performance enhancement is attributed to the photonic bandgap enhancement and good angle-independence of the (2+1)D photonic crystal superlattice. PMID:26179658

  15. Enhanced ODR range using exponentially graded refractive index profile of 1D binary photonic crystal

    NASA Astrophysics Data System (ADS)

    Sharma, Sanjeev; Kumar, Rajendra; Singh, Kh. S.; Jain, Deepti; Kumar, Arun

    2016-05-01

    A simple design of broadband one dimensional dielectric/semiconductor multilayer structure having refractive index profile of exponentially graded material has been proposed. The theoretical analysis shows that the proposed structure works as a perfect mirror within a certain wavelength range (1550 nm). In order to calculate the reflection properties a transfer matrix method (TMM) has been used. This property shows that binary graded photonic crystal structures have widened omnidirectional reflector (ODR) bandgap. Hence a exponentially graded photonic crystal structure can be used as a broadband optical reflector and the range of reflection can be tuned to any wavelength region by varying the refractive index profile of exponentially graded photonic crystal structure.

  16. A tiny gas-sensor system based on 1D photonic crystal

    NASA Astrophysics Data System (ADS)

    Bouzidi, A.; Bria, D.; Akjouj, A.; Pennec, Y.; Djafari-Rouhani, B.

    2015-12-01

    We present a gas monitoring system for detecting the gas concentration in ambient air. This sensor is based on a 1D photonic crystal formed by alternating layers of magnesium fluoride (MgF2) and silicon (Si) with an empty layer in the middle. The lamellar cavity (defect layer) will be filled with polluted air that has a refractive index close to that of pure air, varying between n 0  =  1.00 to n 0  =  1.01. The transmission spectrum of this sensor is calculated by the Green function approach. The numerical results show that the transmission peak, which appears in the gap, is caused by the infiltration of impure air into the empty middle layer. This transmission peak can be used for detection purposes in real-time environmental monitoring. The peak frequency is sensitive to the air-gas mixture, and a variation in the refractive index as small as Δn  =  10-5 can be detected. A sensitivity, Δλ/Δn, of 700 nm per refractive index unit (RIU) is achieved with this sensor.

  17. Ultra-fast optical switches using 1D polymeric photonic crystals

    NASA Astrophysics Data System (ADS)

    Katouf, R.; Komikado, T.; Itoh, M.; Yatagai, T.; Umegaki, S.

    2005-12-01

    We report fabrication of ultra-fast optical switches operated at a wavelength of 1064 nm using spin-coated one-dimensional polymeric photonic crystals doped with nonlinear-optical dyes. The optical switches are controlled either by an applied electric-field voltage or by a pump light by use of two different optical-configurations. The response time of the electro-optic switch and the all-optical switch are limited by the applied voltage and the laser used, respectively. The polymeric photonic crystals can be easily fabricated with low cost.

  18. Study of optical reflectance properties in 1D annular photonic crystal containing double negative (DNG) metamaterials

    NASA Astrophysics Data System (ADS)

    Srivastava, Sanjeev K.; Aghajamali, Alireza

    2016-05-01

    Theoretical investigation of photonic band gaps or reflection bands in one-dimensional annular photonic crystal (APC) containing double negative (DNG) metamaterials and air has been presented. The proposed structure consists of the alternate layers of dispersive DNG material and air immersed in free space. In order to study photonic band gaps we obtain the reflectance spectrum of the annular PC by employing the transfer matrix method (TMM) in the cylindrical waves for both TE and TM polarizations. In this work we study the effect of azimuthal mode number (m) and starting radius (ρ0) on the three band gaps viz. zero averaged refractive index (zero-nbar) gap, zero permittivity (zero- ε) and zero permeability (zero- μ) gaps. It is found that for m ≥ 1 , zero- μ gap appears in TE mode and zero- ε gap appears in TM mode. The width of both zero- μ and zero- ε gap increases by increasing m values, but the enhancement of zero- μ gap is more appreciable. Also, the effect of ρ0 on the three band gaps (reflection bands) of annular PC structure at the given m-number has been studied, for both TE and TM polarizations. The result shows that in both polarizations zero- ε and zero- μ gaps decreases when ρ0 increases, whereas zero-nbar gap remains invariant.

  19. Band-edge lasing and miniband lasing in 1-D dual-periodic photonic crystal

    NASA Astrophysics Data System (ADS)

    Ying, Cui-Feng; Zhou, Wen-Yuan; Li, Yi; Ye, Qing; Zhang, Chun-Ping; Tian, Jian-Guo

    2012-06-01

    Herein, we report two different dual-periodic Photonic Crystals (PCs) in dichromated gelatin emulsion which are fabricated by four-beam holography and double-exposure holography. The minibands with high Q-factors have been evidently located in both two structures. By taking into account the non-uniform distribution of material, the numerical results agree quite well with the experimental results. We also compared the band-edge lasing in single-periodic PC and miniband lasing in Moiré dual-periodic PC. Due to extremely flat dispersion and large mode volume of the miniband, high optical conversion efficiency in miniband lasing is achieved as compared with that of band-edge lasing. Such effect may provide potential applications in low-threshold lasers and ultra-sensitive fluorescent probes in biological assays.

  20. Sub-wavelength focusing of cylindrical vector beams by a 1D metallic photonic crystal plano-concave lens

    NASA Astrophysics Data System (ADS)

    Zhong, Yi; Wang, Jin; Xu, Ji

    2014-10-01

    The fine manipulations of cylindrical vector beams (CVBs) based on metallic microstructures, such as sub-wavelength focusing, have entered many interdisciplinary areas, and the important applications have been found in many fields including optical micromanipulation, super-resolution imaging, micro-machining and so on. But so far, the sub-wavelength focusing of azimuthally polarized beams is encountered, since the manipulation mechanisms rely heavily on the excitation of surface plasmon polaritons, which brings the polarization limitation. We theoretically investigated the focusing behavior of CVBs in 1D metallic photonic crystals (MPCs). The simulation results show that a 1D MPC plano-concave lens can focus cylindrical vector beams into scale of sub-wavelength. The negative refraction at the interface between the air and the 1D MPC is analyzed at the frequencies corresponding to the second photonic band, which makes the 1D MPC has the ability to focus higher Fourier components of light beams. The cylindrical plano-concave structure is constructed to focus the radially and azimuthally polarized beams simultaneously. The behavior is demonstrated by Finite Element Method (FEM). The shape of focusing field can be tailored, by changing the polarization ratio of the incident beams. In addition, the effective sub-wavelength focusing phenomenon can also be realized in variety of wave ranges, by choosing the proper materials and adjusting the parameters. We believe that it's the first time to realize the simultaneous sub-wavelength focusing of radially and azimuthally polarized beams, the application of which is quite promising in broad prospects.

  1. Pressure, temperature and plasma frequency effects on the band structure of a 1D semiconductor photonic crystal

    NASA Astrophysics Data System (ADS)

    González, Luz E.; Porras-Montenegro, N.

    2012-01-01

    In this work using the transfer-matrix formalism we study pressure, temperature and plasma frequency effects on the band structure of a 1D semiconductor photonic crystal made of alternating layers of air and GaAs. We have found that the temperature dependence of the photonic band structure is negligible, however, its noticeable changes are due mainly to the variations of the width and the dielectric constant of the layers of GaAs, caused by the applied hydrostatic pressure. On the other hand, by using the Drude's model, we have studied the effects of the hydrostatic pressure by means of the variation of the effective mass and density of the carriers in n-doped GaAs, finding firstly that increasing the amount of n-dopants in GaAs, namely, increasing the plasma frequency, the photonic band structure is shifted to regions of higher frequencies, and secondly the appearance of two regimes of the photonic band structure: one above the plasma frequency with the presence of usual Bragg gaps, and the other, below this frequency, where there are no gaps regularly distributed, with their width diminishing with the increasing of the plasma frequency as well as with the appearance of more bands, but leaving a wide frequency range in the lowest part of the spectrum without accessible photon states. Also, we have found characteristic frequencies in which the dielectric constant equals for different applied pressures, and from which to higher or lower values the photonic band structure inverts its behavior, depending on the value of the applied hydrostatic pressure. We hope this work may be taken into account for the development of new perspectives in the design of new optical devices.

  2. Selectivity, cycling stability and temperature dependence of touchless finger motion tracking devices based on 1D photonic crystals

    NASA Astrophysics Data System (ADS)

    Szendrei, Katalin; Ganter, Pirmin; Lotsch, Bettina V.

    2016-04-01

    We report on the humidity-induced swelling behavior of thin film devices composed of 2D phosphatoantimonate nanosheets and study their water uptake mechanism by means of ellipsometric porosimetry. Ambient humidity changes cause significant swelling in thin films composed of turbostratically disordered H3Sb3P2O14 nanosheets through water uptake between the nanosheet layers. This phenomenon is exploited to construct humidity responsive colorimetric sensors based on 1D Photonic Crystals. We demonstrate the ultrahigh sensitivity of H3Sb3P2O14/SiO2 Bragg stacks to ambient humidity, as well as reversible transparency switching as a consequence of refractive index matching at high relative humidities. The Photonic Crystals show substantially higher sensitivity to humidity as compared to ethanol vapor, reflecting the less favorable interaction of ethanol with the nanosheet layers as compared to water. Based on their ultrahigh sensitivity to humidity, phosphatoantimonate nanosheet based Bragg stacks can be used to track the motion of a finger by responding to its humidity sheath, without the finger touching the sensor surface. The cycling stability of such optical touchless positioning interfaces as well as the reversibility of the sensing event was demonstrated for more than 100 cycles. While the dew point presents an inherent lower limit to the sensor performance, the sensing ability remains essentially unaffected at elevated temperatures up to 40 °C.

  3. Mode stability in photonic-crystal surface-emitting lasers with large κ{sub 1D}L

    SciTech Connect

    Liang, Yong Okino, Tsuyoshi; Ishizaki, Kenji; Noda, Susumu; Kitamura, Kyoko; Peng, Chao

    2014-01-13

    We study mode stability in photonic-crystal surface-emitting lasers (PCSELs) with large coupling-coefficient-length product κ{sub 1D}L(>6). We observe that mode competition occurs at high current levels above threshold. Our combined experimental and theoretical study provides the first evidence of the mode competition originating from the high-order band-edge modes. The decreased threshold margin between these competing high-order modes and the main lasing mode with increasing cavity length as well as the spatial hole burning effect may deteriorate the single-mode stability. Our finding is essential for designing single-mode high-power PCSELs for which the strategy to suppress the high-order modes must be considered.

  4. Transverse-electric/transverse-magnetic polarization converter using 1D finite biaxial photonic crystal.

    PubMed

    Ouchani, Noama; Bria, Driss; Djafari-Rouhani, Bahram; Nougaoui, Abdelkarim

    2007-09-01

    We show that by using a one-dimensional anisotropic photonic structure, it is possible to realize optical wave polarization conversion by reflection and transmission processes. Thus a single incident S(P) polarized plane wave can produce a single reflected P(S) polarized wave and a single transmitted P(S) polarized wave. This polarization conversion property can be fulfilled with a simple finite superlattice (SL) constituted of anisotropic dielectric materials. We discuss the appropriate choices of the material and geometrical properties to realize such structures. The transmission and reflection coefficients are calculated in the framework of the Green's function method. The amplitude and the polarization characteristics of reflected and transmitted waves are determined as functions of frequency, wave vector k(parallel) (parallel to the interface), and the orientations of the principal axes of the layers constituting the SL. Specific applications of these results are given for a SL consisting of alternating biaxial anisotropic layers NaNO(2)/SbSI sandwiched between two identical semi-infinite isotropic media. PMID:17767240

  5. New method for computation of band structures in 1D photonic crystals based on the Fresnel equations

    NASA Astrophysics Data System (ADS)

    Roshan Entezar, S.

    2013-02-01

    In this paper, we present a new method for calculation of band structure in one-dimensional bilayer photonic crystals, based on the Fresnel equations. We derive a new relation to obtain the band structure without using the Floquet theorem. It is shown that this relation can be simplified under the assumption that the single-path phase-shift acquired through the individual layers of the photonic crystal be equal to ? . The results obtained by our method are compared with the ones obtained from the transfer matrix method to show that they are exactly identical.

  6. The effect of magnetic field on bistability in 1D photonic crystal doped by magnetized plasma and coupled nonlinear defects

    SciTech Connect

    Mehdian, H.; Mohammadzahery, Z.; Hasanbeigi, A.

    2014-01-15

    In this work, we study the defect mode and bistability behavior of 1-D photonic band gap structure with magnetized plasma and coupled nonlinear defects. The transfer matrix method has been employed to investigate the magnetic field effect on defect mode frequency and bistability threshold. The obtained results show that the frequency of defect mode and bistability threshold can be altered, without changing the structure of the photonic multilayer. Therefore, the bistability behavior of the subjected structure in the presence of magnetized plasma can be utilized in manufacturing wide frequency range devices.

  7. Temperature dependent transmission and optical bistability in a 1D photonic crystal with a liquid crystal defect layer

    NASA Astrophysics Data System (ADS)

    Roshan Entezar, Samad; Madani, Amir; Karimi Habil, Mojtaba; Namdar, Abdolrahman; Tajalli, Habib

    2013-12-01

    The transmission properties of a one-dimensional periodic structure with anisotropic defect layer is investigated using a ? transfer matrix method. A layer of homogeneously aligned nematic liquid crystal is taken as a defect. We show that the frequency and polarization of the defect mode is modified by changing the operating temperature and liquid crystal orientation. Also the temperature dependent nonlinear response of the defect structure is investigated. It is shown that the threshold intensity needed to achieve the bistability depends on the operating temperature. So, the structure can be used as a thermal switch at the frequency near the defect mode.

  8. Propagation of the Ultra-Short Laser Pulses Through the Helical 1D Photonic Crystal Structure with Twist Defect

    NASA Astrophysics Data System (ADS)

    Antonov, Dmitrii V.; Iegorov, Roman

    2016-02-01

    The presence of the photonic band-gap is a featured property of the cholesteric liquid crystals (CLC). It can be practically realized for almost any reasonable wavelengths with very high degree of tunability. We have investigated theoretically the influence of the twist defect of the CLC helical structure onto the bandwidth-limited ultra-short laser pulse propagating inside the photonic band-gap. The changes of both pulse duration and peak power with defect angle were observed together with pulse acceleration and retardation for a case of normal incidence of the light.

  9. Focus modulation of cylindrical vector beams by using 1D photonic crystal lens with negative refraction effect.

    PubMed

    Xu, Ji; Zhong, Yi; Wang, Shengming; Lu, Yunqing; Wan, Hongdan; Jiang, Jian; Wang, Jin

    2015-10-19

    Sub-wavelength focusing of cylindrical vector beams (CVBs) has attracted great attention due to the specific physical effects and the applications in many areas. More powerful, flexible and effective ways to modulate the focus transversally and also longitudinally are always being pursued. In this paper, cylindrically symmetric lens composed of negative-index one-dimensional photonic crystal is proposed to make a breakthrough. By revealing the relationship between focal length and the exit surface shape of the lens, a quite simple and effective principle of designing the lens structure is presented to realize specific focus modulation. Plano-concave lenses are parameterized to modulate the focal length and the number of focuses. An axicon constructed by one-dimensional photonic crystal is proposed for the first time to obtain a large depth of focus and an optical needle focal field with almost a theoretical minimum FWHM of 0.362λ is achieved under radially polarized incident light. Because of the almost identical negative refractive index for TE and TM polarization states, all the modulation methods can be applied for any arbitrary polarized CVBs. This work offers a promising methodology for designing negative-index lenses in related application areas. PMID:26480359

  10. Near-infrared tunable narrow filter properties in a 1D photonic crystal containing semiconductor metamaterial photonic quantum-well defect

    NASA Astrophysics Data System (ADS)

    Barati, Mahmood; Aghajamali, Alireza

    2016-05-01

    The near-infrared (NIR) narrow filter properties in the transmission spectra of a one-dimensional photonic crystal doped with semiconductor metamaterial photonic quantum-well defect (PQW) were theoretically studied. The behavior of the defect mode as a function of the stack number of the PQW defect structure, the filling factor of semiconductor metamaterial layer, the polarization and the angle of incidence were investigated for Al-doped ZnO (AZO) and ZnO as the semiconductor metamaterial layer. It is found that the frequency of the defect mode can be tuned by variation of the period of the defect structure, polarization, incidence angle, and the filling factor of the semiconductor metamaterial layer. It is also shown that the number of the defect mode is independent of the period of the PQW defect structure and is in sharp contrast with the case where a common dielectric or metamaterial defect are used. The results also show that for both polarizations the defect mode is red-shifted as the number of the defect period and filling factor increase. An opposite trend is observed as the angle of incidence increases. The proposed structure could provide useful information for designing new types of tuneable narrowband filters at NIR region.

  11. Silicon on-chip 1D photonic crystal nanobeam bandstop filters for the parallel multiplexing of ultra-compact integrated sensor array.

    PubMed

    Yang, Daquan; Wang, Chuan; Ji, Yuefeng

    2016-07-25

    We propose a novel multiplexed ultra-compact high-sensitivity one-dimensional (1D) photonic crystal (PC) nanobeam cavity sensor array on a monolithic silicon chip, referred to as Parallel Integrated 1D PC Nanobeam Cavity Sensor Array (PI-1DPC-NCSA). The performance of the device is investigated numerically with three-dimensional finite-difference time-domain (3D-FDTD) technique. The PI-1DPC-NCSA consists of multiple parallel-connected channels of integrated 1D PC nanobeam cavities/waveguides with gap separations. On each channel, by connecting two additional 1D PC nanobeam bandstop filters (1DPC-NBFs) to a 1D PC nanobeam cavity sensor (1DPC-NCS) in series, a transmission spectrum with a single targeted resonance is achieved for the purpose of multiplexed sensing applications. While the other spurious resonances are filtered out by the stop-band of 1DPC-NBF, multiple 1DPC-NCSs at different resonances can be connected in parallel without spectrum overlap. Furthermore, in order for all 1DPC-NCSs to be integrated into microarrays and to be interrogated simultaneously with a single input/output port, all channels are then connected in parallel by using a 1 × n taper-type equal power splitter and a n × 1 S-type power combiner in the input port and output port, respectively (n is the channel number). The concept model of PI-1DPC-NCSA is displayed with a 3-parallel-channel 1DPC-NCSs array containing series-connected 1DPC-NBFs. The bulk refractive index sensitivities as high as 112.6nm/RIU, 121.7nm/RIU, and 148.5nm/RIU are obtained (RIU = Refractive Index Unit). In particular, the footprint of the 3-parallel-channel PI-1DPC-NCSA is 4.5μm × 50μm (width × length), decreased by more than three orders of magnitude compared to 2D PC integrated sensor arrays. Thus, this is a promising platform for realizing ultra-compact lab-on-a-chip applications with high integration density and high parallel-multiplexing capabilities. PMID:27464080

  12. Comprehensive analysis of photonic effects on up-conversion of β-NaYF4:Er3+ nanoparticles in an organic-inorganic hybrid 1D photonic crystal

    NASA Astrophysics Data System (ADS)

    Hofmann, C. L. M.; Fischer, S.; Reitz, C.; Richards, B. S.; Goldschmidt, J. C.

    2016-04-01

    Upconversion (UC) presents a possibility to exploit sub-bandgap photons for current generation in solar cells by creating one high-energy photon out of at least two lower-energy photons. Photonic structures can enhance UC by two effects: a locally increased irradiance and a modified local density of photon states (LDOS). Bragg stacks are promising photonic structures for this application, because they are straightforward to optimize and overall absorption can be increased by adding more layers. In this work, we present a comprehensive simulation-based analysis of the photonic effects of a Bragg stack on UC luminescence. The investigated organic-inorganic hybrid Bragg stack consists of alternating layers of Poly(methylmethacrylate) (PMMA), containing purpose-built β-NaYF4:25% Er3+ core-shell nanoparticles and titanium dioxide (TiO2). From optical characterization of single thin layers, input parameters for simulations of the photonic effects are generated. The local irradiance enhancement and modulated LDOS are first simulated separately. Subsequently they are coupled in a rate equation model of the upconversion dynamics. Using the integrated model, UC luminescence is maximized by adapting the Bragg stack design. For a Bragg stack of only 5 bilayers, UC luminescence is enhanced by a factor of 3.8 at an incident irradiance of 2000 W/m2. Our results identify the Bragg stack as promising for enhancing UC, especially in the low-irradiance regime, relevant for the application in photovoltaics. Therefore, we experimentally realized optimized Bragg stack designs. The PMMA layers, containing UC nanoparticles, are produced via spin-coating from a toluene based solution. The TiO2 layers are produced by atomic layer deposition from molecular precursors. The reflectance measurements show that the realized Bragg stacks are in good agreement with predictions from simulation.

  13. New miniaturized exhaled nitric oxide sensor based on a high Q/V mid-infrared 1D photonic crystal cavity.

    PubMed

    Conteduca, D; Dell'Olio, F; Ciminelli, C; Armenise, M N

    2015-03-20

    A high Q/V mid-infrared 1D photonic crystal cavity in chalcogenide glass AMTIR-1 (Ge33As12Se55) resonating at λR=5.26  μm has been proposed as a key element of a sensor able to evaluate the nitric oxide (NO) concentration in the exhaled breath, namely fraction exhaled NO. The cavity design has been carried out through 3D finite-element method simulations. A Q-factor of 1.1×104 and a mode volume V=0.8  (λ/n)3, corresponding to a Q/V ratio of 1.4×104(λ/n)-3, have been obtained with a resonance transmission coefficient T=15%. A sensitivity of 10 ppb has been calculated with reference to the photothermal physical property of the material. Such a result is lower than the state-of-the-art of NO sensors proposed in literature, where hundreds of parts per trillion-level detection seem to have been achieved, but comparable with the performance obtained by commercial devices. The main advantages of the new device are in terms of footprint (=150  μm2), smaller at least 1 order of magnitude than those in literature, fast response time (only few seconds), and potential low cost. Such properties make possible in a handheld device the sensor integration in a multi-analysis system for detecting the presence of several trace gases, improving prevention, and reducing the duration of drug treatment for asthma and viral infections. PMID:25968502

  14. Control of coupling in 1D photonic crystal coupled-cavity nano-wire structures via hole diameter and position variation

    NASA Astrophysics Data System (ADS)

    Zain, A. R. Md; De La Rue, R. M.

    2015-12-01

    We have successfully demonstrated close experimental control of the resonance splitting/free spectral range of a coupled micro-cavity one-dimensional photonic crystal/photonic wire device structure based on silicon-on-insulator. Clear splitting of the resonances, with FSR values ranging from 8 nm to 48 nm, was obtained through the use of different hole arrangements within the middle section of the device structures, between the coupled cavities. The results show good agreement with calculations obtained using a finite-difference time-domain simulation approach.

  15. Photonic crystal light source

    DOEpatents

    Fleming, James G.; Lin, Shawn-Yu; Bur, James A.

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  16. Single-step fabrication process of 1-D photonic crystals coupled to nanocolumnar TiO2 layers to improve DSC efficiency.

    PubMed

    González-García, L; Colodrero, S; Míguez, H; González-Elipe, A R

    2015-11-30

    The present work proposes the use of a TiO2 electrode coupled to a one-dimensional photonic crystal (1DPC), all formed by the sequential deposition of nanocolumnar thin films by physical vapor oblique angle deposition (PV-OAD), to enhance the optical and electrical performance of DSCs while transparency is preserved. We demonstrate that this approach allows building an architecture combining a non-dispersive 3 µm of TiO2 electrode and 1 µm TiO2-SiO2 1DPC, both columnar, in a single-step process. The incorporation of the photonic structure is responsible for a rise of 30% in photovoltaic efficiency, as compared with a transparent cell with a single TiO2 electrode. Detailed analysis of the spectral dependence of the photocurrent demonstrates that the 1DPC improves light harvesting efficiency by both back reflection and optical cavity modes confinement within the TiO2 films, thus increasing the overall performance of the cell. PMID:26698810

  17. Function photonic crystals

    NASA Astrophysics Data System (ADS)

    Wu, Xiang-Yao; Zhang, Bai-Jun; Yang, Jing-Hai; Liu, Xiao-Jing; Ba, Nuo; Wu, Yi-Heng; Wang, Qing-Cai

    2011-07-01

    In this paper, we present a new kind of function photonic crystals (PCs), whose refractive index is a function of space position. Conventional PCs structure grows from two materials, A and B, with different dielectric constants εA and εB. Based on Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we give the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals, and we find the following: (1) For the vertical and non-vertical incidence light of function photonic crystals, there are band gap structures, and for only the vertical incidence light, the conventional PCs have band gap structures. (2) By choosing various refractive index distribution functions n( z), we can obtain more wider or more narrower band gap structure than conventional photonic crystals.

  18. Dispersion in photonic crystals

    NASA Astrophysics Data System (ADS)

    Witzens, Jeremy

    2005-11-01

    Investigations on the dispersive properties of photonic crystals, modified scattering in ring-resonators, monolithic integration of vertical-cavity surface-emitting lasers and advanced data processing techniques for the finite-difference time-domain method are presented. Photonic crystals are periodic mesoscopic arrays of scatterers that modify the propagation properties of electromagnetic waves in a similar way as "natural" crystals modify the properties of electrons in solid-state physics. In this thesis photonic crystals are implemented as planar photonic crystals, i.e., optically thin semiconductor films with periodic arrays of holes etched into them, with a hole-to-hole spacing of the order of the wavelength of light in the dielectric media. Photonic crystals can feature forbidden frequency ranges (the band-gaps) in which light cannot propagate. Even though most work on photonic crystals has focused on these band-gaps for application such as confinement and guiding of light, this thesis focuses on the allowed frequency regions (the photonic bands) and investigates how the propagation of light is modified by the crystal lattice. In particular the guiding of light in bulk photonic crystals in the absence of lattice defects (the self-collimation effect) and the angular steering of light in photonic crystals (the superprism effect) are investigated. The latter is used to design a planar lightwave circuit for frequency domain demultiplexion. Difficulties such as efficient insertion of light into the crystal are resolved and previously predicted limitations on the resolution are circumvented. The demultiplexer is also fabricated and characterized. Monolithic integration of vertical-cavity surface-emitting lasers by means of resonantly enhanced grating couplers is investigated. The grating coupler is designed to bend light through a ninety-degree angle and is characterized with the finite-difference time-domain method. The vertical-cavity surface-emitting lasers are

  19. Photonic crystal technology for terahertz system integration

    NASA Astrophysics Data System (ADS)

    Fujita, Masayuki; Nagatsuma, Tadao

    2016-04-01

    Developing terahertz integration technology is essential for practical use of terahertz electromagnetic waves (0.1-10 THz) in various applications including broadband wireless communication, spectroscopic sensing, and nondestructive imaging. In this paper, we present our recent challenges towards terahertz system integration based on photonic crystal technology such as the development of terahertz transceivers. We use photonic-crystal slabs consisting of a twodimensional lattice of air holes formed in a silicon slab to develop low loss compact terahertz components in planar structures. The demonstration of ultralow loss (< 0.1 dB/cm) waveguides and integrated transceiver devices in the 0.3 THz band shows the potential for the application of photonic crystals to terahertz integration technology. Improving the coupling efficiency between the photonic crystal waveguide and resonant tunneling diode is important to take full advantage of the ultralow loss photonic crystal waveguides.

  20. One-Dimensional Photonic Crystal Superprisms

    NASA Technical Reports Server (NTRS)

    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.

  1. Nonreciprocity of edge modes in 1D magnonic crystal

    NASA Astrophysics Data System (ADS)

    Lisenkov, I.; Kalyabin, D.; Osokin, S.; Klos, J. W.; Krawczyk, M.; Nikitov, S.

    2015-03-01

    Spin waves propagation in 1D magnonic crystals is investigated theoretically. Mathematical model based on plane wave expansion method is applied to different types of magnonic crystals, namely bi-component magnonic crystal with symmetric/asymmetric boundaries and ferromagnetic film with periodically corrugated top surface. It is shown that edge modes in magnonic crystals may exhibit nonreciprocal behaviour at much lower frequencies than in homogeneous films.

  2. Tunable electrochromic photonic crystals

    NASA Astrophysics Data System (ADS)

    Kuai, Su-Lan; Bader, Georges; Ashrit, P. V.

    2005-05-01

    Photonic crystals based on the electrochromic phenomenon have been fabricated and proposed for band gap tuning. Electrochromic tungsten trioxide (WO3) inverse opals have been fabricated by polystyrene colloidal crystal templating. The WO3 matrix was obtained through a dip-infiltrating sol-gel process, with subsequent removal of the polymer microspheres by calcination. Scanning electron micrographs confirm the ordering of the hexagonal macroporous structure. The reflection spectra show two pronounced Bragg diffraction peaks. By inserting lithium into the crystals, the first reflection peak shifts gradually toward shorter wavelength for 36 nm, while the second reflection peak shifts toward longer wavelength for about 28 nm. This should be of great interest for photonic device applications.

  3. Photonic Crystal Nanocavity Lasers

    NASA Astrophysics Data System (ADS)

    Scherer, Axel

    2001-03-01

    Two- and three-dimensional microfabricated mirrors are generally referred to as photonic bandgap (PBG) crystals, and can be lithographically constructed to match a given frequency to confine light to very small volumes.1 For mirrors matching light emission at 1550nm, the lattice parameter a should correspond to 500nm, and the radius of the holes should be 180nm. By combining the slab waveguide design from microdisk lasers with the concept of microfabricating Bragg reflectors around a 2-D Fabry-Perot structure, we arrive at the design for ultra-small sub-3 optical nanocavity photonic crystal lasers. The mode volume in these laser cavities can be as small as 2.5 cubic half wavelengths or 0.03m3, and spontaneous emission in the cavity can be very efficiently coupled into the lasing mode. This efficient coupling in turn results in significant advantages of these nanocavity lasers over devices with larger mode volumes, as high modulation speed and very low threshold power light emission are expected. If the photonic crystal is designed appropriately and is not too porous, it is also possible to efficiently guide light within the perforated slab and to minimize diffraction losses. This waveguiding within a photonic crystal provides us with an opportunity to couple light from one cavity to another, or into connecting waveguides. By creating two-dimensional photonic crystals, which are microfabricated into InGaAsP slabs, we have recently defined the smallest lasers to date. When combined with high index contrast slabs in which light can be efficiently guided, microfabricated two-dimensional photonic bandgap mirrors provide the geometries needed to confine light into extremely small volumes with high Q.1,2,3,4 Two-dimensional Fabry-Perot resonators with microfabricated mirrors are formed when defects are introduced into the periodic photonic bandgap structure. It is then possible to tune these cavities lithographically by changing the precise geometry of the microstructures

  4. Zero-n gap in one dimensional photonic crystal

    NASA Astrophysics Data System (ADS)

    Chobey, Mahesh K.; Suthar, B.

    2016-05-01

    We study a one-dimensional (1-D) photonic crystal composed of Double Positive (DPS) and Double Negative (DNG) material. This structure shows omnidirectional photonic bandgap, which is insensitive with angle of incidence and polarization. To study the effect of structural parameters on the photonic band structure, we have calculated photonic band gap at various thicknesses of DPS and DNG.

  5. Slotted photonic crystal biosensors

    NASA Astrophysics Data System (ADS)

    Scullion, Mark Gerard

    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 result in poor overlap of the optical field with the target molecules, reducing the maximum sensitivity achievable. This thesis presents a new platform for optical biosensors, namely slotted photonic crystals, which engender higher sensitivities due to their ability to confine, spatially and temporally, the peak of optical mode 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. High sensitivities were observed in smaller structures than most competing devices in the literature. Initial tests with cellular material for real applications was also performed, and shown to be of promise. In addition, groundwork to make an integrated device that includes the spectrometer function was also carried out showing that slotted photonic crystals themselves can be used for on-chip wavelength specific filtering and spectroscopy, whilst gas-free microvalves for automation were also developed. 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.

  6. Hydrophobic photonic crystal fibers.

    PubMed

    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

  7. Slotted photonic crystal sensors.

    PubMed

    Scullion, Mark G; Krauss, Thomas F; Di Falco, Andrea

    2013-01-01

    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. PMID:23503295

  8. Slotted Photonic Crystal Sensors

    PubMed Central

    Scullion, Mark G.; Krauss, Thomas F.; Di Falco, Andrea

    2013-01-01

    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. PMID:23503295

  9. Photonic Crystal Laser Accelerator Structures

    SciTech Connect

    Cowan, Benjamin M

    2003-05-21

    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 optical mode in an all-dielectric structure, eliminating the need for metals and their characteristic losses at optical frequencies. We discuss several geometries of photonic crystal accelerator structures. Photonic crystal fibers (PCFs) are optical fibers which can confine a speed-of-light optical mode in vacuum. Planar structures, both two- and three-dimensional, can also confine such a mode, and have the additional advantage that they can be manufactured using common microfabrication techniques such as those used for integrated circuits. This allows for a variety of possible materials, so that dielectrics with desirable optical and radiation-hardness properties can be chosen. We discuss examples of simulated photonic crystal structures to demonstrate the scaling laws and trade-offs involved, and touch on potential fabrication processes.

  10. Natural photonic crystals

    NASA Astrophysics Data System (ADS)

    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.

  11. Photonic crystal microspheres

    NASA Astrophysics Data System (ADS)

    Zhokhov, A. A.; Masalov, V. M.; Sukhinina, N. S.; Matveev, D. V.; Dolganov, P. V.; Dolganov, V. K.; Emelchenko, G. A.

    2015-11-01

    Spherical samples of photonic crystals formed by colloidal SiO2 nanoparticles were synthesized. Synthesis of microspheres from 160 nm, 200 nm and 430 nm diameter colloidal nanoparticles was performed over a wide size range, from 5 μm to 50 μm. The mechanism of formation of void microparticles exceeding 50 μm is discussed. The spectral measurements verified the association of the spectra with the peaks of selective reflection from the cubic lattice planes. The microparticle morphology is characterized by scanning electron microscopy (SEM).

  12. Optics of globular photonic crystals

    SciTech Connect

    Gorelik, V S

    2007-05-31

    The results of experimental and theoretical studies of the optical properties of globular photonic crystals - new physical objects having a crystal structure with the lattice period exceeding considerably the atomic size, are presented. As globular photonic crystals, artificial opal matrices consisting of close-packed silica globules of diameter {approx}200 nm were used. The reflection spectra of these objects characterising the parameters of photonic bands existing in these crystals in the visible spectral region are presented. The idealised models of the energy band structure of photonic crystals investigated in the review give analytic dispersion dependences for the group velocity and the effective photon mass in a globular photonic crystal. The characteristics of secondary emission excited in globular photonic crystals by monochromatic and broadband radiation are presented. The results of investigations of single-photon-excited delayed scattering of light observed in globular photonic crystals exposed to cw UV radiation and radiation from a repetitively pulsed copper vapour laser are presented. The possibilities of using globular photonic crystals as active media for lasing in different spectral regions are considered. It is proposed to use globular photonic crystals as sensitive sensors in optoelectronic devices for molecular analysis of organic and inorganic materials by the modern methods of laser spectroscopy. The results of experimental studies of spontaneous and stimulated globular scattering of light are discussed. The conditions for observing resonance and two-photon-excited delayed scattering of light are found. The possibility of accumulation and localisation of the laser radiation energy inside a globular photonic crystal is reported. (review)

  13. Photonic crystal and photonic wire device structures

    NASA Astrophysics Data System (ADS)

    De La Rue, Richard; Sorel, Marc; Johnson, Nigel; Rahman, Faiz; Ironside, Charles; Cronin, Lee; Watson, Ian; Martin, Robert; Jin, Chongjun; Pottier, Pierre; Chong, Harold; Gnan, Marco; Jugessur, Aju; Camargo, Edilson; Erwin, Grant; Md Zain, Ahmad; Ntakis, Iraklis; Hobbs, Lois; Zhang, Hua; Armenise, Mario; Ciminelli, Caterina; Coquillat, Dominique

    2005-09-01

    Photonic devices that exploit photonic crystal (PhC) principles in a planar environment continue to provide a fertile field of research. 2D PhC based channel waveguides can provide both strong confinement and controlled dispersion behaviour. In conjunction with, for instance, various electro-optic, thermo-optic and other effects, a range of device functionality is accessible in very compact PhC channel-guide devices that offer the potential for high-density integration. Low enough propagation losses are now being obtained with photonic crystal channel-guide structures that their use in real applications has become plausible. Photonic wires (PhWs) can also provide strong confinement and low propagation losses. Bragg-gratings imposed on photonic wires can provide dispersion and frequency selection in device structures that are intrinsically simpler than 2D PhC channel guides--and can compete with them under realistic conditions.

  14. Cholesteric liquid crystal photonic crystal lasers and photonic devices

    NASA Astrophysics Data System (ADS)

    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

  15. Photonic crystals with active organic materials

    NASA Astrophysics Data System (ADS)

    Wu, Yeheng

    The concept of photonic crystals, which involves periodically arranged dielectrics that form a new type of material having novel photonic properties, was first proposed about two decades ago. Since then, a number of applications in photonic technology have been explored. Specifically, organic and hybrid photonic crystals are promising because of the unique advantages of the organic materials. A one-dimensional (1D) photonic crystal (multilayer) has high reflectance across a certain wavelength range. We report on studies of 1D multilayer polymer films that were fabricated using spin-coating, free film stacking, and co-extrusion techniques. For example, a stack fabricated by placing a laser dye-doped gain medium between two multilayer reflecting polymer films forms a micro-resonator laser or distributed Bragg laser. The resulting laser system is made entirely of plastic and is only several tens of micrometers in thickness. When the gain, a dye-doped medium, comprises one type of a two-type multilayer film, it results a laser exhibiting distributed feedback. At the edge of the photonic band, the group velocity becomes small and the density of photon states becomes high, which leads to laser emission. Such distributed feedback lasers were fabricated using the co-extrusion technique. The refractive indices and the photonic lattice determine the photonic band gap, which can be tuned by changing these parameters. Materials with Kerr nonlinearity exhibit a change in refractive index depending on the incident intensity of the light. To demonstrate such switching, electrochemical etching techniques on silicon wafers were used to form two-dimensional (2D) photonic crystals. By incorporating the nonlinear organic material into the 2D structure, we have made all-optical switches. The reflection of a beam from the 2D photonic crystal can be controlled by another beam because it induces a refractive index change in the active material by altering the reflection band. A mid

  16. Photonic Crystal Nanolaser Biosensors

    NASA Astrophysics Data System (ADS)

    Kita, Shota; Otsuka, Shota; Hachuda, Shoji; Endo, Tatsuro; Imai, Yasunori; Nishijima, Yoshiaki; Misawa, Hiroaki; Baba, Toshihiko

    High-performance and low-cost sensors are critical devices for high-throughput analyses of bio-samples in medical diagnoses and life sciences. In this paper, we demonstrate photonic crystal nanolaser sensor, which detects the adsorption of biomolecules from the lasing wavelength shift. It is a promising device, which balances a high sensitivity, high resolution, small size, easy integration, simple setup and low cost. In particular with a nanoslot structure, it achieves a super-sensitivity in protein sensing whose detection limit is three orders of magnitude lower than that of standard surface-plasmon-resonance sensors. Our investigations indicate that the nanoslot acts as a protein condenser powered by the optical gradient force, which arises from the strong localization of laser mode in the nanoslot.

  17. Strongly-Refractive One-Dimensional Photonic Crystal Prisms

    NASA Technical Reports Server (NTRS)

    Ting, David Z. (Inventor)

    2004-01-01

    One-dimensional (1D) photonic crystal prisms can separate a beam of polychromatic electromagnetic waves into constituent wavelength components and can utilize unconventional refraction properties for wavelength dispersion over significant portions of an entire photonic band rather than just near the band edges outside the photonic band gaps. Using a ID photonic crystal simplifies the design and fabrication process and allows the use of larger feature sizes. The prism geometry broadens the useful wavelength range, enables better optical transmission, and exhibits angular dependence on wavelength with reduced non-linearity. The properties of the 1 D photonic crystal prism can be tuned by varying design parameters such as incidence angle, exit surface angle, and layer widths. The ID photonic crystal prism can be fabricated in a planar process, and can be used as optical integrated circuit elements.

  18. Integrated multicolor detector utilizing 1D photonic bandgap filter with wedge-shaped defect

    NASA Astrophysics Data System (ADS)

    Jaksic, Zoran S.; Petrovic, Radomir; Randjelovic, Danijela; Dankovic, Tatjana; Djuric, Zoran G.; Ehrfeld, Wolfgang; Schmidt, Andreas; Hecker, Karl H.

    1999-03-01

    We propose a single-chip multicolor photodetector for micrometers range based on a linear IR semiconductor detector array with an integrated 1D photonic bandgap (PBG) filter. A wedge- shaped defect slab is introduced into the filer instead of one of the layers. The bandgap of the photonic crystal coincides with the spectral sensitivity range of the photodetector array, while the built-in defect gives a transmission peak within the same range. The defect thickness varies along the array length and thus shifts the transmission peak wavelength. The optimized photonic bandgap filter including defect is designed using the transfer matrix method. The peak frequency is tuned by choosing the geometrical parameters of the wedge-shaped defect. In our experiments, thin alternating Si and SiO2 films are sputtered onto the array surface, thus forming a 1D PBG structure. The defect is fabricated by gradually changing the middle Si layer thickness over the width of the array. Its wedge-forming is performed by micromachining or, alternatively, by in-situ oblique deposition within the sputtering system and, possibly, subsequent chemomechanical polishing. The characteristics of the finished PBG structure are measured using an IR spectrophotometer. An increase of the number of PBG layers improves the confinement of transmission peaks and thus decreases the crosstalk between the array elements. Although our multicolor detector is designed for the (3-5) micrometers atmospheric window, it can be straightforward redesigned for any other optical range.

  19. Spherical colloidal photonic crystals.

    PubMed

    Zhao, Yuanjin; Shang, Luoran; Cheng, Yao; Gu, Zhongze

    2014-12-16

    CONSPECTUS: Colloidal photonic crystals (PhCs), periodically arranged monodisperse nanoparticles, have emerged as one of the most promising materials for light manipulation because of their photonic band gaps (PBGs), which affect photons in a manner similar to the effect of semiconductor energy band gaps on electrons. The PBGs arise due to the periodic modulation of the refractive index between the building nanoparticles and the surrounding medium in space with subwavelength period. This leads to light with certain wavelengths or frequencies located in the PBG being prohibited from propagating. Because of this special property, the fabrication and application of colloidal PhCs have attracted increasing interest from researchers. The most simple and economical method for fabrication of colloidal PhCs is the bottom-up approach of nanoparticle self-assembly. Common colloidal PhCs from this approach in nature are gem opals, which are made from the ordered assembly and deposition of spherical silica nanoparticles after years of siliceous sedimentation and compression. Besides naturally occurring opals, a variety of manmade colloidal PhCs with thin film or bulk morphology have also been developed. In principle, because of the effect of Bragg diffraction, these PhC materials show different structural colors when observed from different angles, resulting in brilliant colors and important applications. However, this angle dependence is disadvantageous for the construction of some optical materials and devices in which wide viewing angles are desired. Recently, a series of colloidal PhC materials with spherical macroscopic morphology have been created. Because of their spherical symmetry, the PBGs of spherical colloidal PhCs are independent of rotation under illumination of the surface at a fixed incident angle of the light, broadening the perspective of their applications. Based on droplet templates containing colloidal nanoparticles, these spherical colloidal PhCs can be

  20. Configurable silicon photonic crystal waveguides

    SciTech Connect

    Prorok, Stefan; Petrov, Alexander; Eich, Manfred; Luo, Jingdong; Jen, Alex K.-Y.

    2013-12-23

    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.

  1. Multicolor photonic crystal laser array

    SciTech Connect

    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.

  2. Configurable silicon photonic crystal waveguides

    NASA Astrophysics Data System (ADS)

    Prorok, Stefan; Petrov, Alexander; Eich, Manfred; Luo, Jingdong; Jen, Alex K.-Y.

    2013-12-01

    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.

  3. Spatial filtering with photonic crystals

    SciTech Connect

    Maigyte, Lina; Staliunas, Kestutis

    2015-03-15

    Photonic crystals are well known for their celebrated photonic band-gaps—the forbidden frequency ranges, for which the light waves cannot propagate through the structure. The frequency (or chromatic) band-gaps of photonic crystals can be utilized for frequency filtering. In analogy to the chromatic band-gaps and the frequency filtering, the angular band-gaps and the angular (spatial) filtering are also possible in photonic crystals. In this article, we review the recent advances of the spatial filtering using the photonic crystals in different propagation regimes and for different geometries. We review the most evident configuration of filtering in Bragg regime (with the back-reflection—i.e., in the configuration with band-gaps) as well as in Laue regime (with forward deflection—i.e., in the configuration without band-gaps). We explore the spatial filtering in crystals with different symmetries, including axisymmetric crystals; we discuss the role of chirping, i.e., the dependence of the longitudinal period along the structure. We also review the experimental techniques to fabricate the photonic crystals and numerical techniques to explore the spatial filtering. Finally, we discuss several implementations of such filters for intracavity spatial filtering.

  4. Dielectric matrices with air cavities as a waveguide photonic crystal

    NASA Astrophysics Data System (ADS)

    Usanov, D. A.; Skripal', A. V.; Merdanov, M. K.; Gorlitskii, V. O.

    2016-02-01

    Frequency dependences of the transmission coefficient of a microwave photonic crystal that represents a structure containing alternating layers of ceramic material (Al2O3) with a relatively large number of cavities and foam plastic are studied in the presence and absence of distortions of the periodicity of a photonic structure. The frequency dependences of the transmission coefficient can be analyzed using a model of effective medium that makes it possible to consider the interaction of electromagnetic wave and photonic crystal using a transfer matrix of a 1D photonic crystal. The band character of the frequency dependence of the transmission coefficient of the photonic crystal related to the periodicity of the photonic crystal in the transverse plane for the waveguide with a standard cross section is not manifested in a certain range of material permittivities.

  5. Experimental study of photonic crystal triangular lattices

    NASA Astrophysics Data System (ADS)

    Qin, Ruhu; Qin, Bo; Jin, Chongjun

    1999-06-01

    Triangular lattice photonic crystal behaving in the electromagnetic zones constructed from fused silica cylinders in styrofoam is fabricated. The transmission spectra of the photonic crystal with and without defects are measured. On this basis, the defect modes of photonic crystal were studied, and the potential applications of the photonic crystal are discussed.

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

    NASA Astrophysics Data System (ADS)

    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

  7. Manufacturing method of photonic crystal

    SciTech Connect

    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.

  8. Diamond based photonic crystal microcavities.

    PubMed

    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

  9. Tunable one-dimensional photonic crystal slabs

    NASA Astrophysics Data System (ADS)

    Beccherelli, R.; Bellini, B.; Zografopoulos, D.; Kriezis, E.

    2007-05-01

    A 1D photonic crystal slab based on preferential etching of commercially available silicon-on-insulator wafers is presented. Compared to dry etching, anisotropic wet etching is more tolerant to errors as it is self-stopping on crystallographic {111} planes and it produces a more precise geometry with symmetries and homothetic properties, with surface roughness close to 1 nm. The resulting grooves are infiltrated by low viscosity liquid crystal having large positive optical anisotropy. The use of slanted grooves provides advantages: first of all the complete filling of slanted grooves is simplified when compared to vertical walls structures. Furthermore alignment is significantly facilitated. Indeed the liquid crystal molecules tend to align with their long axis along the submicron grooves. Therefore by forcing reorientation out of a rest position, the liquid crystal presents a choice of refractive indices to the propagating optical field. The liquid crystal behavior is simulated by a finite element method, and coupled to a finite difference time domain method. We investigate different photonic crystal configurations. Large tunability of bandgap edge for TE polarization is demonstrated when switching the liquid crystal with an applied voltage. We have also studied the use of the same device geometry as a very compact microfluidic refractometric sensor.

  10. Transient Plasma Photonic Crystals for High-Power Lasers

    NASA Astrophysics Data System (ADS)

    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.

  11. Transient Plasma Photonic Crystals for High-Power Lasers.

    PubMed

    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. PMID:27314721

  12. Photonic crystal scene projector development

    NASA Astrophysics Data System (ADS)

    Wilson, J. A.; Burckel, B.; Caulfield, J.; Cogan, S.; Massie, M.; Lamott, R.; Snyder, D.; Rapp, R.

    2010-04-01

    This paper describes results from the Extremely High Temperature Photonic Crystal System Technology (XTEMPS) program. The XTEMPS program is developing projector technology based on photonic crystals capable of high dynamic range, multispectral emission from SWIR to LWIR, and realistic band widths. These Photonics Crystals (PhC) are fabricated from refractory materials to provide high radiance and long device lifetime. Cyan is teamed with Sandia National Laboratories, to develop photonics crystals designed for realistic scene projection systems and Nova sensors to utilize their advanced Read In Integrated Circuit (RIIC). PhC based emitters show improved in-band output power efficiency when compared to broad band "graybody" emitters due to the absence of out-of-band emission. Less electrical power is required to achieve high operating temperature, and the potential for nonequilibrium pumping exists. Both effects boost effective radiance output. Cyan has demonstrated pixel designs compatible with Nova's medium format RIIC, ensuring high apparent output temperatures, modest drive currents, and low operating voltages of less than five volts. Unit cell pixel structures with high radiative efficiency have been demonstrated, and arrays using PhC optimized for up to four spectral bands have been successfully patterned.

  13. Photonic crystal surface-emitting lasers

    SciTech Connect

    Chua, Song Liang; Lu, Ling; Soljacic, Marin

    2015-06-23

    A photonic-crystal surface-emitting laser (PCSEL) includes a gain medium electromagnetically coupled to a photonic crystal whose energy band structure exhibits a Dirac cone of linear dispersion at the center of the photonic crystal's Brillouin zone. This Dirac cone's vertex is called a Dirac point; because it is at the Brillouin zone center, it is called an accidental Dirac point. Tuning the photonic crystal's band structure (e.g., by changing the photonic crystal's dimensions or refractive index) to exhibit an accidental Dirac point increases the photonic crystal's mode spacing by orders of magnitudes and reduces or eliminates the photonic crystal's distributed in-plane feedback. Thus, the photonic crystal can act as a resonator that supports single-mode output from the PCSEL over a larger area than is possible with conventional PCSELs, which have quadratic band edge dispersion. Because output power generally scales with output area, this increase in output area results in higher possible output powers.

  14. Optical Magnetometer Incorporating Photonic Crystals

    NASA Technical Reports Server (NTRS)

    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.

  15. Topological photonic crystal with ideal Weyl points

    NASA Astrophysics Data System (ADS)

    Wang, Luyang; Jian, Shao-Kai; Yao, Hong

    Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on symmetry analysis, we show that a minimal number of symmetry-related Weyl points can be realized in time-reversal invariant photonic crystals. We propose to realize these ``ideal'' Weyl points in modified double-gyroid photonic crystals, which is confirmed by our first-principle photonic band-structure calculations. Photonic crystals with ideal Weyl points are qualitatively advantageous in applications such as angular and frequency selectivity, broadband invisibility cloaking, and broadband 3D-imaging.

  16. Topological photonic crystal with equifrequency Weyl points

    NASA Astrophysics Data System (ADS)

    Wang, Luyang; Jian, Shao-Kai; Yao, Hong

    2016-06-01

    Weyl points in three-dimensional photonic crystals behave as monopoles of Berry flux in momentum space. Here, based on general symmetry analysis, we show that a minimal number of four symmetry-related (consequently equifrequency) Weyl points can be realized in time-reversal invariant photonic crystals. We further propose an experimentally feasible way to modify double-gyroid photonic crystals to realize four equifrequency Weyl points, which is explicitly confirmed by our first-principle photonic band-structure calculations. Remarkably, photonic crystals with equifrequency Weyl points are qualitatively advantageous in applications including angular selectivity, frequency selectivity, invisibility cloaking, and three-dimensional imaging.

  17. Photonic crystals--a step towards integrated circuits for photonics.

    PubMed

    Thylén, Lars; Qiu, Min; Anand, Srinivasan

    2004-09-20

    The field of photonic crystals has, over the past few years, received dramatically increased attention. Photonic crystals are artificially engineered structures that exhibit a periodic variation in one, two, or three dimensions of the dielectric constant, with a period of the order of the pertinent light wavelength. Such structures in three dimensions should exhibit properties similar to solid-state electronic crystals, such as bandgaps, in other words wavelength regions where light cannot propagate in any direction. By introducing defects into the periodic arrangement, the photonic crystals exhibit properties analogous to those of solid-state crystals. The basic feature of a photonic bandgap was indeed experimentally demonstrated in the beginning of the 1990s, and sparked a large interest in, and in many ways revitalized, photonics research. There are several reasons for this attention. One is that photonic crystals, in their own right, offer a proliferation of challenging research tasks, involving a multitude of disciplines, such as electromagnetic theory, nanofabrication, semi-conductor technology, materials science, biotechnology, to name a few. Another reason is given by the somewhat more down-to-earth expectations that photonics crystals will create unique opportunities for novel devices and applications, and contribute to solving some of the issues that have plagued photonics such as large physical sizes, comparatively low functionality, and high costs. Herein, we will treat some basics of photonic crystal structures and discuss the state-of-the-art in fabrication as well give some examples of devices with unique properties, due to the use of photonic crystals. We will also point out some of the problems that still remain to be solved, and give a view on where photonic crystals currently stand. PMID:15499844

  18. Frozen multipartite entanglement in photonic crystals

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Xu, Jing-Bo

    2016-06-01

    We investigate the multipartite entanglement dynamics of a many-body system consisting of N identical two-level atoms locally embedded in their own band-gap photonic crystals. It is shown that the tripartite entanglement of this photonic-crystal system can be frozen in a stationary state. We also find that a double-sudden-change phenomenon of four-partite entanglement occurs in this photonic-crystal system during the decoherence process under certain suitable conditions.

  19. Monochromatic Wannier Functions in the Theory of 2D Photonic Crystals and Photonic Crystal Fibers

    SciTech Connect

    Mazhirina, Yu. A.; Melnikov, L. A.

    2011-10-03

    The use of the monochromatic Wannier functions which have the temporal dependence as (exp(-i{omega}t)) in the theory of 2D photonic crystals and photonic crystal fibers is proposed. Corresponding equations and formulae are derived and discussed.

  20. Statistics of scattered photons from a driven three-level emitter in 1D open space

    SciTech Connect

    Roy, Dibyendu; Bondyopadhaya, Nilanjan

    2014-01-07

    We derive the statistics of scattered photons from a Λ- or ladder-type three-level emitter (3LE) embedded in a 1D open waveguide. The weak probe photons in the waveguide are coupled to one of the two allowed transitions of the 3LE, and the other transition is driven by a control beam. This system shows electromagnetically induced transparency (EIT) which is accompanied with the Autler-Townes splitting (ATS) at a strong driving by the control beam, and some of these effects have been observed recently. We show that the nature of second-order coherence of the transmitted probe photons near two-photon resonance changes from bunching to antibunching to constant as strength of the control beam is ramped up from zero to a higher value where the ATS appears.

  1. Radial and Azimuthal Polarizer Using a One-Dimensional Photonic Crystal with a Patterned Liquid Crystal Defect Layer

    NASA Astrophysics Data System (ADS)

    Tagashira, Kenji; Yoshida, Hiroyuki; Kubo, Hitoshi; Fujii, Akihiko; Ozaki, Masanori

    2010-06-01

    We propose a radial and azimuthal polarizer (RAP) using a one-dimensional photonic crystal (1D PhC) with a patterned liquid crystal defect layer. A concentrically aligned liquid crystal defect layer in the 1D PhC causes the defect modes to be polarized azimuthally or radially, depending on the wavelength. Switching between these two polarizations is achieved by controlling the incident light wavelength.

  2. Tunable liquid crystal photonic devices

    NASA Astrophysics Data System (ADS)

    Fan, Yun-Hsing

    2005-07-01

    Liquid crystal (LC)-based adaptive optics are important for information processing, optical interconnections, photonics, integrated optics, and optical communications due to their tunable optical properties. In this dissertation, we describe novel liquid crystal photonic devices. In Chap. 3, we demonstrate a novel electrically tunable-efficiency Fresnel lens which is devised for the first time using nanoscale PDLC. The tunable Fresnel lens is very desirable to eliminate the need of external spatial light modulator. The nanoscale LC devices are polarization independent and exhibit a fast response time. Because of the small droplet sizes, the operating voltage is higher than 100 Vrms. To lower the driving voltage, in Chap. 2 and Chap. 3, we have investigated tunable Fresnel lens using polymer-network liquid crystal (PNLC) and phase-separated composite film (PSCOF). The operating voltage is below 12 Vrms. The PNLC and PSCOF devices are polarization dependent. To overcome this shortcoming, stacking two cells with orthogonal alignment directions is a possibility. Using PNLC, we also demonstrated LC blazed grating. The diffraction efficiency of these devices is continuously controlled by the electric field. We also develop a system with continuously tunable focal length. A conventional mechanical zooming system is bulky and power hungry. In Chap. 4, we developed an electrically tunable-focus flat LC spherical lens and microlens array. A huge tunable range from 0.6 m to infinity is achieved by the applied voltage. In Chap. 5, we describe a LC microlens array whose focal length can be switched from positive to negative by the applied voltage. The fast response time feature of our LC microlens array will be very helpful in developing 3-D animated images. In Chap. 6, we demonstrate polymer network liquid crystals for switchable polarizers and optical shutters. The use of dual-frequency liquid crystal and special driving scheme leads to a sub-millisecond response time. In

  3. Energy transduction in surface photonic crystals

    NASA Astrophysics Data System (ADS)

    Yang, Fuchyi

    2011-12-01

    This dissertation is a detailed investigation of the fabrication, design, characterization, and understanding of physical principles of energy transduction in surface photonic crystals which are engineered for various applications. One-dimensional photonic crystals are engineered as optically tunable reflectance filters for lambda = 632.8 nm wavelength light by incorporating azobenzene liquid crystal dye molecules into the photonic crystal structure. Optical energy is transduced to accomplish mechanical work by exciting the dye molecules into different physical configurations, leading to changes in the optical properties of the dye molecules, namely their refractive index. This mechanism is used to tune the reflection resonance of the photonic crystal filter. The spectral and temporal optical tuning response of the photonic crystal filter due to excitation light at lambda = 532 nm is characterized. Modulation of the transmitted and reflected lambda = 632.8 nm light is achieved at microsecond time response. Two-dimensional photonic crystals are also investigated as reflectance filters for lambda = 532 nm wavelength light. Both optically tunable and static reflectance filters are studied. Again, azobenzene liquid crystal molecules are incorporated into the photonic crystal to achieve optical tuning of the reflectance wavelength. In this case, the lambda = 532 nm wavelength light is used for self-modulation. That is, the light serves both to optically tune the photonic crystal filter as well as to modulate its own reflection efficiency through the photonic crystal filter. Moreover, stacking of multiple photonic crystals into a single filter is studied for both static and optically tunable photonic crystal filters. It is shown that this approach improves the performance of the photonic crystal reflectance filter by increasing its optical density and its angular tolerance at the reflection wavelength of lambda = 532 nm. Additionally, surface photonic crystals are

  4. Photonic crystal scintillators and methods of manufacture

    SciTech Connect

    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.

  5. Tunable photonic structures based on silicon and liquid crystals

    NASA Astrophysics Data System (ADS)

    Perova, Tatiana S.; Tolmachev, Vladimir A.; Astrova, Ekaterina V.

    2008-01-01

    This paper is focused on the design, fabrication and characterization of the conventional and tunable photonic devices based on grooved silicon, serving as one-dimensional (1D) photonic crystal. The advantages of these photonic structures are as follows: the large refractive index contrast, in-plane moulding of the light flow, the possibility to fabricate a composite photonic structures by filling the grooves with a different compounds and compatibility with current semiconductor processing techniques. The optical properties of grooved Si structures were simulated using a transfer matrix method and gap map method and have been verified experimentally using FTIR microscopy. The air spaces in the basic silicon-air matrices were infiltrated with nematic liquid crystal E7. It is shown that the optical properties of the obtained composite 1D photonic crystals can be tuned by means of electro- and thermo-optical effects. Such a structures suit well for the various elements of the integrated optics and can serve as a building blocks for optical interconnects.

  6. Public Release of a One Dimensional Version of the Photon Clean Method (PCM1D)

    NASA Astrophysics Data System (ADS)

    Carpenter, Matthew H.; Jernigan, J. G.

    2006-09-01

    We announce the public release of a one dimensional version of the Photon Clean Method (PCM1D). This code is in the general class of "inverse Monte Carlo" methods and is specifically designed to interoperate with the public analysis tools available from the Chandra Science Center and the HEASARC. The tool produces models of event based data on a photon by photon basis. The instrument models are based on the standard ARF and RMF fits files. The resulting models have a high number of degrees of freedom of order the number of photons detected providing an alternative analysis compared to the usual method of fitting models with only a few parameters. The original work on this method is described in ADASS 1996 (Jernigan and Vezie). We thank H. Tananbaum and J. McDowell of the Chandra Science Center, S. Kahn, the RGS/XMM-Newton US team leader, and W. Craig and S. Labov of the I Division of LLNL for their support for the development of the PCM concept. We thank P. Beiersdorfer and the EBIT team for the support to develop the first public version of PCM1D.

  7. Liquid crystal orientation control in photonic liquid crystal fibers

    NASA Astrophysics Data System (ADS)

    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.

  8. Butterfly wing color: A photonic crystal demonstration

    NASA Astrophysics Data System (ADS)

    Proietti Zaccaria, Remo

    2016-01-01

    We have theoretically modeled the optical behavior of a natural occurring photonic crystal, as defined by the geometrical characteristics of the Teinopalpus Imperialis butterfly. In particular, following a genetic algorithm approach, we demonstrate how its wings follow a triclinic crystal geometry with a tetrahedron unit base. By performing both photonic band analysis and transmission/reflection simulations, we are able to explain the characteristic colors emerging by the butterfly wings, thus confirming their crystal form.

  9. Spatial solitons in chi(2) planar photonic crystals.

    PubMed

    Gallo, Katia; Assanto, Gaetano

    2007-11-01

    We analyze light self-confinement induced by multiple nonlinear resonances in a two-dimensional chi(2) photonic crystal. With reference to second-harmonic generation in a hexagonal lattice, we show that the system can not only support two-color (1+1)D solitary waves with enhanced confinement and steering capabilities but also enable novel features such as wavelength-dependent soliton routing. PMID:17975626

  10. Photonic crystal microcavity lasers and laser arrays

    NASA Astrophysics Data System (ADS)

    Cao, Jiang-Rong

    As a state-of-the-art technology, photonic crystal microcavity lasers have great potentials to resolve many semiconductor laser performance challenges, owing to their compact size, high spontaneous emission factor, and inherent advantages in dimension scalability. This thesis describes efficient numerical analyzing methods for multimode photonic crystal microcavities, including a parallel computing three-dimensional finite-difference time-domain method combined with Pade interpolation, point group projection, and vectorial Green's function method. With the help of these analyzing tools, various experimental photonic crystal microcavity devices fabricated in InGaAsP/InP based materials were studies. Room temperature optical pumped InGaAsP suspended membrane photonic crystal microcavity lasers were demonstrated. Their lithographical fine-tuning, above room temperature operations, mode identifications and polarizations were demonstrated. Room temperature continuous wave (CW) optically pumped photonic crystal microcavity lasers at diameter less than 3.2 mum were demonstrated with crystalline alpha-Al 2O3 (sapphire) as a cladding layer to the InGaAsP membrane. The far-field radiation profiles from these microcavity lasers were measured and compared with our numerical modeling predictions. Two electrical injection scenes for photonic crystal microcavity lasers were introduced, together with some preliminary results including the demonstrations of optically pumped lasing of highly doped cavities and cavities with an electrical conduction post underneath. Electrically excited photonic crystal microcavity light emitting diodes (LEDs) were also experimentally demonstrated.

  11. Guided-wave liquid-crystal photonics.

    PubMed

    Zografopoulos, D C; Asquini, R; Kriezis, E E; d'Alessandro, A; Beccherelli, R

    2012-10-01

    In this paper we review the state of the art in the field of liquid-crystal tunable guided-wave photonic devices, a unique type of fill-once, molecular-level actuated, optofluidic systems. These have recently attracted significant research interest as potential candidates for low-cost, highly functional photonic elements. We cover a full range of structures, which span from micromachined liquid-crystal on silicon devices to periodic structures and liquid-crystal infiltrated photonic crystal fibers, with focus on key-applications for photonics. Various approaches on the control of the LC molecular orientation are assessed, including electro-, thermo- and all-optical switching. Special attention is paid to practical issues regarding liquid-crystal infiltration, molecular alignment and actuation, low-power operation, as well as their integrability in chip-scale or fiber-based devices. PMID:22842818

  12. Novel photonic crystal cavities and related structures.

    SciTech Connect

    Luk, Ting Shan

    2007-11-01

    The key accomplishment of this project is to achieve a much more in-depth understanding of the thermal emission physics of metallic photonic crystal through theoretical modeling and experimental measurements. An improved transfer matrix technique was developed to enable incorporation of complex dielectric function. Together with microscopic theory describing emitter radiative and non-radiative relaxation dynamics, a non-equilibrium thermal emission model is developed. Finally, experimental methodology was developed to measure absolute emissivity of photonic crystal at high temperatures with accuracy of +/-2%. Accurate emissivity measurements allow us to validate the procedure to treat the effect of the photonic crystal substrate.

  13. Single-Photon Source for Quantum Information Based on Single Dye Molecule Fluorescence in Liquid Crystal Host

    SciTech Connect

    Lukishova, S.G.; Knox, R.P.; Freivald, P.; McNamara, A.; Boyd, R.W.; Stroud, Jr., C.R.; Schmid, A.W.; Marshall, K.L.

    2006-08-18

    This paper describes a new application for liquid crystals: quantum information technology. A deterministically polarized single-photon source that efficiently produces photons exhibiting antibunching is a pivotal hardware element in absolutely secure quantum communication. Planar-aligned nematic liquid crystal hosts deterministically align the single dye molecules which produce deterministically polarized single (antibunched) photons. In addition, 1-D photonic bandgap cholesteric liquid crystals will increase single-photon source efficiency. The experiments and challenges in the observation of deterministically polarized fluorescence from single dye molecules in planar-aligned glassy nematic-liquid-crystal oligomer as well as photon antibunching in glassy cholesteric oligomer are described for the first time.

  14. Analysis of photon recycling using metallic photonic crystal

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Sung; Lin, Shawn-Yu; Chang, Allan S. P.; Lee, Jae-Hwang; Ho, Kai-Ming

    2007-09-01

    We investigate a photon recycling scheme using two-dimensional metallic photonic crystals made of silver to improve the energy efficiency of an incandescent light source. A theoretical framework is presented to analyze the resultant photon-recycled lighting system. Calculation results show that the system can reach a maximum luminous efficiency of 125 lm/W, which is 8 times higher than that of a bare blackbody radiation at 2800 K. The color temperature of the system is calculated to be around 3500 K or below, while the color rendering index is between 68 and 90. These results suggest that a photon-recycled incandescent light source using metallic photonic crystals can be a viable alternative future lighting solution.

  15. Multifunctional Glassy Liquid Crystal for Photonics

    SciTech Connect

    Chen,S.H.

    2004-11-05

    As an emerging class of photonic materials, morphologically stable glassy liquid crystals, were developed following a versatile molecular design approach. Glassy cholesteric liquid crystals with elevated phase-transition temperatures and capability for selective-wavelength reflection and circular polarization were synthesized via determinstic synthesis strategies. Potential applications of glassy cholesteric liquid crystals include high-performance polarizers, optical notch filters and reflectors, and circularly polarized photoluminescence. A glassy nematic liquid crystal comprising a dithienylethene core was also synthesized for the demonstration of nondestructive rewritable optical memory and photonic switching in the sollid state.

  16. Coupled External Cavity Photonic Crystal Enhanced Fluorescence

    PubMed Central

    Pokhriyal, Anusha; Lu, Meng; Ge, Chun; Cunningham, Brian T.

    2016-01-01

    We report a fundamentally new approach to enhance fluorescence in which surface adsorbed fluorophore-tagged biomolecules are excited on a photonic crystal surface that functions as a narrow bandwidth and tunable mirror of an external cavity laser. This scheme leads to ~10× increase in the electromagnetic enhancement factor compared to ordinary photonic crystal enhanced fluorescence. In our experiments, the cavity automatically tunes its lasing wavelength to the resonance wavelength of the photonic crystal, ensuring optimal on-resonance coupling even in the presence of variable device parameters and variations in the density of surface-adsorbed capture molecules. We achieve ~105× improvement in the limit of detection of a fluorophore-tagged protein compared to its detection on an unpatterned glass substrate. The enhanced fluorescence signal and easy optical alignment make cavity-coupled photonic crystals a viable approach for further reducing detection limits of optically-excited light emitters that are used in biological assays. PMID:23129575

  17. Wafer-scale plasmonic and photonic crystal sensors

    NASA Astrophysics Data System (ADS)

    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.

  18. Photonic crystal: energy-related applications

    SciTech Connect

    Ye, Zhuo; Park, Joong-Mok; Constant, Kristen; Kim, Tae-Geun; Ho, Kai-Ming

    2012-06-08

    We review recent work on photonic-crystal fabrication using soft-lithography techniques. We consider applications of the resulting structures in energy-related areas such as lighting and solar-energy harvesting. In general, our aim is to introduce the reader to the concepts of photonic crystals, describe their history, development, and fabrication techniques and discuss a selection of energy-related applications.

  19. Photonic Crystal Laser-Driven Accelerator Structures

    SciTech Connect

    Cowan, B.; /SLAC

    2005-09-19

    We discuss simulated photonic crystal structure designs for laser-driven particle acceleration, focusing on three-dimensional planar structures based on the so-called ''woodpile'' lattice. We demonstrate guiding of a speed-of-light accelerating mode by a defect in the photonic crystal lattice and discuss the properties of this mode. We also discuss particle beam dynamics in the structure, presenting a novel method for focusing the beam. In addition we describe some potential coupling methods for the structure.

  20. Photonic crystal waveguide created by selective infiltration

    NASA Astrophysics Data System (ADS)

    Casas Bedoya, A.; Domachuk, P.; Grillet, C.; Monat, C.; Mägi, E. C.; Li, E.; Eggleton, B. J.

    2012-06-01

    The marriage of photonics and microfluidics ("optofluidics") uses the inherent mobility of fluids to reversibly tune photonic structures beyond traditional fabrication methods by infiltrating voids in said structures. Photonic crystals (PhCs) strongly control light on the wavelength scale and are well suited to optofluidic tuning because their periodic airhole microstructure is a natural candidate for housing liquids. The infiltration of a single row of holes in the PhC matrix modifies the effective refractive index allowing optical modes to be guided by the PhC bandgap. In this work we present the first experimental demonstration of a reconfigurable single mode W1 photonic crystal defect waveguide created by selective liquid infiltration. We modified a hexagonal silicon planar photonic crystal membrane by selectively filling a single row of air holes with ~300nm resolution, using high refractive index ionic liquid. The modification creates optical confinement in the infiltrated region and allows propagation of a single optical waveguide mode. We describe the challenges arising from the infiltration process and the liquid/solid surface interaction in the photonic crystal. We include a detailed comparison between analytic and numerical modeling and experimental results, and introduce a new approach to create an offset photonic crystal cavity by varying the nature of the selective infiltration process.

  1. Integrated photonic devices using self-assembled and optically defined photonic crystal superstructures

    NASA Astrophysics Data System (ADS)

    Wang, Ying

    Photonic crystals are structures with dielectric constants modulated in one, two, or three dimensions. They are an interesting subject of active research due to their ability to control the flow of light on a very small-length scale. In the research for this thesis, two integrated photonic devices were designed, fabricated and characterized which utilize the special optical properties of photonic crystals. The first device is a photonic crystal-photodiode micro-electro-optic filter, where a vertical self-assembly method was employed to grow a 3D face-centered cubic (FCC) photonic crystal over a working electro-optic device, a photodiode and a photodiode-plus-preamplifier made using conventional CMOS techniques. The objective of this project was to judge the practicality of the process and to observe the effect of the photonic crystal on the spectral response of the photodiode and photodiode-amplifier. Spectral measurements taken using a grating monochrometer confirmed that a stop band exists in the photocurrent response of this integrated photonic device, photonic crystal photodiode filter, at the predicted wavelength of 600 nm. These results were consistent with the simulation results made by using a 1D slab structure model. Although many groups have developed procedures to successfully grow self-assembled photonic crystals on substrates, we believe this is the first application of grown opals over functioning integrated electronics. This work explored the ability to include photonic functionality on the wafer with integrated electronic circuitry, and demonstrated a simple, practical and economic way to achieve it. The second device is a tunable planar waveguide with an optically defined 1D photonic crystal cladding layer. In this section a planar waveguide with a photosensitive cladding layer (mixture of PMMA co DR1 and side-chain nematic liquid crystal polymer) that is optically addressable and reversible is presented. The maximum of intensity decrease of the

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

    SciTech Connect

    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.

  3. Controlling spontaneous emission in bioreplica photonic crystals

    NASA Astrophysics Data System (ADS)

    Jorgensen, Matthew R.; Butler, Elizabeth S.; Bartl, Michael H.

    2012-04-01

    Sophisticated methods have been created by nature to produce structure-based colors as a way to address the need of a wide variety of organisms. This pallet of available structures presents a unique opportunity for the investigation of new photonic crystal designs. Low-temperature sol-gel biotemplating methods were used to transform a single biotemplate into a variety of inorganic oxide structures. The density of optical states was calculated for a diamond-based natural photonic crystal, as well as several structures templated from it. Calculations were experimentally probed by spontaneous emission studies using time correlated single photon counting measurements.

  4. Optical mirage in graded photonic crystals

    NASA Astrophysics Data System (ADS)

    Centeno, Emmanuel; Cassagne, David; Albert, Jean Paul

    2006-04-01

    We present the concept of graded photonic crystals (GPC) and show its ability to enhance the control of light propagation. It is shown that gradual modifications of photonic crystal parameters are able to curve the path of light. This light bending which depends on the wavelength and on the incident angle is examined through parametric studies of the iso-frequency curves. We demonstrate that photonic mirages originate from the same physical principles as the usual atmospheric mirages. Two optical components based on two-dimensional GPCs presenting a super bending effect and a large beam shifting are presented.

  5. Transient dynamic distributed strain sensing using photonic crystal fibres

    NASA Astrophysics Data System (ADS)

    Samad, Shafeek A.; Hegde, G. M.; Roy Mahapatra, D.; Hanagud, S.

    2014-02-01

    A technique to determine the strain field in one-dimensional (1D) photonic crystal (PC) involving high strain rate, high temperature around shock or ballistic impact is proposed. Transient strain sensing is important in aerospace and other structural health monitoring (SHM) applications. We consider a MEMS based smart sensor design with photonic crystal integrated on a silicon substrate for dynamic strain correlation. Deeply etched silicon rib waveguides with distributed Bragg reflectors are suitable candidates for miniaturization of sensing elements, replacing the conventional FBG. Main objective here is to investigate the effect of non-uniform strain localization on the sensor output. Computational analysis is done to determine the static and dynamic strain sensing characteristics of the 1D photonic crystal based sensor. The structure is designed and modeled using Finite Element Method. Dynamic localization of strain field is observed. The distributed strain field is used to calculated the PC waveguide response. The sensitivity of the proposed sensor is estimated to be 0.6 pm/μɛ.

  6. Light-directing chiral liquid crystal nanostructures: from 1D to 3D.

    PubMed

    Bisoyi, Hari Krishna; Li, Quan

    2014-10-21

    Endowing external, remote, and dynamic control to self-organized superstructures with desired functionalities is a principal driving force in the bottom-up nanofabrication of molecular devices. Light-driven chiral molecular switches or motors in liquid crystal (LC) media capable of self-organizing into optically tunable one-dimensional (1D) and three-dimensional (3D) superstructures represent such an elegant system. As a consequence, photoresponsive cholesteric LCs (CLCs), i.e., self-organized 1D helical superstructures, and LC blue phases (BPs), i.e., self-organized 3D periodic cubic lattices, are emerging as a new generation of multifunctional supramolecular 1D and 3D photonic materials in their own right because of their fundamental academic interest and technological significance. These smart stimuli-responsive materials can be facilely fabricated from achiral LC hosts by the addition of a small amount of a light-driven chiral molecular switch or motor. The photoresponsiveness of these materials is a result of both molecular interaction and geometry changes in the chiral molecular switch upon light irradiation. The doped photoresponsive CLCs undergo light-driven pitch modulation and/or helix inversion, which has many applications in color filters, polarizers, all-optical displays, optical lasers, sensors, energy-saving smart devices, and so on. Recently, we have conceptualized and rationally synthesized different light-driven chiral molecular switches that have very high helical twisting powers (HTPs) and exhibit large changes in HTP in different states, thereby enabling wide phototunability of the systems by the addition of very small amounts of the molecular switches into commercially available achiral LCs. The light-driven chiral molecular switches are based on well-recognized azobenzene, dithienylcyclopentene, and spirooxazine derivatives. We have demonstrated high-resolution and lightweight photoaddressable displays without patterned electronics on

  7. Bandgap characteristics of one-dimensional plasma photonic crystal

    SciTech Connect

    Yin Yan; Ma Yanyun; Tian Chenglin; Shao Fuqiu; Xu Han; Zhuo Hongbin; Yu, M. Y.

    2009-10-15

    When two pump laser pulses intersect in an underdense plasma, plasma Bragg grating (PBG) is induced by the slow-varying ponderomotive force [Z. M. Sheng et al., Appl. Phys. B: Lasers Opt. 77, 673 (2003)]. Such a PBG can be considered as a one-dimensional (1D) plasma photonic crystal (PPC). Here the bandgap characteristic of 1D PPC composed of plasma layers of different densities is investigated theoretically and numerically. It is found that when the maximum density is lower than the critical density of the pump laser, there is only one normal-incidence bandgap. When the maximum density is higher than the critical density of the pump laser, high-order bandgaps are found. The theoretical results are verified by 1D particle-in-cell simulations.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Progress in 2D photonic crystal Fano resonance photonics

    NASA Astrophysics Data System (ADS)

    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

  10. Structure, electrochemical properties and capacitance performance of polypyrrole electrodeposited onto 1-D crystals of iridium complex

    NASA Astrophysics Data System (ADS)

    Wysocka-Żołopa, Monika; Winkler, Krzysztof

    2015-12-01

    Composites of polypyrrole and one-dimensional iridium complex crystals [(C2H5)4N]0.55[IrCl2(CO)2] were prepared by in situ two-step electrodeposition. Initially, iridium complex crystals were formed during [IrCl2(CO)2]- complex oxidation. Next, pyrrole was electropolymerized on the surface of the iridium needles. The morphology of the composite was investigated by scanning and transmission electron microscopy. At positive potentials, the iridium complex crystals and the polypyrrole were oxidized. In aprotic solvents, oxidation of the iridium complex crystals resulted in their dissolution. In water containing tetra(n-butyl)ammonium chlorides, the 1-D iridium complex crystals were reversibly oxidized. The product of the iridium complex oxidation remained on the electrode surface in crystalline form. The iridium complex needles significantly influenced the redox properties of the polymer. The polypyrrole involved electrode processes become more reversible in presence of crystals of iridium complex. The current of polypyrrole oxidation was higher compared to that of pure polypyrrole and the capacitance properties of the polymer were significantly enhanced. A specific capacitance as high as 590 F g-1 was obtained for a composite of polypyrrole and 1-D crystals of the iridium complex in water containing tetra(n-butyl)ammonium chloride. This value is approximately twice as high as the capacitance of the pure polymer deposited onto the electrode surface.

  11. Etched distributed Bragg reflectors as three-dimensional photonic crystals: photonic bands and density of states.

    PubMed

    Pavarini, E; Andreani, L C

    2002-09-01

    The photonic band dispersion and density of states (DOS) are calculated for the three-dimensional (3D) hexagonal structure corresponding to a distributed Bragg reflector patterned with a 2D triangular lattice of circular holes. Results for the Si/SiO(2) and GaAs/Al(x)Ga(1-x)As systems determine the optimal parameters for which a gap in the 2D plane occurs and overlaps the 1D gap of the multilayer. The DOS is considerably reduced in correspondence with the overlap of 2D and 1D gaps. Also, the local density of states (i.e., the DOS weighted with the squared electric field at a given point) has strong variations depending on the position. Both results imply substantial changes of spontaneous emission rates and patterns for a local emitter embedded in the structure and make this system attractive for the fabrication of a 3D photonic crystal with controlled radiative properties. PMID:12366275

  12. Liquid crystal devices for photonics applications

    NASA Astrophysics Data System (ADS)

    Chigrinov, Vladimir G.

    2007-11-01

    Liquid crystal (LC) devices for Photonics applications is a hot topic of research. Such elements begin to appear in Photonics market. Passive elements for fiber optical communication systems (DWDM components) based on LC cells can successfully compete with the other elements used for the purpose, such as micro electromechanical (MEM), thermo-optical, opto-mechanical or acousto-optical devices. Application of nematic and ferroelectric LC for high speed communication systems, producing elements that are extremely fast, stable, durable, of low loss, operable over a wide temperature range, and that require small operating voltages and extremely low power consumption. The known LC applications in fiber optics enable to produce switches, filters, attenuators, equalizers, polarization controllers, phase emulators and other fiber optical components. Good robustness due to the absence of moving parts and compatibility with VLSI technology, excellent parameters in a large photonic wavelength range, whereas the complexity of the design and the cost of the device are equivalent to regular passive matrix LC displays makes LC fiber optical devices very attractive for mass production. We have already successfully fabricated certain prototypes of the optical switches based on ferroelectric and nematic LC materials. The electrooptical modes used for the purpose included the light polarization rotation, voltage controllable diffraction and fast switching of the LC refractive index. We used the powerful software to optimize the LC modulation characteristics. Use of photo-alignment technique pioneered by us makes it possible to develop new LC fiber components. Almost all the criteria of perfect LC alignment are met in case of azo-dye layers. We have already used azo-dye materials to align LC in superthin photonic holes, curved and 3D surfaces and as cladding layers in microring silicon based resonators. The prototypes of new LC efficient Photonics devices are envisaged. Controllable

  13. Crystallization, Crystal Orientation and Morphology of Poly(ethylene oxide) under 1D Defect-Free Nanoscale Confinement

    NASA Astrophysics Data System (ADS)

    Hsiao, Ming-Siao; Zheng, Joseph X.; van Horn, Ryan M.; Quirk, Roderic P.; Thomas, Edwin L.; Lotz, Bernard; Cheng, Stephen Z. D.

    2009-03-01

    One-dimensional (1-D) defect-free nanoscale confinement is created by growing single crystals of PS-b-PEO block copolymers in dilute solution. Those defect-free, 1-D confined lamellae having different PEO layer thicknesses in PS-b-PEO lamellar single crystals (or crystal mats) were used to study the polymer recrystallization and crystal orientation evolution as a function of recrystallization temperature (Trx) because the Tg^PS is larger than Tm^PEO in the PS-b-PEO single crystal. The results are summarized as follows. First, by the combination of electron diffraction and known PEO crystallography, the crystallization of PEO only takes place at Trx<-5^oC. Meanwhile a unique tilted PEO orientation is formed at Trx >-5^oC after self-seeding. The origin of the formation of tilted chains in the PEO crystal will be addressed. Second, from the analysis of 2D WAXD patterns of crystal mats, it is shown that the change in PEO c-axis orientation from homogeneous at low Trx to homeotropic at higher Trx transitions sharply, within 1^oC. The mechanism inducing this dramatic change in crystal orientation will be investigated in detail.

  14. Photon Molecules in Atomic Gases Trapped Near Photonic Crystal Waveguides

    NASA Astrophysics Data System (ADS)

    Douglas, James S.; Caneva, Tommaso; Chang, Darrick E.

    2016-07-01

    Realizing systems that support robust, controlled interactions between individual photons is an exciting frontier of nonlinear optics. To this end, one approach that has emerged recently is to leverage atomic interactions to create strong and spatially nonlocal interactions between photons. In particular, effective photonic interactions have been successfully created via interactions between atoms excited to Rydberg levels. Here, we investigate an alternative approach, in which atomic interactions arise via their common coupling to photonic crystal waveguides. This technique takes advantage of the ability to separately tailor the strength and range of interactions via the dispersion engineering of the structure itself, which can lead to qualitatively new types of phenomena. For example, much of the work on photon-photon interactions relies on the linear optical effect of electromagnetically induced transparency, in combination with the use of interactions to shift optical pulses into or out of the associated transparency window. Here, we identify a large new class of "correlated transparency windows," in which photonic states of a certain number and shape selectively propagate through the system. Through this technique, we show that molecular bound states of photon pairs can be created.

  15. Photonic quasi-crystal terahertz lasers

    PubMed Central

    Vitiello, Miriam Serena; Nobile, Michele; Ronzani, Alberto; Tredicucci, Alessandro; Castellano, Fabrizio; Talora, Valerio; Li, Lianhe; Linfield, Edmund H.; Davies, A. Giles

    2014-01-01

    Quasi-crystal structures do not present a full spatial periodicity but are nevertheless constructed starting from deterministic generation rules. When made of different dielectric materials, they often possess fascinating optical properties, which lie between those of periodic photonic crystals and those of a random arrangement of scatterers. Indeed, they can support extended band-like states with pseudogaps in the energy spectrum, but lacking translational invariance, they also intrinsically feature a pattern of ‘defects’, which can give rise to critically localized modes confined in space, similar to Anderson modes in random structures. If used as laser resonators, photonic quasi-crystals open up design possibilities that are simply not possible in a conventional periodic photonic crystal. In this letter, we exploit the concept of a 2D photonic quasi crystal in an electrically injected laser; specifically, we pattern the top surface of a terahertz quantum-cascade laser with a Penrose tiling of pentagonal rotational symmetry, reaching 0.1–0.2% wall-plug efficiencies and 65 mW peak output powers with characteristic surface-emitting conical beam profiles, result of the rich quasi-crystal Fourier spectrum. PMID:25523102

  16. Veselago lens by photonic hyper-crystals

    SciTech Connect

    Huang, Zun Narimanov, Evgenii E.

    2014-07-21

    Based on the recent concept of the photonic hyper-crystal—an artificial optical medium that combines the properties of hyperbolic materials and photonic crystals, we present the imaging system functioning as a Veselago lens. This planar lens shows a nearly constant negative refractive index with substantially reduced image aberrations, and can find potential applications in photolithography and hot-spots detection of silicon-based integrated circuits.

  17. Integrated photonic crystal selective emitter for thermophotovoltaics

    NASA Astrophysics Data System (ADS)

    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.

  18. Ultra compact spectrometer apparatus and method using photonic crystals

    NASA Technical Reports Server (NTRS)

    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.

  19. Optical amplification enhancement in photonic crystals

    SciTech Connect

    Sapienza, R.; Leonetti, M.; Froufe-Perez, L. S.; Galisteo-Lopez, J. F.; Lopez, C.; Conti, C.

    2011-02-15

    Improving and controlling the efficiency of a gain medium is one of the most challenging problems of laser research. By measuring the gain length in an opal-based photonic crystal doped with laser dye, we demonstrate that optical amplification is more than twenty-fold enhanced along the {Gamma}-K symmetry directions of the face-centered-cubic photonic crystal. These results are theoretically explained by directional variations of the density of states, providing a quantitative connection between density of the states and light amplification.

  20. Self-assembled tunable photonic hyper-crystals

    NASA Astrophysics Data System (ADS)

    Smolyaninov, Igor; Smolyaninova, Vera; Yost, Bradley; Lahneman, David; Gresock, Thomas; Narimanov, Evgenii

    2015-03-01

    We demonstrate a novel artificial optical material, the 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. This work was supported in part by NSF Grant DMR-1104676, NSF Center for Photonic and Multiscale Nanomaterials, ARO MURI and Gordon and Berry Moore Foundation.

  1. Magneto-tunable one-dimensional graphene-based photonic crystal

    SciTech Connect

    Jahani, D. Soltani-Vala, A. Barvestani, J.; Hajian, H.

    2014-04-21

    We investigate the effect of a perpendicular static magnetic field on the optical bandgap of a one-dimensional (1D) graphene-dielectric photonic crystal in order to examine the possibility of reaching a rich tunable photonic bandgap. The solution of the wave equation in the presence of the anisotropic Hall situation suggests two decoupled circularly polarized wave each exhibiting different degrees of bandgap tunability. It is also numerically demonstrated that applying different values of field intensity lead to perceptible changes in photonic bandgap of such a structure. Finally, the effect of opening a finite electronic gap in the spectrum of graphene on the optical dispersion solution of such a 1D photonic crystal is reported. It is shown that increasing the value of the electronic gap results in the shrinkage of the associated photonic bandgaps.

  2. Crystal orbital studies on the 1D silic-diyne nanoribbons and nanotubes.

    PubMed

    Zhu, Ying; Bai, Hongcun; Huang, Yuanhe

    2016-02-01

    This work presents crystal orbital studies on novel one-dimensional (1D) nanoscale materials derived from a Si-diyne sheet, based on the density functional theory. The two-dimensional (2D) Si-diyne layer is observed to be carbo-merized silicene, with a similar structure to graphdiyne. The 2D Si-diyne and its 1D ribbons and tubes, of different size and chirality, have been addressed systematically. The low dimensional Si-diyne materials studied exhibit relatively high stability, according to phonon-frequency calculations and molecular dynamics simulations. With comparable diameters, the Si-diyne tubes have lower strain energies than silicene and silicon carbide nanotubes. The Si-diyne layer and its 1D derivatives are all semiconductors, regardless of the size and chirality of the strips and tubes. In addition, the band gaps of the 1D Si-diyne nanoribbons and nanotubes with different chirality, always monotonically decrease as their sizes increases. A quantitative relationship between the band gap and the size of the ribbons and tubes was obtained. The mobility of charge carriers for the 1D Si-diyne structures was also investigated. It was found that both hole and electron mobility of the ribbons and tubes exhibit linear increase with increasing size. The electrons have greater mobility than the holes for each strip and tube. In addition, the mechanical properties of the Si-diyne nanostructures were also investigated by calculation of the Young's modulus and the Poisson's ratio. PMID:26744378

  3. Photon statistics in scintillation crystals

    NASA Astrophysics Data System (ADS)

    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

  4. Self-assembled tunable photonic hyper-crystals.

    PubMed

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

    2014-01-01

    We demonstrate a novel artificial optical material, the "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. PMID:25027947

  5. Visible stealth materials based on photonic crystals

    NASA Astrophysics Data System (ADS)

    Yao, Guozheng; Liu, Ying

    2014-08-01

    Optical thin film can be used for invisible cloak. As a kind of low-dimension photonic crystal, it is a candidate for metamaterial with designed Σ and μ. As a coating, it is convenient to be stacked to mimic continuous changing of electromagnetic media. Anti-reflection film is suitable for matching coating between layers of media.

  6. Fabrication and Analysis of Photonic Crystals

    ERIC Educational Resources Information Center

    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…

  7. Photonic Crystal Sensors Based on Porous Silicon

    PubMed Central

    Pacholski, Claudia

    2013-01-01

    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. PMID:23571671

  8. Tunable defect mode realized by graphene-based photonic crystal

    NASA Astrophysics Data System (ADS)

    Fu, Jiahui; Chen, Wan; Lv, Bo

    2016-04-01

    In this literature, we propose an active terahertz 1D photonic crystal, which consists of silicon layers and air layers. A graphene sheet is embedded at the interface between dielectric and air. Tunable photonic band gap is realized by changing the Fermi level of graphene. Transmission Matrix Method is utilized to explain the influence of the graphene layer. We also demonstrate that a dielectric slab attached with a thin sheet made of single-negative metamaterial acts like a pure dielectric slab with a thinner thickness. A tunable blue shift of the band gap can be realized by simply applying different chemical potentials on the graphene sheet. This feature can be utilized for the design of tunable high-gain antenna array and force generator in terahertz band.

  9. Achieving omnidirectional photonic band gap in sputter deposited TiO2/SiO2 one dimensional photonic crystal

    NASA Astrophysics Data System (ADS)

    Jena, S.; Tokas, R. B.; Sarkar, P.; Haque, S. Maidul; Misal, J. S.; Rao, K. D.; Thakur, S.; Sahoo, N. K.

    2015-06-01

    The multilayer structure of TiO2/SiO2 (11 layers) as one dimensional photonic crystal (1D PC) has been designed and then fabricated by using asymmetric bipolar pulse DC magnetron sputtering technique for omnidirectional photonic band gap. The experimentally measured photonic band gap (PBG) in the visible region is well matched with the theoretically calculated band structure (ω vs. k) diagram. The experimentally measured omnidirectional reflection band of 44 nm over the incident angle range of 0°-70° is found almost matching within the theoretically calculated band.

  10. Study of phase transformation and crystal structure for 1D carbon-modified titania ribbons

    SciTech Connect

    Zhou, Lihui Zhang, Fang; Li, Jinxia

    2014-02-15

    One-dimensional hydrogen titanate ribbons were successfully prepared with hydrothermal reaction in a highly basic solution. A series of one-dimensional carbon-modified TiO{sub 2} ribbons were prepared via calcination of the mixture of hydrogen titanate ribbons and sucrose solution under N{sub 2} flow at different temperatures. The phase transformation process of hydrogen titanate ribbons was investigated by in-situ X-ray diffraction at various temperatures. Besides, one-dimensional carbon-modified TiO{sub 2} ribbons calcined at different temperatures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption isotherms, diffuse reflectance ultraviolet–visible spectroscopy, and so on. Carbon-modified TiO{sub 2} ribbons showed one-dimensional ribbon crystal structure and various crystal phases of TiO{sub 2}. After being modified with carbon, a layer of uniform carbon film was coated on the surface of TiO{sub 2} ribbons, which improved their adsorption capacity for methyl orange as a model organic pollutant. One-dimensional carbon-modified TiO{sub 2} ribbons also exhibited enhanced visible-light absorbance with the increase of calcination temperatures. - Highlights: • The synthesis of 1D carbon-modified TiO{sub 2} ribbons. • The phase transformation of 1D carbon-modified TiO{sub 2} ribbons. • 1D carbon-modified TiO{sub 2} exhibites enhanced visible-light absorbance.

  11. Self-assembled tunable photonic hyper-crystals

    PubMed Central

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

    2014-01-01

    We demonstrate a novel artificial optical material, the “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. PMID:25027947

  12. Review on photonic crystal coatings for scintillators

    NASA Astrophysics Data System (ADS)

    Knapitsch, Arno; Lecoq, Paul

    2014-11-01

    The amount of light and its time distribution are key factors determining the performance of scintillators when used as radiation detectors. However most inorganic scintillators are made of heavy materials and suffer from a high index of refraction which limits light extraction efficiency. This increases the path length of the photons in the material with the consequence of higher absorption and tails in the time distribution of the extracted light. Photonic crystals are a relatively new way of conquering this light extraction problem. Basically they are a way to produce a smooth and controllable index matching between the scintillator and the output medium through the nanostructuration of a thin layer of optically transparent high index material deposited at the coupling face of the scintillator. Our review paper discusses the theory behind this approach as well as the simulation details. Furthermore the different lithography steps of the production of an actual photonic crystal sample will be explained. Measurement results of LSO scintillator pixels covered with a nanolithography machined photonic crystal surface are presented together with practical tips for the further development and improvement of this technique.

  13. The bifoil photodyne: a photonic crystal oscillator.

    PubMed

    Lugo, J E; Doti, R; Sanchez, N; de la Mora, M B; del Rio, J A; Faubert, J

    2014-01-01

    Optical tweezers is an example how to use light to generate a physical force. They have been used to levitate viruses, bacteria, cells, and sub cellular organisms. Nonetheless it would be beneficial to use such force to develop a new kind of applications. However the radiation pressure usually is small to think in moving larger objects. Currently, there is some research investigating novel photonic working principles to generate a higher force. Here, we studied theoretically and experimentally the induction of electromagnetic forces in one-dimensional photonic crystals when light impinges on the off-axis direction. The photonic structure consists of a micro-cavity like structure formed of two one-dimensional photonic crystals made of free-standing porous silicon, separated by a variable air gap and the working wavelength is 633 nm. We show experimental evidence of this force when the photonic structure is capable of making auto-oscillations and forced-oscillations. We measured peak displacements and velocities ranging from 2 up to 35 microns and 0.4 up to 2.1 mm/s with a power of 13 mW. Recent evidence showed that giant resonant light forces could induce average velocity values of 0.45 mm/s in microspheres embedded in water with 43 mW light power. PMID:24423985

  14. The bifoil photodyne: a photonic crystal oscillator

    NASA Astrophysics Data System (ADS)

    Lugo, J. E.; Doti, R.; Sanchez, N.; de La Mora, M. B.; Del Rio, J. A.; Faubert, J.

    2014-01-01

    Optical tweezers is an example how to use light to generate a physical force. They have been used to levitate viruses, bacteria, cells, and sub cellular organisms. Nonetheless it would be beneficial to use such force to develop a new kind of applications. However the radiation pressure usually is small to think in moving larger objects. Currently, there is some research investigating novel photonic working principles to generate a higher force. Here, we studied theoretically and experimentally the induction of electromagnetic forces in one-dimensional photonic crystals when light impinges on the off-axis direction. The photonic structure consists of a micro-cavity like structure formed of two one-dimensional photonic crystals made of free-standing porous silicon, separated by a variable air gap and the working wavelength is 633 nm. We show experimental evidence of this force when the photonic structure is capable of making auto-oscillations and forced-oscillations. We measured peak displacements and velocities ranging from 2 up to 35 microns and 0.4 up to 2.1 mm/s with a power of 13 mW. Recent evidence showed that giant resonant light forces could induce average velocity values of 0.45 mm/s in microspheres embedded in water with 43 mW light power.

  15. The bifoil photodyne: a photonic crystal oscillator

    PubMed Central

    Lugo, J. E.; Doti, R.; Sanchez, N.; de la Mora, M. B.; del Rio, J. A.; Faubert, J.

    2014-01-01

    Optical tweezers is an example how to use light to generate a physical force. They have been used to levitate viruses, bacteria, cells, and sub cellular organisms. Nonetheless it would be beneficial to use such force to develop a new kind of applications. However the radiation pressure usually is small to think in moving larger objects. Currently, there is some research investigating novel photonic working principles to generate a higher force. Here, we studied theoretically and experimentally the induction of electromagnetic forces in one-dimensional photonic crystals when light impinges on the off-axis direction. The photonic structure consists of a micro-cavity like structure formed of two one-dimensional photonic crystals made of free-standing porous silicon, separated by a variable air gap and the working wavelength is 633 nm. We show experimental evidence of this force when the photonic structure is capable of making auto-oscillations and forced-oscillations. We measured peak displacements and velocities ranging from 2 up to 35 microns and 0.4 up to 2.1 mm/s with a power of 13 mW. Recent evidence showed that giant resonant light forces could induce average velocity values of 0.45 mm/s in microspheres embedded in water with 43 mW light power. PMID:24423985

  16. Photonic crystal slab quantum cascade detector

    SciTech Connect

    Reininger, Peter Schwarz, Benedikt; Harrer, Andreas; Zederbauer, Tobias; Detz, Hermann; Maxwell Andrews, Aaron; Gansch, Roman; Schrenk, Werner; Strasser, Gottfried

    2013-12-09

    In this Letter, we demonstrate the design, fabrication, and characterization of a photonic crystal slab quantum cascade detector (PCS-QCD). By employing a specifically designed resonant cavity, the performance of the photodetector is improved in three distinct ways. The PCS makes the QCD sensitive to surface normal incident light. It resonantly enhances the photon lifetime inside the active zone, thus increasing the photocurrent significantly. And, the construction form of the device inherently decreases the noise. Finally, we compare the characteristics of the PCS-QCD to a PCS - quantum well infrared photodetector and outline the advantages for certain fields of applications.

  17. Photonic crystals: Theory and device applications

    NASA Astrophysics Data System (ADS)

    Fan, Shanhui

    In this thesis, first-principle frequency-domain and time-domain methods are developed and applied to investigate various properties and device applications of photonic crystals. In Chapter 2, I discuss the two numerical methods used to investigate the properties of photonic crystals. The first solves Maxwell's equations in the frequency domain, while the second solves the equations in the time domain. The frequency-domain method yields the frequency, polarization, symmetry, and field distribution of every eigenmode of the system; the time-domain method allows one to determine the temporal behavior of the modes. In Chapter 3, a new class of three-dimensional photonic crystal structures is introduced that is amenable for fabrication at submicron-length scales. The structures give rise to a 3D photonic bandgap. They consist of a layered structure in which a series of cylindrical air holes are etched at normal incidence. The calculation demonstrates the existence of a gap as large as 14% of the mid-gap frequency using Si, SiO2, and air; and 23% using Si and air. In Chapter 4, the bandstructure and transmission properties of three-dimensional metallodielectric photonic crystals are presented. The metallodielectric crystals are modeled as perfect electrical conducting objects embedded in dielectric media. We investigate the face-centered-cubic (fcc) lattice, and the diamond lattice. Partial gaps are predicted in the fcc lattice, in excellent agreement with recent experiments. Complete gaps are found in a diamond lattice of isolated metal spheres. The gaps appear between the second and third bands, and their sizes can be larger than 60% when the radius of the spheres exceeds 21% of the cubic unit cell size. In Chapter 5, I investigate the properties of resonant modes which arise from the introduction of local defects in two-dimensional (2D) and 3D photonic crystals. The properties of these modes can be controlled by changing the nature and the size of the defects. The

  18. Crystal orbital studies on the 1D silic-diyne nanoribbons and nanotubes

    NASA Astrophysics Data System (ADS)

    Zhu, Ying; Bai, Hongcun; Huang, Yuanhe

    2016-02-01

    This work presents crystal orbital studies on novel one-dimensional (1D) nanoscale materials derived from a Si-diyne sheet, based on the density functional theory. The two-dimensional (2D) Si-diyne layer is observed to be carbo-merized silicene, with a similar structure to graphdiyne. The 2D Si-diyne and its 1D ribbons and tubes, of different size and chirality, have been addressed systematically. The low dimensional Si-diyne materials studied exhibit relatively high stability, according to phonon-frequency calculations and molecular dynamics simulations. With comparable diameters, the Si-diyne tubes have lower strain energies than silicene and silicon carbide nanotubes. The Si-diyne layer and its 1D derivatives are all semiconductors, regardless of the size and chirality of the strips and tubes. In addition, the band gaps of the 1D Si-diyne nanoribbons and nanotubes with different chirality, always monotonically decrease as their sizes increases. A quantitative relationship between the band gap and the size of the ribbons and tubes was obtained. The mobility of charge carriers for the 1D Si-diyne structures was also investigated. It was found that both hole and electron mobility of the ribbons and tubes exhibit linear increase with increasing size. The electrons have greater mobility than the holes for each strip and tube. In addition, the mechanical properties of the Si-diyne nanostructures were also investigated by calculation of the Young’s modulus and the Poisson’s ratio.

  19. Strain control of one-dimensional graphene-based photonic crystal

    NASA Astrophysics Data System (ADS)

    Jahani, Dariush; Soltani-Vala, Ali; Barvestani, Jamal

    2016-05-01

    Motivated by resent experimental realization of a 1D strain-tunable photonic crystals and also increasing successes in strain-engineering in grapehene, we demonstrate the capability of a controllable photonic bandgap of a 1D graphene-dielectric photonic crystal by uniaxial strained graphene exhibiting either shrinkage or broadening along different chain crystalline orientations. Moreover, more analyzing over an electric field deviation angle to the stretching direction shows that the photonic spectrums are more sensitive to stronger deformations. Finally, we address how some resulting locked-up situations provide the measurement of the strain dependence of the chemical potential which is of considerable concern to be detectable as well as different strain states.

  20. Photonic crystal slab waveguides in moderate index contrast media: Generalized transverse Bragg waveguides

    NASA Astrophysics Data System (ADS)

    Burckel, David Bruce

    wavelength to period ratio. These optical results indicated a need for a deeper understanding of the confinement/guiding mechanisms in such waveguide structures. A simplification of the full 2-D problem to a more tractable "tilted 1-D" geometry led to the proposal of a new waveguide geometry, Generalized Transverse Bragg Waveguides (GTBW), as well as a new propagation mode characterized by spatial variation in both the transverse direction as well as the direction of propagation. GTBW demonstrate many of the same dispersion tunability traits exhibited in complete bandgap photonic crystal waveguides, under more modest fabrication demands, and moreover provide much insight into photonic crystal waveguide modes of all types. Generalized Transverse Bragg Waveguides are presented in terms of the standard physical properties associated with waveguides, including the dispersion relation, expressions for the spatial field profile, and the concepts of phase and group velocity. In addition, the proposal of at least one obvious application, semiconductor optical amplifiers, is offered.

  1. Breakdown of Bose-Einstein Distribution in Photonic Crystals

    PubMed Central

    Lo, Ping-Yuan; Xiong, Heng-Na; Zhang, Wei-Min

    2015-01-01

    In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced localized long-lived photon dynamics, we discover that cavity photons in photonic crystals do not obey Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine the long-lived non-Markovain dynamics with thermal fluctuations together to form photon states that memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger or much larger than the cavity detuning energy. In this investigation, a crossover phenomenon from equilibrium to nonequilibrium steady states is also revealed. PMID:25822135

  2. A plasma photonic crystal bandgap device

    NASA Astrophysics Data System (ADS)

    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.

  3. Focusing concave lens using photonic crystals with magnetic materials.

    PubMed

    Yang, Shieh-Yueh; Hong, Chin-Yih; Yang, Hong-Chang

    2006-04-01

    The guided modes lying in the upper gap-edge band in the photonic band structure of photonic crystals have negative values of refractive index. This feature generates many interesting optical phenomena, and some spectacular photonic devices such as focusing slabs have been developed. We report the design of a photonic-crystal, planoconcave lens for focusing incident parallel light, and theoretically analyze the chromatic aberrations for TM and TE modes. In addition to dielectric photonic crystals, the chromatic aberration of a magnetic photonic-crystal planoconcave lens was investigated because the magnetic permeability may also contribute to the periodic index contrast in photonic crystals, especially at long wavelengths. A significant difference was found in the chromatic aberration for a TM mode propagating in a dielectric than in a magnetic photonic-crystal planoconcave lens. PMID:16604781

  4. A tunable microwave plasma photonic crystal filter

    NASA Astrophysics Data System (ADS)

    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.

  5. "Wandering" soliton in a nonlinear photonic crystal

    NASA Astrophysics Data System (ADS)

    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.

  6. Absorption enhancement in graphene photonic crystal structures.

    PubMed

    Khaleque, Abdul; Hattori, Haroldo T

    2016-04-10

    Graphene, a single layer of carbon atoms arranged in a honeycomb lattice, is attracting significant interest because of its potential applications in electronic and optoelectronic devices. Although graphene exhibits almost uniform absorption within a large wavelength range, its interaction with light is weak. In this paper, the enhancement of the optical absorption in graphene photonic crystal structures is studied: the structure is modified by introducing scatterers and mirrors. It is shown that the absorption of the graphene photonic crystal structure can be enhanced about four times (nearly 40%) with respect to initial reference absorption of 9.8%. The study can be a useful tool for investigating graphene physics in different optical settings. PMID:27139857

  7. A tunable microwave plasma photonic crystal filter

    SciTech Connect

    Wang, B.; Cappelli, M. A.

    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.

  8. Transmission character of general function photonic crystals

    NASA Astrophysics Data System (ADS)

    Wu, Xiang-Yao; Zhang, Bo-Jun; Yang, Jing-Hai; Zhang, Si-Qi; Liu, Xiao-Jing; Wang, Jing; Ba, Nuo; Hua, Zhong; Yin, Xin-Guo

    2012-08-01

    In the paper, we present a new general function photonic crystals (GFPCs), whose refractive index of medium is a arbitrary function of space position. Unlike conventional photonic crystals (PCs), whose structure grows from two mediums A and B, with different constant refractive indexes na and nb. Based on the Fermat principle, we give the motion equations of light in one-dimensional GFPCs, and calculate its transfer matrix, which is different from the conventional PCs. We choose the linearity refractive index function for two mediums A and B, and find the transmissivity of one-dimensional GFPCs can be much larger or smaller than 1 for different slope linearity refractive index functions, which are different from the transmissivity of conventional PCs (its transmissivity is in the range of 0 and 1). Otherwise, we study the effect of different incident angles, the number of periods and optical thickness on the transmissivity, and obtain some new results different from the conventional PCs.

  9. Metallic photonic crystals at optical wavelengths

    NASA Astrophysics Data System (ADS)

    El-Kady, I.; Sigalas, M. M.; Biswas, R.; Ho, K. M.; Soukoulis, C. M.

    2000-12-01

    We theoretically study three-dimensional metallic photonic-band-gap (PBG) materials at near-infrared and optical wavelengths. Our main objective is to find the importance of absorption in the metal and the suitability of observing photonic band gaps in this structure. For that reason, we study simple cubic structures and the metallic scatterers are either cubes or interconnected metallic rods. Several different metals have been studied (aluminum, gold, copper, and silver). Copper gives the smallest absorption and aluminum is more absorptive. The isolated metallic cubes are less lossy than the connected rod structures. The calculations suggest that isolated copper scatterers are very attractive candidates for the fabrication of photonic crystals at the optical wavelengths.

  10. Nonreciprocal photonic crystal add-drop filter

    SciTech Connect

    Tao, Keyu; Xiao, Jun-Jun; Yin, Xiaobo

    2014-11-24

    We present a versatile add-drop integrated photonic filter (ADF) consisting of nonreciprocal waveguides in which the propagation of light is restricted in one predetermined direction. With the bus and add/drop waveguides symmetrically coupled through a cavity, the four-port device allows each individual port to add and/or drop a signal of the same frequency. The scheme is general and we demonstrate the nonreciprocal ADF with magneto-optical photonic crystals. The filter is immune to waveguide defects, allowing straightforward implementation of multi-channel ADFs by cascading the four-port designs. The results should find applications in wavelength-division multiplexing and related integrated photonic techniques.

  11. Photonic crystal fibres in biomedical investigations

    SciTech Connect

    Skibina, Yu S; Tuchin, Valerii V; Beloglazov, V I; Shteinmaeer, G; Betge, I L; Wedell, R; Langhoff, N

    2011-04-30

    The state of the art in the field of design and study of photonic crystal fibres for biomedical applications is considered and some original results recently obtained by the authors are presented. Optical properties of the fibres that offer prospects of their wide application as biological sensors, 'labs-on-a-chip', and facilities of electromagnetic radiation control in a wide range of wavelengths aimed at designing novel biomedical instrumentation are considered (optical technologies in biophysics and medicine)

  12. Optical microfiber-based photonic crystal cavity

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Sun, Yi-zhi; Andrews, Steve; Li, Zhi-yuan; Ding, Wei

    2016-01-01

    Using a focused ion beam milling technique, we fabricate broad stop band (∼10% wide) photonic crystal (PhC) cavities in adiabatically-tapered silica fibers. Abrupt structural design of PhC mirrors efficiently reduces radiation loss, increasing the cavity finesse to ∼7.5. Further experiments and simulations verify that the remaining loss is mainly due to Ga ion implantation. Such a microfiber PhC cavity probably has potentials in many light-matter interaction applications.

  13. Two-dimensional plasma photonic crystals in dielectric barrier discharge

    SciTech Connect

    Fan Weili; Dong Lifang; Zhang Xinchun

    2010-11-15

    A series of two-dimensional plasma photonic crystals have been obtained by filaments' self-organization in atmospheric dielectric barrier discharge with two water electrodes, which undergo the transition from square to square superlattice and finally to the hexagon. The spatio-temporal behaviors of the plasma photonic crystals in nanosecond scale have been studied by optical method, which show that the plasma photonic crystal is actually an integration of different transient sublattices. The photonic band diagrams of the transverse electric (TE) mode and transverse magnetic mode for each sublattice of these plasma photonic crystals have been investigated theoretically. A wide complete band gap is formed in the hexagonal plasma photonic crystal with the TE mode. The changes of the band edge frequencies and the band gap widths in the evolvement of different structures are studied. A kind of tunable plasma photonic crystal which can be controlled both in space and time is suggested.

  14. Switchable tunneling mode for cylindrical photonic quantum well consisting of photonic crystals containing liquid crystal

    NASA Astrophysics Data System (ADS)

    Hu, C. A.; Yang, S. L.; Yang, T. J.

    2013-06-01

    We propose a cylindrical photonic quantum well made of photonic crystals containing liquid crystals, the properties of which are theoretically calculated and investigated by the transfer matrix method in the cylindrical symmetry system. Liquid crystals are introduced into the photonic quantum well structure as tunable defect layers. When the liquid crystals are pseudo-isotropic state and the azimuthal mode order of incident waves are m=0, there were two pass-bands around certain wavelength. When the liquid crystals are homeotropic state, the reflectance of pass-band at shorter wavelength decreases from 0.75 to 0.05 in the TM mode, but the reflectance does not change in the TE mode. When mode order m=1 and the liquid crystals are pseudo-isotropic state, the reflectance of defect mode stayed the same as m=0. However, the result is reversed while the phase of liquid crystals change from pseudo-isotropic to homeotropic state. The reflectance is the same as in the TM mode, but that in the TE mode decreases substantially from 0.75 to 0.05. The application of our structure to switching device is highly potential.

  15. THz quantum cascade lasers operating on the radiative modes of a 2D photonic crystal.

    PubMed

    Halioua, Y; Xu, G; Moumdji, S; Li, L H; Davies, A G; Linfield, E H; Colombelli, R

    2014-07-01

    Photonic-crystal lasers operating on Γ-point band-edge states of a photonic structure naturally exploit the so-called "nonradiative" modes. As the surface output coupling efficiency of these modes is low, they have relatively high Q factors, which favor lasing. We propose a new 2D photonic-crystal design that is capable of reversing this mode competition and achieving lasing on the radiative modes instead. Previously, this has only been shown in 1D structures, where the central idea is to introduce anisotropy into the system, both at unit-cell and resonator scales. By applying this concept to 2D photonic-crystal patterned terahertz frequency quantum cascade lasers, surface-emitting devices with diffraction-limited beams are demonstrated, with 17 mW peak output power. PMID:24978782

  16. Radiative energy transfer in disordered photonic crystals.

    PubMed

    Erementchouk, M V; Deych, L I; Noh, H; Cao, H; Lisyansky, A A

    2009-04-29

    The difficulty of description of the radiative transfer in disordered photonic crystals arises from the necessity to consider on an equal footing the wave scattering by periodic modulations of the dielectric function and by its random inhomogeneities. We resolve this difficulty by approaching this problem from the standpoint of the general multiple scattering theory in media with an arbitrary regular profile of the dielectric function. We use the general asymptotic solution of the Bethe-Salpeter equation in order to show that for a sufficiently weak disorder the diffusion limit in disordered photonic crystals is presented by incoherent superpositions of the modes of the ideal structure with weights inversely proportional to the respective group velocities. The radiative transfer and the diffusion equations are derived as a relaxation of long scale deviations from this limiting distribution. In particular, it is shown that in general the diffusion is anisotropic unless the crystal has sufficiently rich symmetry, say, the square lattice in 2D or the cubic lattice in 3D. In this case, the diffusion is isotropic and only in this case can the effect of the disorder be characterized by a single mean free path depending on frequency. PMID:21825416

  17. Raman cooling in silicon photonic crystals

    NASA Astrophysics Data System (ADS)

    Chen, Yin-Chung; Bahl, Gaurav

    2016-03-01

    Laser cooling of solids can be achieved through various photon up-conversion processes including anti-Stokes photoluminescence and anti-Stokes light scattering. While it has been shown that cooling using photoluminescence-based methods can achieve efficiency comparable to that of thermoelectric cooling, the reliance on specific transitions of the rare-earth dopants limits material choice. Light scattering, on the other hand, occurs in all materials, and has the potential to enable cooling in most materials. We show that by engineering the photonic density of states of a material, one can suppress the Stokes process, and enhance the anti-Stokes radiation. We employ the well-known diamond-structured photonic crystal patterned in crystalline silicon to demonstrate theoretically that when operating within a high transparency regime, the net energy removal rate from phonon annihilation can overcome the optical absorption. The engineered photonic density of states can thus enable simultaneous cooling of all Raman-active phonon modes and the net cooling of the solid.

  18. Slab photonic crystals with dimer colloid bases

    SciTech Connect

    Riley, Erin K.; Liddell Watson, Chekesha M.

    2014-06-14

    The photonic band gap properties for centered rectangular monolayers of asymmetric dimers are reported. Colloids in suspension have been organized into the phase under confinement. The theoretical model is inspired by the range of asymmetric dimers synthesized via seeded emulsion polymerization and explores, in particular, the band structures as a function of degree of lobe symmetry and degree of lobe fusion. These parameters are varied incrementally from spheres to lobe-tangent dimers over morphologies yielding physically realizable particles. The work addresses the relative scarcity of theoretical studies on photonic crystal slabs with vertical variation that is consistent with colloidal self-assembly. Odd, even and polarization independent gaps in the guided modes are determined for direct slab structures. A wide range of lobe symmetry and degree of lobe fusion combinations having Brillouin zones with moderate to high isotropy support gaps between odd mode band indices 3-4 and even mode band indices 1-2 and 2-3.

  19. Photonic crystal devices formed by a charged-particle beam

    DOEpatents

    Lin, Shawn-Yu; Koops, Hans W. P.

    2000-01-01

    A photonic crystal device and method. The photonic crystal device comprises a substrate with at least one photonic crystal formed thereon by a charged-particle beam deposition method. Each photonic crystal comprises a plurality of spaced elements having a composition different from the substrate, and may further include one or more impurity elements substituted for spaced elements. Embodiments of the present invention may be provided as electromagnetic wave filters, polarizers, resonators, sources, mirrors, beam directors and antennas for use at wavelengths in the range from about 0.2 to 200 microns or longer. Additionally, photonic crystal devices may be provided with one or more electromagnetic waveguides adjacent to a photonic crystal for forming integrated electromagnetic circuits for use at optical, infrared, or millimeter-wave frequencies.

  20. Macroscopic response in active nonlinear photonic crystals.

    PubMed

    Alagappan, Gandhi; John, Sajeev; Li, Er Ping

    2013-09-15

    We derive macroscopic equations of motion for the slowly varying electric field amplitude in three-dimensional active nonlinear optical nanostructures. We show that the microscopic Maxwell equations and polarization dynamics can be simplified to a macroscopic one-dimensional problem in the direction of group velocity. For a three-level active material, we derive the steady-state equations for normal mode frequency, threshold pumping, nonlinear Bloch mode amplitude, and lasing in photonic crystals. Our analytical results accurately recapture the results of exact numerical methods. PMID:24104802

  1. Integrated polarizers based on tapered highly birefringent photonic crystal fibers.

    PubMed

    Romagnoli, Priscila; Biazoli, Claudecir R; Franco, Marcos A R; Cordeiro, Cristiano M B; de Matos, Christiano J S

    2014-07-28

    This paper proposes and demonstrates the creation of sections with a high polarization dependent loss (PDL) in a commercial highly birefringent (polarization maintaining) photonic crystal fiber (PCF), via tapering with pressure applied to the holes. The tapers had a 1-cm-long uniform section with a 66% scale reduction, in which the original microstructure aspect ratio was kept by the pressure application. The resulting waveguides show polarizing action across the entire tested wavelength range, 1510-1600 nm, with a peak PDL of 35.3 dB/cm (c.f. ~1 dB/cm for a typical commercial polarizing fiber). The resulting structure, as well as its production, is extremely simple, and enable a small section with a high PDL to be obtained in a polarization maintaining PCF, meaning that the polarization axes in the polarizing and polarization maintaining sections are automatically aligned. PMID:25089397

  2. Trapped Atoms in One-Dimensional Photonic Crystals

    NASA Astrophysics Data System (ADS)

    Kimble, H.

    2013-05-01

    I describe one-dimensional photonic crystals that support a guided mode suitable for atom trapping within a unit cell, as well as a second probe mode with strong atom-photon interactions. A new hybrid trap is analyzed that combines optical and Casimir-Polder forces to form stable traps for neutral atoms in dielectric nanostructures. By suitable design of the band structure, the atomic spontaneous emission rate into the probe mode can exceed the rate into all other modes by more than tenfold. The unprecedented single-atom reflectivity r0 ~= 0 . 9 for the guided probe field could create new scientific opportunities, including quantum many-body physics for 1 D atom chains with photon-mediated interactions and high-precision studies of vacuum forces. Towards these goals, my colleagues and I are pursuing numerical simulation, device fabrication, and cold-atom experiments with nanoscopic structures. Funding is provided by by the IQIM, an NSF PFC with support of the Moore Foundation, by the AFOSR QuMPASS MURI, by the DoD NSSEFF program (HJK), and by NSF Grant PHY0652914 (HJK). DEC acknowledges funding from Fundacio Privada Cellex Barcelona.

  3. Broadband photon-photon interactions mediated by cold atoms in a photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Litinskaya, Marina; Tignone, Edoardo; Pupillo, Guido

    2016-05-01

    We demonstrate theoretically that photon-photon attraction can be engineered in the continuum of scattering states for pairs of photons propagating in a hollow-core photonic crystal fiber filled with cold atoms. The atoms are regularly spaced in an optical lattice configuration and the photons are resonantly tuned to an internal atomic transition. We show that the hard-core repulsion resulting from saturation of the atomic transitions induces bunching in the photonic component of the collective atom-photon modes (polaritons). Bunching is obtained in a frequency range as large as tens of GHz, and can be controlled by the inter-atomic separation. We provide a fully analytical explanation for this phenomenon by proving that correlations result from a mismatch of the quantization volumes for atomic excitations and photons in the continuum. Even stronger correlations can be observed for in-gap two-polariton bound states. Our theoretical results use parameters relevant for current experiments and suggest a simple and feasible way to induce interactions between photons.

  4. Broadband photon-photon interactions mediated by cold atoms in a photonic crystal fiber

    PubMed Central

    Litinskaya, Marina; Tignone, Edoardo; Pupillo, Guido

    2016-01-01

    We demonstrate theoretically that photon-photon attraction can be engineered in the continuum of scattering states for pairs of photons propagating in a hollow-core photonic crystal fiber filled with cold atoms. The atoms are regularly spaced in an optical lattice configuration and the photons are resonantly tuned to an internal atomic transition. We show that the hard-core repulsion resulting from saturation of the atomic transitions induces bunching in the photonic component of the collective atom-photon modes (polaritons). Bunching is obtained in a frequency range as large as tens of GHz, and can be controlled by the inter-atomic separation. We provide a fully analytical explanation for this phenomenon by proving that correlations result from a mismatch of the quantization volumes for atomic excitations and photons in the continuum. Even stronger correlations can be observed for in-gap two-polariton bound states. Our theoretical results use parameters relevant for current experiments and suggest a simple and feasible way to induce interactions between photons. PMID:27170160

  5. Broadband photon-photon interactions mediated by cold atoms in a photonic crystal fiber.

    PubMed

    Litinskaya, Marina; Tignone, Edoardo; Pupillo, Guido

    2016-01-01

    We demonstrate theoretically that photon-photon attraction can be engineered in the continuum of scattering states for pairs of photons propagating in a hollow-core photonic crystal fiber filled with cold atoms. The atoms are regularly spaced in an optical lattice configuration and the photons are resonantly tuned to an internal atomic transition. We show that the hard-core repulsion resulting from saturation of the atomic transitions induces bunching in the photonic component of the collective atom-photon modes (polaritons). Bunching is obtained in a frequency range as large as tens of GHz, and can be controlled by the inter-atomic separation. We provide a fully analytical explanation for this phenomenon by proving that correlations result from a mismatch of the quantization volumes for atomic excitations and photons in the continuum. Even stronger correlations can be observed for in-gap two-polariton bound states. Our theoretical results use parameters relevant for current experiments and suggest a simple and feasible way to induce interactions between photons. PMID:27170160

  6. Bistability and Stationary Gap Solitons in Quasiperiodic Photonic Crystals Based on Thue-Morse Sequence

    NASA Astrophysics Data System (ADS)

    Grigoriev, Victor; Biancalana, Fabio

    2009-10-01

    The nonlinear properties of quasiperiodic photonic crystals based on Thue-Morse sequence are investigated. The intrinsic asymmetry of these 1D structures for odd generation numbers results in bistability thresholds which are sensitive to propagation direction. Along with resonances of perfect transmission, this feature allows to obtain strongly nonreciprocal propagation and to create an all-optical diode (AOD). The efficiency of two schemes is compared: passive and active when an additional short-term pump signal is applied. The existence of stationary gap solitons for quasiperiodic photonic crystals is shown numerically, and their difference from the Bragg case is emphasized.

  7. Bistability and Stationary Gap Solitons in Quasiperiodic Photonic Crystals Based on Thue-Morse Sequence

    SciTech Connect

    Grigoriev, Victor; Biancalana, Fabio

    2009-10-07

    The nonlinear properties of quasiperiodic photonic crystals based on Thue-Morse sequence are investigated. The intrinsic asymmetry of these 1D structures for odd generation numbers results in bistability thresholds which are sensitive to propagation direction. Along with resonances of perfect transmission, this feature allows to obtain strongly nonreciprocal propagation and to create an all-optical diode (AOD). The efficiency of two schemes is compared: passive and active when an additional short-term pump signal is applied. The existence of stationary gap solitons for quasiperiodic photonic crystals is shown numerically, and their difference from the Bragg case is emphasized.

  8. Young's double-slit experiment in photonic crystals

    SciTech Connect

    Zhang, Lei; Koschny, Thomas; Soukoulis, Costas M.

    2012-10-01

    We present an experimental and numerical study of the transmission of a photonic crystal perforated by two sub-wavelength slits, separated by two wavelengths.The experimental near-field image of the double-slit design of the photonic crystal shows an interference pattern, which is analogous to Young’s experiment. This interference arises as a consequence of the excitation of surface states of the photonic crystals and agrees very well with the simulations.

  9. Back focal plane imaging spectroscopy of photonic crystals

    NASA Astrophysics Data System (ADS)

    Wagner, Rebecca; Heerklotz, Lars; Kortenbruck, Nikolai; Cichos, Frank

    2012-08-01

    Back focal plane imaging spectroscopy is introduced to record angle resolved emission spectra of 3-dimensional colloidal photonic crystals. The auto-fluorescence of the colloids is used to quickly map the photonic band structure up to 72 % of the solid angle of a semisphere with the help of a high numerical aperture objective. Local excitation provides spatially resolved information on the photonic crystal's optical properties. The obtained fractional density of states allows direct conclusions on the crystal's stacking faults or defects.

  10. Biomimetic Photonic Crystals based on Diatom Algae Frustules

    NASA Astrophysics Data System (ADS)

    Mishler, Jonathan; Alverson, Andrew; Herzog, Joseph

    2015-03-01

    Diatom algae are unicellular, photosynthetic microorganisms with a unique external shell known as a frustule. Frustules, which are composed of amorphous silica, exhibit a unique periodic nano-patterning, distinguishing diatoms from other types of phytoplankton. Diatoms have been studied for their distinctive optical properties due to their resemblance of photonic crystals. In this regard, diatoms are not only considered for their applications as photonic crystals, but also for their use as biomimetic templates for artificially fabricated photonic crystals. Through the examination and measurement of the physical characteristics of many scanning electron microscope (SEM) images of diatom frustules, a biomimetic photonic crystal derived from diatom frustules can be recreated and modeled with the finite element method. In this approach, the average geometries of the diatom frustules are used to recreate a 2-dimensional photonic crystal, after which the electric field distribution and optical transmission through the photonic crystal are both measured. The optical transmission is then compared to the transmission spectra of a regular hexagonal photonic crystal, revealing the effects of diatom geometry on their optical properties. Finally, the dimensions of the photonic crystal are parametrically swept, allowing for further control over the transmission of light through the photonic crystal.

  11. Engineering and characterizing light-matter interactions in photonic crystals

    NASA Astrophysics Data System (ADS)

    Brzezinski, Andrew

    Photonic crystals can affect the behavior of visible light, and other electromagnetic waves, in ways that are not possible by other means. The propagation of photons can be completely forbidden or the light can be made to follow a well-defined path. Fluorescent emission can be enhanced for some wavelengths or completely shut off for others, and it is possible to do all this simultaneously in a single structure. However, photonic crystals are very difficult to fabricate as they require precision patterning at sub-micron length scales. This fabrication difficulty has resulted in many of the potential applications for photonic crystals to currently be unrealized. Similarly, there is an abundance of opportunities to explore the workings of photonic crystals and also to develop exciting new methods for their fabrication. The content of this dissertation explores some methods for fabricating photonic crystals, including direct laser writing, interference lithography, colloidal deposition, and chemical vapor deposition. The angle-resolved characterization of photonic crystals is performed on fluorescent photonic crystals that exhibit uniquely photonic effects, which are explained with a simplified model of the electromagnetic wave-functions. Another model is shown to well-explain the emission from fluorescent photonic crystals that are not of sufficient quality to exhibit truly photonic effects. The ability to perform angle-resolved optical characterization is improved with a commercial 4-circle diffractometer. A method to determination the resulting structure of conformal deposition processes proves useful as a tool for the design, modeling, and characterization of photonic crystals. Finally, attempts are made to radically alter the emission of light from rare earth emitters embedded inside photonic crystals.

  12. Negative Refraction experiments in Photonic Crystal prisms

    NASA Astrophysics Data System (ADS)

    Vodo, Plarenta; Parimi, Patanjali. V.; Lu, Wentao. T.; di Gennaro, Emiliano; Sridhar, Srinivas

    2004-03-01

    We have experimentally demonstrated negative refraction in metallic photonic crystal (PC) prisms [1]. The refracted fields in the parallel plate waveguide (PPW) are measured by an automated dipole antenna, which scans the desired area, while the free space (FS) measurements, performed in a anechoic chamber, are measured by a rectangular X-band horn that swings in an arc in far field area. Both TE and TM excitation modes are used in FS experiments. Numerical calculations of the band structure and equi-frequency surface simulations are used to determine frequency regions of negative refraction of the triangular lattice PC. Angle of refraction determined by theoretical simulations and experimental results, are in exceptional good agreement, yielding the negative refraction index. FS and PPW refraction experimental results agree remarkably with simulations. 1. "Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals", P.V Parimi, W.T Lu, P.Vodo J. Sokoloff and S.Sridhar, cond-mat/0306109 (2003)

  13. Multicriteria classification for photonic crystal fiber design

    NASA Astrophysics Data System (ADS)

    Sassi, Imene; Belacel, Nabil; Bouslimani, Yassine; Hamam, Habib; Attia, Rabah

    2008-06-01

    The photonic crystal fibers (PCF) are considered as the future information support for the telecommunication system. In this paper, a multicriteria method is used for the design of the PCFs with the user-defined optical proprieties. This method combines the deductive and the inductive learning and it is introduced for the first time in the field of optical fibers. These simulation tools will be optimized for PCF structures in order to optimize the parameters necessary for the improvement of the communication system performances. The multicriteria decision analysis makes it possible to evaluate the optical proprieties of PCFs by determining the effects of attenuation and distortion caused by Physics Phenomena. This decision is done by the means of a relational model preferably. As a result, this method avoids the recourse to distances and makes it possible to use quantitative and/or qualitative criteria. Moreover, it defeat some difficulties encountered when data are expressed in different units. These advantages allow the new multicriteria classification method to be employed easily to the diagnosis and to the design of photonic-crystals fibers.

  14. Photonic Crystal Laser-Driven Accelerator Structures

    SciTech Connect

    Cowan, Benjamin M.

    2007-08-22

    Laser-driven acceleration holds great promise for significantly improving accelerating gradient. However, scaling the conventional process of structure-based acceleration in vacuum down to optical wavelengths requires a substantially different kind of structure. We require an optical waveguide that (1) is constructed out of dielectric materials, (2) has transverse size on the order of a wavelength, and (3) supports a mode with speed-of-light phase velocity in vacuum. Photonic crystals---structures whose electromagnetic properties are spatially periodic---can meet these requirements. We discuss simulated photonic crystal accelerator structures and describe their properties. We begin with a class of two-dimensional structures which serves to illustrate the design considerations and trade-offs involved. We then present a three-dimensional structure, and describe its performance in terms of accelerating gradient and efficiency. We discuss particle beam dynamics in this structure, demonstrating a method for keeping a beam confined to the waveguide. We also discuss material and fabrication considerations. Since accelerating gradient is limited by optical damage to the structure, the damage threshold of the dielectric is a critical parameter. We experimentally measure the damage threshold of silicon for picosecond pulses in the infrared, and determine that our structure is capable of sustaining an accelerating gradient of 300 MV/m at 1550 nm. Finally, we discuss possibilities for manufacturing these structures using common microfabrication techniques.

  15. Fabrication and evaluation of photonic metamaterial crystal

    NASA Astrophysics Data System (ADS)

    Tanabete, S.; Nakagawa, Y.; Okamoto, T.; Haraguchi, M.; Isu, T.; Shinomiya, G.

    2013-09-01

    Many researching efforts have been reported to seek various fundamental LC resonance structures, recently. But still the Split Ring Resonator (SRR) is the most famous and major fundamental LC-resonance structure used in the metamaterial. We employed SRR structure as the fundamental LC-resonance mechanism to fabricate photonic crystal with periodic arrangement of two different metamaterial areas composed from SRR arrays on the dielectric substrate. We developed Photonic Metamaterial Crystal (PMC) to realize the more advanced and versatile functions of the metamaterial by 1 dimensional or 2 dimensional periodic arranging of two metamaterial sections which have different dispersion properties due to the different size of SRR structures each other. In this paper, we report the fabrication process, estimation of PMC properties and some possible future application prospects, for instance the PMC waveguide structures and nonlinear properties of PMC observed as selective LC-resonant properties in Raman mapping analysis of PMC. These are quite interesting characters of PMC and the attractive applications as the PMC devices.

  16. Near-unity coupling efficiency of a quantum emitter to a photonic crystal waveguide.

    PubMed

    Arcari, M; Söllner, I; Javadi, A; Lindskov Hansen, S; Mahmoodian, S; Liu, J; Thyrrestrup, H; Lee, E H; Song, J D; Stobbe, S; Lodahl, P

    2014-08-29

    A quantum emitter efficiently coupled to a nanophotonic waveguide constitutes a promising system for the realization of single-photon transistors, quantum-logic gates based on giant single-photon nonlinearities, and high bit-rate deterministic single-photon sources. The key figure of merit for such devices is the β factor, which is the probability for an emitted single photon to be channeled into a desired waveguide mode. We report on the experimental achievement of β=98.43%±0.04% for a quantum dot coupled to a photonic crystal waveguide, corresponding to a single-emitter cooperativity of η=62.7±1.5. This constitutes a nearly ideal photon-matter interface where the quantum dot acts effectively as a 1D "artificial" atom, since it interacts almost exclusively with just a single propagating optical mode. The β factor is found to be remarkably robust to variations in position and emission wavelength of the quantum dots. Our work demonstrates the extraordinary potential of photonic crystal waveguides for highly efficient single-photon generation and on-chip photon-photon interaction. PMID:25215983

  17. Single-photon experiments with liquid crystals for quantum science and quantum engineering applications

    NASA Astrophysics Data System (ADS)

    Lukishova, Svetlana G.; Liapis, Andreas C.; Bissell, Luke J.; Gehring, George M.; Winkler, Justin M.; Boyd, Robert W.

    2015-03-01

    We present here our results on using liquid crystals in experiments with nonclassical light sources: (1) single-photon sources exhibiting antibunching (separation of all photons in time), which are key components for secure quantum communication systems, and (2) entangled photon source with photons exhibiting quantum interference in a Hong-Ou- Mandel interferometer. In the first part, cholesteric liquid crystal hosts were used to create definite circular polarization of antibunched photons emitted by nanocrystal quantum dots. If the photon has unknown polarization, filtering it through a polarizer to produce the desired polarization for quantum key distribution with bits based on polarization states of photons will reduce by half the efficiency of a quantum cryptography system. In the first part, we also provide our results on observation of a circular polarized microcavity resonance in nanocrystal quantum dot fluorescence in a 1-D chiral photonic bandgap cholesteric liquid crystal microcavity. In the second part of this paper with indistinguishable, time-entangled photons, we demonstrate our experimental results on simulating quantum-mechanical barrier tunnelling phenomena. A Hong-Ou-Mandel dip (quantum interference effect) is shifted when a phase change was introduced on the way of one of entangled photons in pair (one arm of the interferometer) by inserting in this arm an electrically controlled planar-aligned nematic liquid crystal layer between two prisms in the conditions close to a frustrated total internal reflection. By applying different AC-voltages to the planar-aligned nematic layer and changing its refractive index, we can obtain various conditions for incident photon propagation - from total reflection to total transmission. Measuring changes of tunnelling times of photon through this structure with femtosecond resolution permitted us to answer some unresolved questions in quantum-mechanical barrier tunnelling phenomena.

  18. Photonic Crystal Enhanced Fluorescence for Early Breast Cancer Biomarker Detection

    PubMed Central

    Cunningham, Brian T.; Zangar, Richard C.

    2013-01-01

    Photonic crystal surfaces offer a compelling platform for improving the sensitivity of surface-based fluorescent assays used in disease diagnostics. Through the complementary processes of photonic crystal enhanced excitation and enhanced extraction, a periodic dielectric-based nanostructured surface can simultaneously increase the electric field intensity experienced by surface-bound fluorophores and increase the collection efficiency of emitted fluorescent photons. Through the ability to inexpensively fabricate photonic crystal surfaces over substantial surface areas, they are amenable to single-use applications in biological sensing, such as disease biomarker detection in serum. In this review, we will describe the motivation for implementing high-sensitivity, multiplexed biomarker detection in the context of breast cancer diagnosis. We will summarize recent efforts to improve the detection limits of such assays though the use of photonic crystal surfaces. Reduction of detection limits is driven by low autofluorescent substrates for photonic crystal fabrication, and detection instruments that take advantage of their unique features. PMID:22736539

  19. Plasmon-polariton and 1D Cantor photonic superlattices

    NASA Astrophysics Data System (ADS)

    Mejía-Salazar, J. R.; Porras-Montenegro, N.; Reyes-Gómez, E.; Cavalcanti, S. B.; Oliveira, L. E.

    2014-05-01

    We have used the transfer-matrix approach for one-dimensional Cantor photonic superlattices, and studied the plasmon-polariton modes for a multilayered system composed by alternating layers of positive and dispersive materials. Results indicate that the corresponding plasmon-polariton modes, which show up for oblique incidence, strongly depend on the Cantor step, and the plasmon-polariton subbands are associated with the number of metamaterial layers contained in the elementary cell. Moreover, we have studied the = 0 non-Bragg gap in such fractal photonic superlattices and characterized its behavior as function of the steps of the Cantor series.

  20. Two-dimensional metal-glass photonic crystal

    NASA Astrophysics Data System (ADS)

    Pysz, Dariusz; Kujawa, Ireneusz; Stępień, Ryszard; Dominiak, Radosław; Pniewski, Jacek; Szoplik, Tomasz

    2007-04-01

    We present recent achievements in fabricating a two-dimensional (2D) photonic crystal in the form of a bundle of parallel micro- or nanowires embedded in glass matrix. The method is similar to that of sequential thinning used for fabrication of photonic crystal fibers. We discuss technological issues that aim at preservation of regularity of photonic crystal lattice and uniformity of wire diameters. Proper selection of a melting point of metal alloy and the range of temperatures of glass viscosity leads to reduction of regularity losses resulting from sequential processes of drawing. Measured distributions of crystal lattices, wire diameters and shapes of wires are used to simulate photonic band structure of fabricated crystals. This work is directed toward fabrication of a photonic crystal showing the negative refraction in the near infrared and visible spectral range.

  1. Theoretical design of photonic crystal devices for integrated optical circuits

    NASA Astrophysics Data System (ADS)

    Mekis, Attila

    2000-12-01

    In this thesis we investigate novel photonic crystal devices that can be used as building blocks of all- optical circuits. We contrast the behavior of light in photonic crystal systems and in their traditional counterparts. We exhibit that bends in photonic crystals are able to transmit light with over 90% efficiency for large bandwidths and with 100% efficiency for specific frequencies. In contrast to traditional waveguides, bound states in photonic crystal waveguides can also exist in constrictions and above the cutoff frequency. We discuss how to lower reflections encountered when photonic crystal waveguides are terminated, both in an experimental setup as well as in numerical simulations. We show that light can be very efficiently coupled into and out of photonic crystal waveguides using tapered dielectric waveguides. In time-domain simulations of photonic crystal waveguides, spurious reflections from cell edges can be eliminated by terminating the waveguide with a Bragg reflector waveguide. We demonstrate novel lasing action in two-dimensional photonic crystal slabs with gain media, where lasing occurs at saddle points in the band structure, in contrast to one-dimensional photonic crystals. We also design a photonic crystal slab with organic gain media that has a TE-like pseudogap. We demonstrate that such a slab can support a high- Q defect mode, enabling low threshold lasing, and we discuss how the quality factor depends on the design parameters. We also propose to use two- dimensional photonic crystal slabs as directionally efficient free-space couplers. We draft methods to calculate the coupling constant both numerically and analytically, using a finite-difference time-domain method and the volume current method with a Green's function approach, respectively. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

  2. Extremely low-loss terahertz waveguide based on silicon photonic-crystal slab.

    PubMed

    Tsuruda, Kazuisao; Fujita, Masayuki; Nagatsuma, Tadao

    2015-12-14

    We pursued the extremely low loss of photonic-crystal waveguides composed of a silicon slab with high resistivity (20 kΩ-cm) in the terahertz region. Propagation and bending losses as small as <0.1 dB/cm (0.326-0.331 THz) and 0.2 dB/bend (0.323-0.331 THz), respectively, were achieved in the 0.3-THz band. We also developed 1.5-Gbit/s terahertz links and demonstrated an error-free uncompressed high-definition video transmission by using a photonic-crystal waveguide with a length of as long as 50 cm and up to 28 bends thanks to the low-loss properties. Our results show the potential of photonic crystals for application as terahertz integration platforms. PMID:26698989

  3. Three-dimensional photonic crystals fabricated by simultaneous multidirectional etching

    NASA Astrophysics Data System (ADS)

    Kitano, Keisuke; Suzuki, Katsuyoshi; Ishizaki, Kenji; Noda, Susumu

    2015-04-01

    We discuss three-dimensional (3D) photonic crystals fabricated by simultaneous multidirectional plasma etching. First, we investigate a method for controlling the ion sheath used in reactive ion etching for obtaining multidirectional etching. We then discuss the fabrication tolerance from an analytical perspective. Based on our results, we demonstrate the fabrication of 3D photonic crystals with thicknesses of 1, 1.5, and 2 lattice periods in the surface-normal direction on single-crystalline silicon wafers, which show high reflectance (˜100 %) and low transmittance (-17 dB ) at optical communication wavelengths, suggesting the formation of a complete photonic band gap. We reveal that the shape of the etched holes limits the performance of 3D photonic crystals and suggest possible ways to improve the band-gap effect. Moreover, we show that 3D photonic crystals with short lattice constants show high reflectance (˜80 %) at visible to near-infrared wavelengths. By investigating the influence of absorption on the characteristics of 3D photonic crystals, we reveal that the reflectance remains as high as 94% in the photonic band-gap range even when the absorption of silicon is taken into account. We find that a unique increase of absorption occurs at several discrete wavelengths below the photonic band gap, suggesting the possibility of manipulating light absorption. These results not only simplify the fabrication of 3D photonic crystals, but also provide a basis for realizing 3D photonic nanostructures that include other materials.

  4. Visualization of the light injection in one dimensional Photonic Crystals.

    NASA Astrophysics Data System (ADS)

    Archuleta-Garcia, Raul

    2005-03-01

    In this work we present time variation simulations of the light injection in one dimension photonic crystals (1D-PC). This phenomenon is due to the coupling of an incoming plane-wave to the discrete vibration modes in finite 1D-PC. In order to present a live animation of the system we proceed in two stages. First, we present the discrete relation dispersion and then we choose the better combination of frequency and wave-vector. Second, for this combination we reconstruct the field amplitudes in each one of the media. This phenomenon has been described in three previous works [1-3] for the case of a metal-dielectric-metal system. In this work we present the simulation of this system and also the extension of the idea for the case of a multilayer system. The visualization of the electromagnetic field gives a better comprehension of the phenomena. [1]R. Garcia-Llamas, J.A. Gaspar-Armenta, F.Ramos-Mendieta, R.F. Haglund, R. Ruiz. ``Design, manufacturing and testing of planar optical waveguide devices'',.), Proceedings of SPIE, vol. 4439, 2001, pp 88-94. [2] F. Villa, T. Lopez-Rios, L.E. Regalado, ``Electromagnetic modes in metal-insulator-metal structures'', Phys. Rev. B 63 (2001) 165103. [3] A.S. Ramirez-Duverger, R. Garcia-Llamas, ``Light scattering from a multimode waveguide of planar metalic walls'', Optics Communications, (2003)

  5. Photonic crystal chips for optical communications and quantum information processing

    NASA Astrophysics Data System (ADS)

    Englund, Dirk; Fushman, Ilya; Faraon, Andrei; Ellis, Bryan; Vučković, Jelena

    2008-08-01

    We discuss recent our recent progress on functional photonic crystals devices and circuits for classical and quantum information processing. For classical applications, we have demonstrated a room-temperature-operated, low threshold, nanocavity laser with pulse width in the picosecond regime; and an all-optical switch controlled with 60 fJ pulses that shows switching time on the order of tens of picoseconds. For quantum information processing, we discuss the promise of quantum networks on multifunctional photonic crystals chips. We also discuss a new coherent probing technique of quantum dots coupled to photonic crystal nanocavities and demonstrate amplitude and phase nonlinearities realized with control beams at the single photon level.

  6. Controlled coupling of photonic crystal cavities using photochromic tuning

    NASA Astrophysics Data System (ADS)

    Cai, Tao; Bose, Ranojoy; Solomon, Glenn S.; Waks, Edo

    2013-04-01

    We present a method to control the resonant coupling interaction in a coupled-cavity photonic crystal molecule by using a local and reversible photochromic tuning technique. We demonstrate the ability to tune both a two-cavity and a three-cavity photonic crystal molecule through the resonance condition by selectively tuning the individual cavities. Using this technique, we can quantitatively determine important parameters of the coupled-cavity system such as the photon tunneling rate. This method can be scaled to photonic crystal molecules with larger numbers of cavities, which provides a versatile method for studying strong interactions in coupled resonator arrays.

  7. Waveguide circuits in three-dimensional photonic crystals

    SciTech Connect

    Biswas, Rana; Christensen, C.; Muehlmeier, J.; Tuttle, G.; Ho, K.-M.

    2008-04-07

    Waveguide circuits in three-dimensional photonic crystals with complete photonic band gaps are simulated with finite difference time domain (FDTD) simulations, and compared with measurements on microwave scale photonic crystals. The transmission through waveguide bends critically depends on the photonic crystal architecture in the bend region. We have found experimentally and theoretically, a new waveguide bend configuration consisting of overlapping rods in the bend region, that performs better than the simple waveguide bend of terminated rods, especially in the higher frequency portion of the band. Efficient beam splitters with this junction geometry are also simulated.

  8. Two-photon-induced singlet fission in rubrene single crystal

    NASA Astrophysics Data System (ADS)

    Ma, Lin; Galstyan, Gegham; Zhang, Keke; Kloc, Christian; Sun, Handong; Soci, Cesare; Michel-Beyerle, Maria E.; Gurzadyan, Gagik G.

    2013-05-01

    The two-photon-induced singlet fission was observed in rubrene single crystal and studied by use of femtosecond pump-probe spectroscopy. The location of two-photon excited states was obtained from the nondegenerate two-photon absorption (TPA) spectrum. Time evolution of the two-photon-induced transient absorption spectra reveals the direct singlet fission from the two-photon excited states. The TPA absorption coefficient of rubrene single crystal is 52 cm/GW at 740 nm, as obtained from Z-scan measurements. Quantum chemical calculations based on time-dependent density functional theory support our experimental data.

  9. Optical nanofiber-based photonic crystal cavity.

    PubMed

    Nayak, K P; Zhang, Pengfei; Hakuta, K

    2014-01-15

    We demonstrate the fabrication of photonic crystal (PhC) cavities on optical nanofibers using femtosecond laser ablation. PhC cavities with cavity lengths varying from 0.54 to 3.43 mm are fabricated by controlling the profile of the nanocrater array formed on the nanofiber. Such PhC cavities show high transmission of 87% for a finesse of 39. For higher finesse values from 150 to 500, the transmission can still be maintained at 20%-25%. Due to the strong confinement of the field and the efficient coupling to single-mode optical fibers, such nanofiber-based PhC cavities may become an interface between quantum and classical networks. PMID:24562114

  10. Nonlinear waveguide optics and photonic crystal fibers.

    PubMed

    Knight, J C; Skryabin, D V

    2007-11-12

    Focus Serial: Frontiers of Nonlinear Optics

    Optical fibers and waveguides provide unique and distinct environments for nonlinear optics, because of the combination of high intensities, long interaction lengths, and control of the propagation constants. They are also becoming of technological importance. The topic has a long history but continues to generate rapid development, most recently through the invention of the new forms of optical fiber collectively known as photonic crystal fibers. Some of the discoveries and ideas from the new fibers look set to have lasting influence in the broader field of guided-wave nonlinear optics. In this paper we introduce some of these ideas. PMID:19550822

  11. Enhanced photoacoustic detection using photonic crystal substrate

    SciTech Connect

    Zhao, Yunfei; Liu, Kaiyang; McClelland, John; Lu, Meng

    2014-04-21

    This paper demonstrates the enhanced photoacoustic sensing of surface-bound light absorbing molecules and metal nanoparticles using a one-dimensional photonic crystal (PC) substrate. The PC structure functions as an optical resonator at the wavelength where the analyte absorption is strong. The optical resonance of the PC sensor provides an intensified evanescent field with respect to the excitation light source and results in enhanced optical absorption by surface-immobilized samples. For the analysis of a light absorbing dye deposited on the PC surface, the intensity of photoacoustic signal was enhanced by more than 10-fold in comparison to an un-patterned acrylic substrate. The technique was also applied to detect gold nanorods and exhibited more than 40 times stronger photoacoustic signals. The demonstrated approach represents a potential path towards single molecule absorption spectroscopy with greater performance and inexpensive instrumentation.

  12. Photonic crystal cavities with metallic Schottky contacts

    SciTech Connect

    Quiring, W.; Al-Hmoud, M.; Reuter, D.; Zrenner, A.; Rai, A.; Wieck, A. D.

    2015-07-27

    We report about the fabrication and analysis of high Q photonic crystal cavities with metallic Schottky-contacts. The structures are based on GaAs n-i membranes with an InGaAs quantum well in the i-region and nanostructured low ohmic metal top-gates. They are designed for photocurrent readout within the cavity and fast electric manipulations. The cavity structures are characterized by photoluminescence and photocurrent spectroscopy under resonant excitation. We find strong cavity resonances in the photocurrent spectra and surprisingly high Q-factors up to 6500. Temperature dependent photocurrent measurements in the region between 4.5 K and 310 K show an exponential enhancement of the photocurrent signal and an external quantum efficiency up to 0.26.

  13. Asymptotics for metamaterials and photonic crystals.

    PubMed

    Antonakakis, T; Craster, R V; Guenneau, S

    2013-04-01

    Metamaterial and photonic crystal structures are central to modern optics and are typically created from multiple elementary repeating cells. We demonstrate how one replaces such structures asymptotically by a continuum, and therefore by a set of equations, that captures the behaviour of potentially high-frequency waves propagating through a periodic medium. The high-frequency homogenization that we use recovers the classical homogenization coefficients in the low-frequency long-wavelength limit. The theory is specifically developed in electromagnetics for two-dimensional square lattices where every cell contains an arbitrary hole with Neumann boundary conditions at its surface and implemented numerically for cylinders and split-ring resonators. Illustrative numerical examples include lensing via all-angle negative refraction, as well as omni-directive antenna, endoscope and cloaking effects. We also highlight the importance of choosing the correct Brillouin zone and the potential of missing interesting physical effects depending upon the path chosen. PMID:23633908

  14. Suspended polymeric photonic crystals: simulation and fabrication

    NASA Astrophysics Data System (ADS)

    Rebigan, R.; Dinescu, A.; Kusko, C.; Gavrila, R.; Cristea, D.; Obreja, C.; Schiopu, P.

    2010-11-01

    In this paper we present simulation of transmission / reflection spectra of polymeric rectangular and hexagonal photonic crystals (PC) as well as the propagation of radiation in a hexagonal PC - based waveguide. The polymeric PC are periodic structures consisting in square arrays of holes configured in suspended membranes of PMMA with different diameters and pitch (100 nm diameter with 500 nm, respectively 800 nm pitch; 200 nm diameter with 500 nm pitch; 400 nm diameter with 700 nm pitch). For fabrication, we propose the bi-layer EBL technique based on simultaneous patterning of a bottom sacrificial layer (LOR 5A - Microchem Corporation) and a positive electron resist (PMMA of different molecular weights). Characterization of nanostructures was performed using SEM imaging and AFM measurements .

  15. Surface Brillouin scattering in photonic crystal fibers.

    PubMed

    Tchahame, Joël Cabrel; Beugnot, Jean-Charles; Huy, Kien Phan; Laude, Vincent; Kudlinski, Alexandre; Sylvestre, Thibaut

    2016-07-15

    We report, to the best of our knowledge, the first experimental observation of surface Brillouin scattering in silica-based photonic crystal fibers, arising from the interaction between guided light and surface acoustic waves. This was achieved using small-core and high air-filling fraction microstructured fibers that enable a strong opto-acoustic coupling near the air holes while mitigating the acoustic leakages in the microstructured cladding. It is further shown that this new type of light scattering is highly sensitive to the fiber air-hole microstructure, thus providing a passive and efficient way to control it. Our observations are confirmed through numerical simulations of the elastodynamics equation. PMID:27420512

  16. Squeezed state generation in photonic crystal microcavities.

    PubMed

    Banaee, M G; Young, Jeff F

    2008-12-01

    The feasibility of using a parametric down-conversion process to generate squeezed electromagnetic states in three dimensional photonic crystal microcavity structures is investigated for the first time. The spectrum of the squeezed light is theoretically calculated by using an open cavity quantum mechanical formalism. The cavity communicates with two main channels, which model vertical radiation losses and coupling into a single-mode waveguide respectively. The amount of squeezing is determined by the correlation functions relating the field quadratures of light coupled into the waveguide. All of the relevant model parameters are realistically estimated for structures made in Al0.3Ga0.7As, using finite-difference time-domain simulations. Squeezing up to approximately 30% below the shot noise level is predicted for 10 mW average power, 80 MHz repetition, 500 ps excitation pulses using in a [111] oriented wafer. PMID:19065230

  17. A laminar solid core photonic crystal waveguide

    NASA Astrophysics Data System (ADS)

    Willig, R. L.

    2005-11-01

    A one-dimensional model is presented to explain the physics of solid core photonic crystal fibers. The model provides a clear way to demonstrate many of the interesting characteristics of these fibers: variation of cladding index with wavelength, endlessly single-mode operation, short wavelength index limit, long wavelength index limit, and variation of these properties with the air/silica fraction. The effective index is calculated for a laminar cladding consisting of periodic layers of alternating high and low index dielectrics. The waveguide model consists of the same periodic layers surrounding a high-index core through which most of the light propagates. The light is confined by total internal reflection. The model is shown to be an accurate analogue for a more complicated two-dimensional finned dielectric waveguide.

  18. Stable planar mesoscopic photonic crystal cavities.

    PubMed

    Magno, G; Monmayrant, A; Grande, M; Lozes-Dupuy, F; Gauthier-Lafaye, O; Calò, G; Petruzzelli, V

    2014-07-15

    Mesoscopic self-collimation (MSC) in mesoscopic photonic crystals with high reflectivity is exploited to realize a novel high Q-factor cavity by means of mesoscopic PhC planar mirrors. These mirrors efficiently confine a mode inside a planar Fabry-Perot-like cavity, that results from a beam focusing effect that stabilizes the cavity even for small beam sizes, resembling the focusing behavior of curved mirrors. Moreover, they show an improved reflectivity with respect to their standard distributed Bragg reflector counterparts that allows higher compactness. A Q-factor higher than 10⁴ has been achieved for an optimized 5-period-long mirror cavity. The optimization of the Q-factor and the performances in terms of energy storage, field enhancement, and confinement are detailed. PMID:25121692

  19. Fano resonance in anodic aluminum oxide based photonic crystals

    PubMed Central

    Shang, Guo Liang; Fei, Guang Tao; Zhang, Yao; Yan, Peng; Xu, Shao Hui; Ouyang, Hao Miao; De Zhang, Li

    2014-01-01

    Anodic aluminum oxide based photonic crystals with periodic porous structure have been prepared using voltage compensation method. The as-prepared sample showed an ultra-narrow photonic bandgap. Asymmetric line-shape profiles of the photonic bandgaps have been observed, which is attributed to Fano resonance between the photonic bandgap state of photonic crystal and continuum scattering state of porous structure. And the exhibited Fano resonance shows more clearly when the sample is saturated ethanol gas than air-filled. Further theoretical analysis by transfer matrix method verified these results. These findings provide a better understanding on the nature of photonic bandgaps of photonic crystals made up of porous materials, in which the porous structures not only exist as layers of effective-refractive-index material providing Bragg scattering, but also provide a continuum light scattering state to interact with Bragg scattering state to show an asymmetric line-shape profile. PMID:24398625

  20. Superconducting Photonic Crystal with Nanostrips for Mid-Infrared Applications

    SciTech Connect

    Ooi, C. H. Raymond

    2011-03-30

    One dimensional photonic crystal with superconducting nanostrips and semiconductor materials can be tailored to have narrow bands, with either large transmission or large reflection. Based on the reflection and transmission coefficients, we study the temporal dynamics of the reflected and transmitted pulses from the finite photonic crystal. The output pulse dynamics show slow light effect around the narrow bands that can be useful for photonic technologies.

  1. Optical properties in one-dimensional graded soft photonic crystals with ferrofluids

    NASA Astrophysics Data System (ADS)

    Fan, Chunzhen; Wang, Junqiao; Zhu, Shuangmei; He, Jinna; Ding, Pei; Liang, Erjun

    2013-05-01

    We theoretically investigate the optical properties in one-dimensional graded soft photonic crystals (1D GSPCs). The proposed structure is constituted of the stacked ferrofluids layer and the dielectric layer. Due to the supermagnetic response of the ferromagnetic nanoparticles, they will align in a line under the influence of the initiated magnetic field, thereby modulating the refractive index of the ferrofluids layer. By resorting to the transfer matrix method, the dispersion relation, transmittance and reflectance in 1D GSPCs were calculated. Numerical results show that a broad photonic band gap appears in such systems, which can even be broadened by increasing the volume fraction of ferromagnetic nanoparticles. Moreover, perfect transmittance of our proposed structure can be realized with an increased number of ferrofluid layers. In comparison with conventional PCs materials, 1D GSPCs composed of liquid material offer a very flexible route to implementation, which can be widely used in the application of optical filters, waveguides, reflectors and so on.

  2. Modeling of the photonic crystal waveguide modes with the FDTD method

    NASA Astrophysics Data System (ADS)

    Rai, Buddhi

    2012-04-01

    The electromagnetic modes are investigated using a simple 1D implementation of the FDTD numerical algorithm to a model of 1D photonic crystal (layered media). The fields Ez and Hy are simulated along the x-axis, the propagation direction. Source implementation and the effects of various boundary conditions such as ABC, Mur on TF/SF fields are investigated. Of particular focus in this paper is, for example, on investigating the guided and/or radiation modes at a stop band frequency of the photonic crystal formed of linear and Kerr nonlinear media. Such structures exhibit interesting transmission and reflection properties that make them suitable for optical devices with frequency/wavelength tunable characteristics.

  3. Thermally Driven Photonic Actuator Based on Silica Opal Photonic Crystal with Liquid Crystal Elastomer.

    PubMed

    Xing, Huihui; Li, Jun; Shi, Yang; Guo, Jinbao; Wei, Jie

    2016-04-13

    We have developed a novel thermoresponsive photonic actuator based on three-dimensional SiO2 opal photonic crystals (PCs) together with liquid crystal elastomers (LCEs). In the process of fabrication of such a photonic actuator, the LCE precursor is infiltrated into the SiO2 opal PC followed by UV light-induced photopolymerization, thereby forming the SiO2 opal PC/LCE composite film with a bilayer structure. We find that this bilayer composite film simultaneously exhibits actuation behavior as well as the photonic band gap (PBG) response to external temperature variation. When the SiO2 opal PC/LCE composite film is heated, it exhibits a considerable bending deformation, and its PBG shifts to a shorter wavelength at the same time. In addition, this actuation is quite fast, reversible, and highly repeatable. The thermoresponsive behavior of the SiO2 opal PC/LCE composite films mainly derives from the thermal-driven change of nematic order of the LCE layer which leads to the asymmetric shrinkage/expansion of the bilayer structure. These results will be of interest in designing optical actuator systems for environment-temperature detection. PMID:26996608

  4. Topological modes in one-dimensional solids and photonic crystals

    NASA Astrophysics Data System (ADS)

    Atherton, Timothy J.; Butler, Celia A. M.; Taylor, Melita C.; Hooper, Ian R.; Hibbins, Alastair P.; Sambles, J. Roy; Mathur, Harsh

    2016-03-01

    It is shown theoretically that a one-dimensional crystal with time-reversal and particle-hole symmetries is characterized by a topological invariant that predicts the existence or otherwise of edge states. This is confirmed experimentally through the construction and simulation of a photonic crystal analog in the microwave regime. It is shown that the edge mode couples to modes external to the photonic crystal via a Fano resonance.

  5. Optical bullets in (2+1)D photonic structures and their interaction with localized defects

    NASA Astrophysics Data System (ADS)

    Dohnal, Tomas

    2005-11-01

    This dissertation studies light propagation in Kerr-nonlinear two dimensional waveguides with a Bragg resonant, periodic structure in the propagation direction. The model describing evolution of the electric field envelopes is the system of 2D Nonlinear Coupled Mode Equations (2D CME). The periodic structure induces a range of frequencies (frequency gap) in which linear waves do not propagate. It is shown that, similarly to the ID case of a fiber grating, the 2D nonlinear system supports localized solitary wave solutions, referred to as 2D gap solitons, which have frequencies inside the linear gap and can travel at, any speed smaller than or equal to the speed of light in the corresponding homogeneous medium. Such solutions are constructed numerically via Newton's iteration. Convergence is obtained only near the upper edge of the gap. Gap solitons with a nonzero velocity are constructed by numerically following a bifurcation curve parameterized by the velocity v. It is shown that gap solitons are saddle points of the corresponding Hamiltonian functional and that no (constrained) local minima of the Hamiltonian exist. The linear stability problem is formulated and reasons for the failure of the standard Hamiltonian PDE approach for determining linear stability are discussed. In the second part of the dissertation interaction of 2D gap solitons with localized defects is studied and trapping of slow enough 2D gap solitons is demonstrated. This study builds on [JOSA B 19, 1635 (2002)], where such trapping of 1D gap solitons is considered. Analogously to this 1D problem trapping in the 2D model is explained as a resonant energy transfer into one or more defect modes existent for the particular defect. For special localized defects exact linear modes are found explicitly via the separation of variables. Numerical computation of linear defect modes is used for more general defects. Corresponding nonlinear modes are then constructed via Newton's iteration by following a

  6. Coupling light in photonic crystal waveguides: A review

    NASA Astrophysics Data System (ADS)

    Dutta, Hemant Sankar; Goyal, Amit Kumar; Srivastava, Varun; Pal, Suchandan

    2016-07-01

    Submicron scale structures with high index contrast are key to compact structures for realizing photonic integrated structures. Ultra-compact optical devices in silicon-on-insulator (SOI) substrates serve compatibility with semiconductor fabrication technology leading to reduction of cost and mass production. Photonic crystal structures possess immense potential for realizing various compact optical devices. However, coupling light to photonic crystal waveguide structures is crucial in order to achieve strong transmission and wider bandwidth of signal. Widening of bandwidth will increase potential for various applications and high transmission will make easy signal detection at the output. In this paper, the techniques reported so far for coupling light in photonic crystal waveguides have been reviewed and analyzed so that a comprehensive guide for an efficient coupling to photonic crystal waveguides can be made possible.

  7. High-Q CMOS-integrated photonic crystal microcavity devices

    PubMed Central

    Mehta, Karan K.; Orcutt, Jason S.; Tehar-Zahav, Ofer; Sternberg, Zvi; Bafrali, Reha; Meade, Roy; Ram, Rajeev J.

    2014-01-01

    Integrated optical resonators are necessary or beneficial in realizations of various functions in scaled photonic platforms, including filtering, modulation, and detection in classical communication systems, optical sensing, as well as addressing and control of solid state emitters for quantum technologies. Although photonic crystal (PhC) microresonators can be advantageous to the more commonly used microring devices due to the former's low mode volumes, fabrication of PhC cavities has typically relied on electron-beam lithography, which precludes integration with large-scale and reproducible CMOS fabrication. Here, we demonstrate wavelength-scale polycrystalline silicon (pSi) PhC microresonators with Qs up to 60,000 fabricated within a bulk CMOS process. Quasi-1D resonators in lateral p-i-n structures allow for resonant defect-state photodetection in all-silicon devices, exhibiting voltage-dependent quantum efficiencies in the range of a few 10 s of %, few-GHz bandwidths, and low dark currents, in devices with loaded Qs in the range of 4,300–9,300; one device, for example, exhibited a loaded Q of 4,300, 25% quantum efficiency (corresponding to a responsivity of 0.31 A/W), 3 GHz bandwidth, and 30 nA dark current at a reverse bias of 30 V. This work demonstrates the possibility for practical integration of PhC microresonators with active electro-optic capability into large-scale silicon photonic systems. PMID:24518161

  8. Photonic band gap in 1D multilayers made by alternating SiO2 or PMMA with MoS2 or WS2 monolayers

    NASA Astrophysics Data System (ADS)

    Figueroa del Valle, Diana Gisell; Aluicio-Sarduy, Eduardo; Scotognella, Francesco

    2015-10-01

    Atomically thin molybdenum disulfide (MoS2) and tungsten disulfide (WS2) are very interesting two dimensional materials for optics and electronics. In this work we show the possibility to obtain one-dimensional photonic crystals consisting of low-cost and easy processable materials, as silicon dioxide (SiO2) or poly methyl methacrylate (PMMA), and of MoS2 or WS2 monolayers. We have simulated the transmission spectra of the photonic crystals using the transfer matrix method and employing the wavelength dependent refractive indexes of the materials. This study envisages the experimental fabrication of these new types of photonic crystals for photonic and light emission applications.

  9. Three dimensional reflectance properties of superconductor-dielectric photonic crystal

    NASA Astrophysics Data System (ADS)

    Pandey, G. N.; Pandey, J. P.; Pandey, U. K.; Sancheti, Bhagyashree; Ojha, S. P.

    2016-05-01

    In this present communication, we have studied the optical properties of Photonics Crystals with super conducting constituent using the TMM method for a stratified medium. We also studied the three dimensional reflectance property of superconductor-dielectric photonic crystal at different temperature and thickness. From above study we show that the superconductor-dielectric photonic crystal may be used as broad band reflector and omnidirectional reflector at low temperature below to the critical temperature. Such property may be applied to make of the reflector which can be used in low temperature region.

  10. Three-Dimensional Photonic Crystal Laser-Driven Accelerator Structures

    SciTech Connect

    Cowan, B.; /SLAC

    2006-09-07

    We discuss simulated photonic crystal structure designs for laser-driven particle acceleration, focusing on three-dimensional planar structures based on the so-called ''woodpile'' lattice. We describe guiding of a speed-of-light accelerating mode by a defect in the photonic crystal lattice and discuss the properties of this mode, including particle beam dynamics and potential coupling methods for the structure. We also discuss possible materials and power sources for this structure and their effects on performance parameters, as well as possible manufacturing techniques and the required tolerances. In addition we describe the computational technique and possible improvements in numerical modeling that would aid development of photonic crystal structures.

  11. Recent progress and novel applications of photonic crystal fibers

    NASA Astrophysics Data System (ADS)

    Arismar Cerqueira, S., Jr.

    2010-02-01

    Photonic crystal fibers present a wavelength-scale periodic microstructure running along their length. Their core and two-dimensional photonic crystal might be based on varied geometries and materials, enabling light guidance due to different propagation mechanisms in an extremely large wavelength range, extending to the terahertz regions. As a result, these fibers have revolutionized the optical fiber technology by means of creating new degrees of freedom in the fiber design, fabrication and applicability. This report aims to provide a detailed statement on the recent progress and novel potential applications of photonic crystal fibers.

  12. Quantitative modeling of fluorescent emission in photonic crystals

    NASA Astrophysics Data System (ADS)

    Gutmann, Johannes; Zappe, Hans; Goldschmidt, Jan Christoph

    2013-11-01

    Photonic crystals affect the photon emission of embedded emitters due to an altered local density of photon states (LDOS). We review the calculation of the LDOS from eigenmodes in photonic crystals and propose a rate equation model for fluorescent emitters to determine the changes in emission induced by the LDOS. We show how to calculate the modifications of three experimentally accessible characteristics: emission spectrum (spectral redistribution), emitter quantum yield, and fluorescence lifetime. As an example, we present numerical results for the emission of the dye Rhodamine B inside an opal photonic crystal. For such photonic crystals with small permittivity contrast, the LDOS is only weakly modified, resulting in rather small changes. We point out that in experiments, however, usually only part of the emitted light is detected, which can have a very different spectral distribution (e.g., due to a photonic band gap in the direction of detection). We demonstrate the calculation of this detected spectrum for a typical measurement setup. With this reasoning, we explain the previously not fully understood experimental observation that strong spectral modifications occurred, while at the same time only small changes in lifetime were found. With our approach, the mentioned effects can be quantitatively calculated for fluorescent emitters in any photonic crystal.

  13. Photonic crystal structures for efficent localization or extraction of light

    NASA Astrophysics Data System (ADS)

    Vuckovic, Jelena

    Three-dimensional (3D) photonic crystals offer the opportunity of light manipulation in all directions in space, but they are very difficult to fabricate. On the other hand, planar photonic crystals are much simpler to make, but they exhibit only a "quasi-3D" confinement, resulting from the combined action of 2D photonic crystal and internal reflection. The imperfect confinement in the third dimension produces some unwanted out-of-plane loss, which is usually a limiting factor in performance of these structures. This thesis proposes how to fully take advantage of the relatively simple fabrication of planar photonic crystals, by addressing a problem of loss-reduction. One of the greatest challenges in photonics is a construction of optical microcavities with small mode volumes and large quality factors, for efficient localization of light. Beside standard applications of these structures (such as lasers or filters), they can potentially be used for cavity QED experiments, or as building blocks for quantum networks. This work also presents the design and fabrication of optical microcavities based on planar photonic crystals, with mode volumes of the order of one half of cubic wavelength of light (measured in material) and with Q factors predicted to be even larger than 10 4. In addition to photonic crystals fabricated in semiconductors, we also address interesting properties of metallic photonic crystals and present our theoretical and experimental work on using them to improve the output of light emissive devices. Feature sizes of structures presented here are below those achievable by photolithography. Therefore, a high resolution lithography is necessary for their fabrication. The presently used e-beam writing techniques suffer from limitations in speed and wafer throughput, and they represent a huge obstacle to commercialization of photonic crystals. Our preliminary work on electron beam projection lithography, the technique that could provide us with the speed

  14. 1D magnetic interactions in Cu(II) oxovanadium phosphates (VPO), magnetic susceptibility, DFT, and single-crystal EPR.

    PubMed

    Venegas-Yazigi, Diego; Spodine, Evgenia; Saldias, Marianela; Vega, Andrés; Paredes-García, Verónica; Calvo, Rafael; de Santana, Ricardo Costa

    2015-04-20

    We report the crystal face indexing and molecular spatial orientation, magnetic properties, electron paramagnetic resonance (EPR) spectra, and density functional theory (DFT) calculations of two previously reported oxovanadium phosphates functionalized with Cu(II) complexes, namely, [Cu(bipy)(VO2)(PO4)]n (1) and [{Cu(phen)}2(VO2(H2O)2)(H2PO4)2 (PO4)]n (2), where bipy = 2,2'-bipyridine and phen = 1,10-phenanthroline, obtained by a new synthetic route allowing the growth of single crystals appropriate for the EPR measurements. Compounds 1 and 2 crystallize in the triclinic group P1̅ and in the orthorhombic Pccn group, respectively, containing dinuclear copper units connected by two -O-P-O- bridges in 1 and by a single -O-P-O- bridge in 2, further connected through -O-P-O-V-O- bridges. We emphasize in our work the structural aspects related to the chemical paths that determine the magnetic properties. Magnetic susceptibility data indicate bulk antiferromagnetism for both compounds, allowing to calculate J = -43.0 cm(-1) (dCu-Cu = 5.07 Å; J defined as Hex(i,j) = -J Si·Sj), considering dinuclear units for 1, and J = -1.44 cm(-1) (dCu-Cu = 3.47 Å) using the molecular field approximation for 2. The single-crystal EPR study allows evaluation of the g matrices, which provide a better understanding of the electronic structure. The absence of structure of the EPR spectra arising from the dinuclear character of the compounds allows estimation of weak additional exchange couplings |J'| > 0.3 cm(-1) for 1 (dCu-Cu = 5.54 Å) and a smaller value of |J'| ≥ 0.15 cm(-1) for 2 (dCu-Cu = 6.59 Å). DFT calculations allow evaluating two different exchange couplings for each compound, specifically, J = -36.60 cm(-1) (dCu-Cu = 5.07 Å) and J' = 0.20 cm(-1) (dCu-Cu =5.54 Å) for 1 and J = -1.10 cm(-1) (dCu-Cu =3.47 Å) and J' = 0.01 cm(-1) (dCu-Cu = 6.59 Å) for 2, this last value being in the range of the uncertainties of the calculations. Thus, these values are in good agreement

  15. Photochemistry in photonic crystal fiber nanoreactors.

    PubMed

    Chen, Jocelyn S Y; Euser, Tijmen G; Farrer, Nicola J; Sadler, Peter J; Scharrer, Michael; Russell, Philip St J

    2010-05-17

    We report the use of a liquid-filled hollow-core photonic crystal fiber (PCF) as a highly controlled photochemical reactor. Hollow-core PCFs have several major advantages over conventional sample cells: the sample volume per optical path length is very small (2.8 nL cm(-1) in the fiber used), long optical path lengths are possible as a result of very low intrinsic waveguide loss, and furthermore the light travels in a diffractionless single mode with a constant transverse intensity profile. As a proof of principle, the (very low) quantum yield of the photochemical conversion of vitamin B(12), cyanocobalamin (CNCbl) to hydroxocobalamin ([H(2)OCbl](+)) in aqueous solution was measured for several pH values from 2.5 to 7.5. The dynamics of the actively induced reaction were monitored in real-time by broadband absorption spectroscopy. The PCF nanoreactor required ten thousand times less sample volume compared to conventional techniques. Furthermore, the enhanced sensitivity and optical pump intensity implied that even systems with very small quantum yields can be measured very quickly--in our experiments one thousand times faster than in a conventional cuvette. PMID:20391563

  16. Optics in Microstructured and Photonic Crystal Fibers

    NASA Astrophysics Data System (ADS)

    Knight, J. C.

    2008-10-01

    The development of optical fibers with two-dimensional patterns of air holes running down their length has reinvigorated research in the field of fiber optics. It has greatly—and fundamentally—broadened the range of specialty optical fibers, by demonstrating that optical fibers can be more "special" than previously thought. Fibers with air cores have made it possible to deliver energetic femtosecond-scale optical pulses, transform limited, as solitons, using single-mode fiber. Other fibers with anomalous dispersion at visible wavelengths have spawned a new generation of single-mode optical supercontinuum sources, spanning visible and near-infrared wavelengths and based on compact pump sources. A third example is in the field of fiber lasers, where the use of photonic crystal fiber concepts has led to a new hybrid laser technology, in which the very high numerical aperture available sing air holes have enabled fibers so short they are more naturally held straight than bent. This paper describes some of the basic physics and technology behind these developments, illustrated with some of the impressive demonstrations of the past 18 months.

  17. Topological Z2 Gapless Photonic Crystals

    NASA Astrophysics Data System (ADS)

    Xie, Biye; Wang, Zidan

    Topological properties of electronic materials with gapless band structure such as Topological Semimetals(TSMs) and Topological Metals(TMs) have drew lots of attention to both theoretical and experimental physicists recently. Although theoretical prediction of TSMs and TMs have been done well, experimental study of them is quite difficult to perform due to the fact that it is very difficult to control and design certain electronic materials. However, since the topological properties stem from the geometric feature, we can study them in Photonic Crystals(PhCs) which are much easy to be controlled and designed. Here we study 2-dimension PhCs consisting of gyrotropic materials with hexagonal structure. In the Brillouin corner, the dispersion relation has gapless points which are similar to Dirac Cones in electronic materials. We firstly derive the effective Hamiltonian of this system and show that if certain perturbation is added to this effective Hamiltonian, this system belongs to AII class according to Altland and Zirbauer topological classification and is described by a Z2 topological charge. Finally we also propose a way to detect this Z2 topological charge using momentum space Aharonov-Bohm interferometer which is firstly proposed by L.Duca and T.Li,etc.

  18. A leap over Dirac cones in one-dimensional graphene-based photonic crystal

    NASA Astrophysics Data System (ADS)

    Jahani, D.; Abaspour, L.; Soltani-Vala, A.; Barvestani, J.

    2016-06-01

    The existence of a photonic bandgap in the visible range of light spectrum corresponding to a 1D graphene-based photonic crystal which recently has been proposed and is formed by embedding alternatively graphene layers into a dielectric background is investigated in this paper. By the use of the complete form of optical conductivity for the full expression of the tight-binding Hamiltonian of graphene layer, we numerically demonstrate an appeared bandgap in the visible region of the spectrum which can open up new route for further high-frequency applications of graphene-based photonic devices. It is revealed that the associated bandgap could be altered by changing the hopping energy and the amount of chemical potential leading to broadening the forbidden frequency regions with further increasing. Finally, it is also shown that the tunability feature of the photonic bandgap could be affected by changing the hopping energy.

  19. Tunable complete photonic band gap in anisotropic photonic crystal slabs with non-circular air holes using liquid crystals

    NASA Astrophysics Data System (ADS)

    Fathollahi Khalkhali, T.; Bananej, A.

    2016-06-01

    In this study, we analyze the tunability of complete photonic band gap of square and triangular photonic crystal slabs composed of square and hexagonal air holes in anisotropic tellurium background with SiO2 as cladding material. The non-circular holes are infiltrated with liquid crystal. Using the supercell method based on plane wave expansion, we study the variation of complete band gap by changing the optical axis orientation of liquid crystal. Our numerical results show that noticeable tunability of complete photonic band gap can be obtained in both square and triangular structures with non-circular holes.

  20. Two-pattern compound photonic crystals with a large complete photonic band gap

    SciTech Connect

    Jia Lin; Thomas, Edwin L.

    2011-09-15

    We present a set of two-dimensional aperiodic structures with a large complete photonic band gap (PBG), which are named two-pattern photonic crystals. By superposing two substructures without regard to registration, we designed six new aperiodic PBG structures having a complete PBG larger than 15% for {epsilon}{sub 2}/{epsilon}{sub 1} = 11.4. The rod-honeycomb two-pattern photonic crystal provides the largest complete PBG to date. An aperiodic structure becomes the champion structure with the largest PBG. Surprisingly, the TM and TE gaps of a two-pattern photonic crystal are much less interdependent than the PBGs of conventional photonic crystals proposed before, affording interesting capabilities for us to tune the TM and TE PBGs separately. By altering the respective substructures, optical devices for different polarizations (TE, TM, or both) can readily be designed.

  1. Photonic Crystal and Photonic Band-Gap Structures for Light Extraction and Emission Control

    NASA Astrophysics Data System (ADS)

    de La Rue, Richard M.

    Research into photonic crystal (PhC) and photonic band-gap (PBG) structures has been motivated, from the start, by their possible use in controlling, modifying and enhancing the light emission process from high refractive index solid materials. This chapter considers the possible role of such structures when incorporated into semiconductor diode based light-emitting devices. Both light-emitting diodes (LEDs) and lasers will be considered. In order to provide a proper framework for discussion and analysis, space is devoted to the historical development of III-V semiconductor based LEDs — and to competing alternative approaches that have been demonstrated for enhanced light extraction. The possible advantages of photonic quasi-crystal (PQC) structures over regularly periodic photon crystal structures for advanced LED designs are also considered. Photonic crystal structures potentially provide major enhancements in the performance of laser diodes (LDs) — and progress towards this performance enhancement will be reviewed.

  2. Achieving omnidirectional photonic band gap in sputter deposited TiO{sub 2}/SiO{sub 2} one dimensional photonic crystal

    SciTech Connect

    Jena, S. Tokas, R. B.; Sarkar, P.; Thakur, S.; Sahoo, N. K.; Haque, S. Maidul; Misal, J. S.; Rao, K. D.

    2015-06-24

    The multilayer structure of TiO{sub 2}/SiO{sub 2} (11 layers) as one dimensional photonic crystal (1D PC) has been designed and then fabricated by using asymmetric bipolar pulse DC magnetron sputtering technique for omnidirectional photonic band gap. The experimentally measured photonic band gap (PBG) in the visible region is well matched with the theoretically calculated band structure (ω vs. k) diagram. The experimentally measured omnidirectional reflection band of 44 nm over the incident angle range of 0°-70° is found almost matching within the theoretically calculated band.

  3. Pendellösung effect in photonic crystals

    NASA Astrophysics Data System (ADS)

    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.

  4. An approach to control tuning range and speed in 1D ternary photonic band gap material nano-layered optical filter structures electro-optically

    NASA Astrophysics Data System (ADS)

    Zia, Shahneel; Banerjee, Anirudh

    2016-05-01

    This paper demonstrates a way to control spectrum tuning capability in one-dimensional (1D) ternary photonic band gap (PBG) material nano-layered structures electro-optically. It is shown that not only tuning range, but also tuning speed of tunable optical filters based on 1D ternary PBG structures can be controlled Electro-optically. This approach finds application in tuning range enhancement of 1D Ternary PBG structures and compensating temperature sensitive transmission spectrum shift in 1D Ternary PBG structures.

  5. Photonic crystals for improving light absorption in organic solar cells

    SciTech Connect

    Duché, D. Le Rouzo, J.; Masclaux, C.; Gourgon, C.

    2015-02-07

    We theoretically and experimentally study the structuration of organic solar cells in the shape of photonic crystal slabs. By taking advantage of the optical properties of photonic crystals slabs, we show the possibility to couple Bloch modes with very low group velocities in the active layer of the cells. These Bloch modes, also called slow Bloch modes (SBMs), allow increasing the lifetime of photons within the active layer. Finally, we present experimental demonstration performed by using nanoimprint to directly pattern the standard poly-3-hexylthiophène:[6,6]-phenyl-C61-butiryc acid methyl ester organic semiconductor blend in thin film form in the shape of a photonic crystal able to couple SBMs. In agreement with the model, optical characterizations will demonstrate significant photonic absorption gains.

  6. Optimizing polarization-diversity couplers for Si-photonics: reaching the -1dB coupling efficiency threshold.

    PubMed

    Carroll, Lee; Gerace, Dario; Cristiani, Ilaria; Andreani, Lucio C

    2014-06-16

    Polarization-diversity couplers are low-cost industrially-scalable passive devices that can couple light of unknown polarization from a telecom fiber-mode to a pair of TE-polarized wave-guided modes in the Silicon-on-Insulator platform. These couplers offer significantly more relaxed alignment tolerances than edge-coupling schemes, which is advantageous for commercial fiber-packaging of Si-photonic circuits. However, until now, polarization-diversity couplers have not offered sufficient coupling efficiency to motivate serious commercial consideration. Using 3D finite difference time domain calculations for device optimization, we identify Silicon-on-Insulator polarization-diversity couplers with 1,550 nm coupling efficiencies of -0.95 dB and -1.9 dB, for designs with and without bottom-reflector elements, respectively. These designs offer a significant improvement over state-of-the-art performance, and effectively bridge the "performance gap" between polarization-diversity couplers and 1D-grating couplers. Our best polarization-diversity coupler design goes beyond the -1dB efficiency limit that is typically accepted as the minimum needed for industrial adoption of coupler devices in the telecoms market. PMID:24977572

  7. Imaging of Protein Crystals with Two-Photon Microscopy

    SciTech Connect

    Padayatti, Pius; Palczewska, Grazyna; Sun, Wenyu; Palczewski, Krzysztof; Salom, David

    2012-05-02

    Second-order nonlinear optical imaging of chiral crystals (SONICC), which portrays second-harmonic generation (SHG) by noncentrosymmetric crystals, is emerging as a powerful imaging technique for protein crystals in media opaque to visible light because of its high signal-to-noise ratio. Here we report the incorporation of both SONICC and two-photon excited fluorescence (TPEF) into one imaging system that allows visualization of crystals as small as 10 {mu}m in their longest dimension. Using this system, we then documented an inverse correlation between the level of symmetry in examined crystals and the intensity of their SHG. Moreover, because of blue-green TPEF exhibited by most tested protein crystals, we also could identify and image SHG-silent protein crystals. Our experimental data suggest that the TPEF in protein crystals is mainly caused by the oxidation of tryptophan residues. Additionally, we found that unspecific fluorescent dyes are able to bind to lysozyme crystals and enhance their detection by TPEF. We finally confirmed that the observed fluorescence was generated by a two-photon rather than a three-photon process. The capability for imaging small protein crystals in turbid or opaque media with nondamaging infrared light in a single system makes the combination of SHG and intrinsic visible TPEF a powerful tool for nondestructive protein crystal identification and characterization during crystallization trials.

  8. Imaging of protein crystals with two–photon microscopy†

    PubMed Central

    Padayatti, Pius; Palczewska, Grazyna; Sun, Wenyu; Palczewski, Krzysztof; Salom, David

    2012-01-01

    Second–order non–linear optical imaging of chiral crystals (SONICC), that portrays second harmonic generation (SHG) by non–centrosymmetric crystals, is emerging as a powerful imaging technique for protein crystals in media opaque to visible light because of its high signal–to–noise ratio. Here we report the incorporation of both SONICC and two–photon excited fluorescence (TPEF) into one imaging system that allows visualization of crystals as small as ~10 μm in their longest dimension. Using this system, we then documented an inverse correlation between the level of symmetry in examined crystals and the intensity of their SHG. Moreover, because of blue-green TPEF exhibited by most tested protein crystals, we also could identify and image SHG–silent protein crystals. Our experimental data suggests that the TPEF in protein crystals is mainly caused by the oxidation of tryptophan residues. Additionally, we found that unspecific fluorescent dyes are able to bind to lysozyme crystals and enhance their detection by TPFE. We finally confirmed that the observed fluorescence was generated by a two-photon rather than a three-photon process. The capability for imaging small protein crystals in turbid or opaque media with non–damaging infrared light in a single system, makes the combination of SHG and intrinsic visible TPEF a powerful tool for non–destructive protein crystal identification and characterization during crystallization trials. PMID:22324807

  9. The research on a photonic-crystal fiber sensor

    NASA Astrophysics Data System (ADS)

    Peng, Yong; Cheng, Yi

    2009-07-01

    To study the photonic-crystal fiber applied in the chemical sensor, the photonic-crystal fiber was used as transmission medium. With Sol-Gel method, we selective coated thin film containing fluorescent probe in the photonic-crystal fiber core, then attained an excellent photonic-crystal fiber acetylcholinesterase sensor. The sensor could be applied in biological / chemical research, clinical medicine, environmental protection, food inspection, biochemical preventive war field and so on. In organophosphorus pesticide residue testing, the experimental results indicated that the linear measurement range could arrive to 1×10-9~ 1×10-3 mol/L, moreover the detection limit is 1×10-10 mol/L.

  10. Enhanced spontaneous Raman scattering using a photonic crystal fiber

    SciTech Connect

    Buric, M.P.; Falk, J.; Chen, K.; Woodruff, S.D.

    2008-07-22

    The output power from spontaneous gas-phase Raman scattering is enhanced using a hollow-core photonic crystal fiber for the gas cell and Stokes light collector, yielding >100 times enhancement over a free-space configuration.

  11. Enhanced Spontaneous Raman Scattering using a Photonic Crystal Fiber

    SciTech Connect

    M.P. Buric; J. Fal; K. Chen; S. Woodruff1

    2007-10-01

    The output power from spontaneous gas-phase Raman scattering is enhanced using a hollow-core photonic crystal fiber for the gas cell and Stokes light collector, yielding >100 times enhancement over a free-space configuration.

  12. Photonic-crystal time-domain simulations using Wannier functions.

    PubMed

    Blum, Christian; Wolff, Christian; Busch, Kurt

    2011-01-15

    We present a Wannier-function-based time-domain method for photonic-crystal integrated optical circuits. In contrast to other approaches, this method allows one to trade CPU time against memory consumption and therefore is particularly well suited for the treatment of large-scale systems. As an illustration, we apply the method to the design of a photonic-crystal-based sensor, which utilizes a dual Mach-Zehnder-Fano interferometer. PMID:21263535

  13. Use of a photonic crystal for optical amplifier gain control

    DOEpatents

    Lin, Shawn-Yu; Fleming, James G.; El-Kady, Ihab

    2006-07-18

    An optical amplifier having a uniform gain profile uses a photonic crystal to tune the density-of-states of a gain medium so as to modify the light emission rate between atomic states. The density-of-states of the gain medium is tuned by selecting the size, shape, dielectric constant, and spacing of a plurality of microcavity defects in the photonic crystal. The optical amplifier is particularly useful for the regeneration of DWDM signals in long optical fibers.

  14. Measurements of HB photonic crystal fibers with low temperature sensitivity

    NASA Astrophysics Data System (ADS)

    Makara, Mariusz; Wojcik, Jan; Mergo, Pawel; Klimek, Jacek; Skorupski, Krzysztof; Kopeć, Jarosław

    2008-06-01

    We report on experimental studies of phase and group modal birefringence vs. temperature in two highly birefringent (HB) photonic crystal fibers, in which birefringence is caused by filling factor asymmetry. The sensitivity measurements were carried out at two wavelengths 633 and 834 nm. Our results show that temperature sensitivity in the HB photonic crystal fibers is two orders smaller then in traditional HB fibers. Simultaneously, our results exhibit weak dependence of group modal birefringence on temperature.

  15. Two-photon absorption in Hg 2Cl 2 crystals

    NASA Astrophysics Data System (ADS)

    Pelant, I.; Ambrož, M.; Hála, J.; Kohlová, V.; Barta, Č.

    1985-01-01

    Violet luminescence (396 nm) of Hg 2Cl 2 single crystals was observed under excitation of green light (∼ 500 nm) of a pulsed dye laser at liquid helium temperature. The effect is interpreted as due to the two-photon absorption process. The two-photon excitation spectrum of the luminescence was measured in the wavelength range 475-530 nm. Possible mechanisms of the two-photon transition are outlined.

  16. Polarisation singularities in photonic crystals for an on-chip spin-photon interface

    NASA Astrophysics Data System (ADS)

    Beggs, Daryl M.; Young, Andrew B.; Thijssen, Arthur C. T.; Oulton, Ruth

    2015-03-01

    Integrated quantum photonic chips are a leading contender for future quantum technologies, which aim to use the entanglement and superposition properties of quantum physics to speed up the manipulation of data. Quantum information may be stored and transmitted in photons, which make excellent flying qubits. Photons suffer little from decoherence, and single qubit gates performed by changing photon phase, are straightforward. Less straightforward is the ability to create two qubit gates, where one photon is used to switch another's state; inherently difficult due to the extremely small interaction cross-section between photons. The required deterministic two-qubit interactions will likely need a hybrid scheme with the ``flying'' photonic qubit interacting with a ``static'' matter qubit. Here we present the design of a photonic crystal waveguide structure that can couple electron-spin to photon path, thus providing an interface between a static and a flying qubit. We will show that the complex polarization properties inherent in the photonic crystal eigenmodes supports polarization singularities - positions in the electric field vector where one of the parameters describing the local polarization ellipse is singular - and that these singularities are ideal for a range of quantum information applications. In particular, we will show that by placing a quantum dot at one of these singularities, the electron-spin becomes correlated with the photon emission direction, creating an in-plane spin-photon interface that can transfer quantum information from static to flying qubits.

  17. Alignment of crystal orientations of the multi-domain photonic crystals in Parides sesostris wing scales.

    PubMed

    Yoshioka, S; Fujita, H; Kinoshita, S; Matsuhana, B

    2014-03-01

    It is known that the wing scales of the emerald-patched cattleheart butterfly, Parides sesostris, contain gyroid-type photonic crystals, which produce a green structural colour. However, the photonic crystal is not a single crystal that spreads over the entire scale, but it is separated into many small domains with different crystal orientations. As a photonic crystal generally has band gaps at different frequencies depending on the direction of light propagation, it seems mysterious that the scale is observed to be uniformly green under an optical microscope despite the multi-domain structure. In this study, we have carefully investigated the structure of the wing scale and discovered that the crystal orientations of different domains are not perfectly random, but there is a preferred crystal orientation that is aligned along the surface normal of the scale. This finding suggests that there is an additional factor during the developmental process of the microstructure that regulates the crystal orientation. PMID:24352678

  18. Alignment of crystal orientations of the multi-domain photonic crystals in Parides sesostris wing scales

    PubMed Central

    Yoshioka, S.; Fujita, H.; Kinoshita, S.; Matsuhana, B.

    2014-01-01

    It is known that the wing scales of the emerald-patched cattleheart butterfly, Parides sesostris, contain gyroid-type photonic crystals, which produce a green structural colour. However, the photonic crystal is not a single crystal that spreads over the entire scale, but it is separated into many small domains with different crystal orientations. As a photonic crystal generally has band gaps at different frequencies depending on the direction of light propagation, it seems mysterious that the scale is observed to be uniformly green under an optical microscope despite the multi-domain structure. In this study, we have carefully investigated the structure of the wing scale and discovered that the crystal orientations of different domains are not perfectly random, but there is a preferred crystal orientation that is aligned along the surface normal of the scale. This finding suggests that there is an additional factor during the developmental process of the microstructure that regulates the crystal orientation. PMID:24352678

  19. Photonic crystals, light manipulation, and imaging in complex nematic structures

    NASA Astrophysics Data System (ADS)

    Ravnik, Miha; Å timulak, Mitja; Mur, Urban; Čančula, Miha; Čopar, Simon; Žumer, Slobodan

    2016-03-01

    Three selected approaches for manipulation of light by complex nematic colloidal and non-colloidal structures are presented using different own custom developed theoretical and modelling approaches. Photonic crystals bands of distorted cholesteric liquid crystal helix and of nematic colloidal opals are presented, also revealing distinct photonic modes and density of states. Light propagation along half-integer nematic disclinations is shown with changes in the light polarization of various winding numbers. As third, simulated light transmission polarization micrographs of nematic torons are shown, offering a new insight into the complex structure characterization. Finally, this work is a contribution towards using complex soft matter in optics and photonics for advanced light manipulation.

  20. Chalcogenide glass-based three-dimensional photonic crystals

    NASA Astrophysics Data System (ADS)

    Feigel, A.; Kotler, Z.; Sfez, B.; Arsh, A.; Klebanov, M.; Lyubin, V.

    2000-11-01

    AsSeTe chalcogenide glasses are materials that are photosensitive and have a large refractive index. These properties make these glasses particularly suitable for the fabrication of photonic crystals. We present a way to build three-dimensional photonic structures from chalcogenide glasses using vapor deposition and direct holographic writing. We show that this technique is intrinsically self-aligned, providing a simple way to build layer-by-layer photonic crystals and a four-layer structure demonstrating the principle of the technique.

  1. Controllable light diffraction in woodpile photonic crystals filled with liquid crystal

    SciTech Connect

    Ho, Chih-Hua; Zeng, Hao; Wiersma, Diederik S.; Cheng, Yu-Chieh; Maigyte, Lina; Trull, Jose; Cojocaru, Crina; Staliunas, Kestutis

    2015-01-12

    An approach to switching between different patterns of light beams transmitted through the woodpile photonic crystals filled with liquid crystals is proposed. The phase transition between the nematic and isotropic liquid crystal states leads to an observable variation of the spatial pattern transmitted through the photonic structure. The transmission profiles in the nematic phase also show polarization sensibility due to refractive index dependence on the field polarization. The experimental results are consistent with a numerical calculation by Finite Difference Time Domain method.

  2. Manipulating light propagation and emission using photonic crystals

    SciTech Connect

    Nair, Rajesh V.; Jagatap, B. N.

    2014-03-31

    We discuss the synthesis and characterization of self-assembled photonic crystals using polymer colloids having sub-micron diameters. The angle resolved optical reflectivity measurements indicate the hybridization between stop gaps in the multiple Bragg diffraction regimes. Each diffraction resonances in the multiple Bragg diffraction regimes are assigned to respective crystal planes. We also discuss laser-induced studies of spontaneous emission in self-assembled photonic crystals having Rhodamine-B dye doped colloids. Our experimental results reveal more than 51% inhibition in emission intensity within the stop gap as compared to a proper reference sample.

  3. Three dimensional silicon photonic crystals fabricated by two photon phase mask lithography.

    SciTech Connect

    Wiltzius, P.; Braun, P. V.; Liao, H.; Brzezinski, A.; Chen, Y. C.; Nelson, E.; Shir, D.; Rogers, J. A.; Bogart, Katherine Huderle Andersen

    2008-08-01

    We describe the fabrication of silicon three dimensional photonic crystals using polymer templates defined by a single step, two-photon exposure through a layer of photopolymer with relief molded on its surface. The resulting crystals exhibit high structural quality over large areas, displaying geometries consistent with calculation. Spectroscopic measurements of transmission and reflection through the silicon and polymer structures reveal excellent optical properties, approaching properties predicted by simulations that assume ideal layouts.

  4. Photon Cascade from a Single Crystal Phase Nanowire Quantum Dot.

    PubMed

    Bouwes Bavinck, Maaike; Jöns, Klaus D; Zieliński, Michal; Patriarche, Gilles; Harmand, Jean-Christophe; Akopian, Nika; Zwiller, Val

    2016-02-10

    We report the first comprehensive experimental and theoretical study of the optical properties of single crystal phase quantum dots in InP nanowires. Crystal phase quantum dots are defined by a transition in the crystallographic lattice between zinc blende and wurtzite segments and therefore offer unprecedented potential to be controlled with atomic layer accuracy without random alloying. We show for the first time that crystal phase quantum dots are a source of pure single-photons and cascaded photon-pairs from type II transitions with excellent optical properties in terms of intensity and line width. We notice that the emission spectra consist often of two peaks close in energy, which we explain with a comprehensive theory showing that the symmetry of the system plays a crucial role for the hole levels forming hybridized orbitals. Our results state that crystal phase quantum dots have promising quantum optical properties for single photon application and quantum optics. PMID:26806321

  5. Tunable optical anisotropy in three-dimensional photonic crystals

    SciTech Connect

    Che Ming; Li Zhiyuan; Liu Rongjuan

    2007-08-15

    Artificial optical birefringence can be realized in three-dimensional photonic crystals with a uniaxial structural symmetry: e.g., woodpile photonic crystals with a tetragonal lattice structure in the long-wavelength limit. The ordinary and extraordinary indices of refraction are determined from calculation of the reflection coefficient for a plane wave incident on the surface of a semi-infinite photonic crystal at different angles. We find that the anisotropy can be widely tuned by simply changing the width and thickness of the dielectric rod. A large relative negative anisotropy over 33% is found. A transition from positive anisotropy to negative anisotropy can be readily achieved. At certain parameters, a structurally anisotropic nanostructure can behave like an optically isotropic medium. Our study opens a window to use artificial nanostructures to create an arbitrary optical anisotropy that is not possible in natural crystals.

  6. Gigahertz Modulation of a Photonic Crystal Cavity

    NASA Astrophysics Data System (ADS)

    Ali, Aaron Karim Taylor

    Photonic crystal (PtC) cavities are an increasingly important way to create all optical methods to control optical data. Not only must the data be controlled, but interfacing it with high frequency electrical signals is particularly interesting especially if this occurs in the 1.55microm telecom band. We present an experiment that uses Rayleigh surface acoustic waves (SAWs) to modulate the frequency of the guided mode of an L3-cavity PtC created on a silicon slab. This work has the potential to interface optical and electrical signals via a mechanical strain wave operating at gigahertz frequencies. Defects are carefully designed into a triangular lattice PtC to realize a waveguide coupled optical cavity. The cavity can be experimentally accessed through grating couplers excited by polarized light at 10° incidence from normal. The optical components are fabricated on a silicon-on-insulator platform, with light confined to the silicon slab region. Through transmission experiments, the L3 cavity was found to have a narrow resonance characterized by a Lorentzian distribution. A quality factor of 165 centered at 6255cm --1 (1.599microm) was measured. Aluminum interdigitated transducers (IDTs) were fabricated through a lithography liftoff process. Their ability to create SAWs requires a piezoelectric medium. As silicon does not have this property, growth of a thin ZnO film was required. The transducers were measured using a network analyzer and were found to produce Rayleigh SAWs at a frequency of 179MHz and a wavelength of 24microm. The acoustic energy traveled 70microm to the target optical device. The L3 cavity has dimensions of around 4microm a side - less than 1/2 a SAW wavelength. Modulation of the L3 PtC resonant frequency was monitored through a repeat of the transmission experiment but with RF excitation of the IDTs at the SAW frequency. A broadening of the transmission spectrum was expected. Unfortunately no change in the fitting parameters could be measured

  7. Controlling single-photon transport with three-level quantum dots in photonic crystals

    NASA Astrophysics Data System (ADS)

    Yan, Cong-Hua; Jia, Wen-Zhi; Wei, Lian-Fu

    2014-03-01

    We investigate how to control single-photon transport along the photonic crystal waveguide with the recent experimentally demonstrated artificial atoms [i.e., Λ-type quantum dots (QDs)] [S. G. Carter et al., Nat. Photon. 7, 329 (2013), 10.1038/nphoton.2013.41] in an all-optical way. Adopting full quantum theory in real space, we analytically calculate the transport coefficients of single photons scattered by a Λ-type QD embedded in single- and two-mode photonic crystal cavities (PCCs), respectively. Our numerical results clearly show that the photonic transmission properties can be exactly manipulated by adjusting the coupling strengths of waveguide-cavity and QD-cavity interactions. Specifically, for the PCC with two degenerate orthogonal polarization modes coupled to a Λ-type QD with two degenerate ground states, we find that the photonic transmission spectra show three Rabi-splitting dips and the present system could serve as single-photon polarization beam splitters. The feasibility of our proposal with the current photonic crystal technique is also discussed.

  8. A study of optical reflectance and localization modes of 1-D Fibonacci photonic quasicrystals using different graded dielectric materials

    NASA Astrophysics Data System (ADS)

    Singh, Bipin K.; Pandey, Praveen C.

    2014-06-01

    In this paper, we present an analytical study on the reflection properties of light through one-dimensional (1-D) quasi-periodic multilayer structures. The considered structures are as follows: F7, F8, F9, (F2)10, (F3)10 and some combinations such as: [(F2)10 (F7) (F2)10], [(F2)10 (F8) (F2)10], [(F3)10 (F7) (F3)10], [(F3)10 (F8) (F3)10], [(F2)10(F3)10], [(F2)10 (F7) (F3)10] and [(F2)10 (F8) (F3)10], where (Fj)n represents n period of the Fibonacci sequence of jth generation. These multilayer structures are considered of two types of layers. One type of layer is considered of graded material like normal, linear or exponential graded material, and the second type of layer is considered of constant refractive index material. Transfer matrix method is utilized to calculate the reflection spectra and localization modes of such structures in the frequency range 150-450 THz. This work would provide the basis of understanding of the effect of graded materials on the reflection and localization modes in Fibonacci photonic quasicrystal structures and obtained spectra can be used in the recognition of grading of materials. The considered heterostructures provide the broad reflection band and some localization modes in the calculated region.

  9. Photon-dressed quasiparticle states in 1D and 2D materials: a many-body Floquet approach

    NASA Astrophysics Data System (ADS)

    Manghi, Franca; Puviani, Matteo

    We studiy the interplay between electron-electron interactions and non-equilibrium conditions associated to time-dependent external fields. Exploring phases of quantum matter away from equilibrium may give access to regimes inaccessible under equilibrium conditions. What makes this field particularly interesting is the possibility to engineer new phases of matter by an external tunable control. We have developed a scheme that allows to treat photo-induced phenomena in the presence of electron-electron many body interactions, where both the nonlinear effects of the external field and the electron-electron correlation are treated simultaneously and in a non-perturbative way. The Floquet approach is used to include the effects of the external time periodic field, and the Cluster Perturbation Theory to describe interacting electrons in a lattice. They are merged in a Floquet-Green function method that allows to calculate photon dressed quasiparticle excitation. For 1D systems we show that an unconventional Mott insulator-to-metal transition occurs for given characteristics of the applied field (intensity and frequency). The method has also been applied to the 2D honeycomb lattice (graphene), where in the presence of realistic values of electron-electron interaction, we show that linearly polarized light may give rise to non-dissipative edge states associated to a non-trivial topological behavior.

  10. Fabrication and characterization of three-dimensional infrared photonic crystals

    NASA Astrophysics Data System (ADS)

    Zavieh, Lisa

    It has been predicted theoretically that photonic crystals can be used to control the propagation of light through dielectric media for wavelengths extending beyond the microwave to include the infrared and the visible. Fabrication of 3-D photonic crystals with a bandgap in the near infrared or visible would have application in the design of a new class of photonic devices that include optical mirrors, waveguides, and cavity resonators. Demonstrations of 3-D photonic crystals have been limited primarily to the microwave and infrared wavelength regimes because of the constraints imposed by the nanometer scale dimensions required for operation in the visible. This thesis presents a novel method of fabricating a simple cubic photonic crystal which potentially can be tailored to operate at any wavelength. Fabrication was broken down into several processing steps, each of which was investigated independently. Design of Experiment (DOE) was used in a parametric study to optimize dry etching conditions by which GaAs/AlxGa1--x As multilayer structures were etched with anisotropic profile and rapid etch rate. Also, the etching properties of diffusion controlled wet lateral etching of buried AlxGa1--xAs layers in hydrofluoric acid solutions (HF) were investigated. Using the results obtained from the etching studies, both dry and wet etching techniques were employed to fabricate the simple-cubic photonic structure. Following fabrication, the photonic crystal was characterized at normal angles and oblique incidence using Fourier transform infrared spectroscopy (FTIR). The experimental results show strong correlation to theoretically predicted values. The simplicity of the process and positive results indicate that it may be possible to scale down the structure to obtain an photonic band lattice with a bandgap of 1.55 mum.