Showing papers on "Photonic crystal published in 1999"
Proceedings Article•
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TL;DR: In this paper, the authors describe photonic crystals as the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures, and the interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.
Abstract: The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.
2,722 citations
TL;DR: A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated and pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.
Abstract: A laser cavity formed from a single defect in a two-dimensional photonic crystal is demonstrated. The optical microcavity consists of a half wavelength–thick waveguide for vertical confinement and a two-dimensional photonic crystal mirror for lateral localization. A defect in the photonic crystal is introduced to trap photons inside a volume of 2.5 cubic half-wavelengths, approximately 0.03 cubic micrometers. The laser is fabricated in the indium gallium arsenic phosphide material system, and optical gain is provided by strained quantum wells designed for a peak emission wavelength of 1.55 micrometers at room temperature. Pulsed lasing action has been observed at a wavelength of 1.5 micrometers from optically pumped devices with a substrate temperature of 143 kelvin.
2,310 citations
TL;DR: The confinement of light within a hollow core (a large air hole) in a silica-air photonic crystal fiber is demonstrated and certain wavelength bands are confined and guided down the fiber.
Abstract: The confinement of light within a hollow core (a large air hole) in a silica-air photonic crystal fiber is demonstrated Only certain wavelength bands are confined and guided down the fiber, each band corresponding to the presence of a full two-dimensional band gap in the photonic crystal cladding Single-mode vacuum waveguides have a multitude of potential applications from ultrahigh-power transmission to the guiding of cold atoms
1,935 citations
TL;DR: The relations for the dispersion and the group velocity of the photonic band of the CROW's are obtained and it is found that they are solely characterized by coupling factor k(1) .
Abstract: We propose a new type of optical waveguide that consists of a sequence of coupled high- Q resonators. Unlike other types of optical waveguide, waveguiding in the coupled-resonator optical waveguide (CROW) is achieved through weak coupling between otherwise localized high- Q optical cavities. Employing a formalism similar to the tight-binding method in solid-state physics, we obtain the relations for the dispersion and the group velocity of the photonic band of the CROW's and find that they are solely characterized by coupling factor k 1 . We also demonstrate the possibility of highly efficient nonlinear optical frequency conversion and perfect transmission through bends in CROW's.
1,671 citations
TL;DR: In this paper, the properties of two-dimensional periodic dielectric structures that have a band gap for propagation in a plane and that use index guiding to confine light in the third dimension are analyzed.
Abstract: We analyze the properties of two-dimensionally periodic dielectric structures that have a band gap for propagation in a plane and that use index guiding to confine light in the third dimension. Such structures are more amenable to fabrication than photonic crystals with full three-dimensional band gaps, but retain or approximate many of the latter's desirable properties. We show how traditional band-structure analysis can be adapted to slab systems in the context of several representative structures, and describe the unique features that arise in this framework compared to ordinary photonic crystals.
1,091 citations
TL;DR: In this article, the photonic bandgap (PBG) structure for microwave integrated circuits is presented, which is a two-dimensional square lattice with each element consisting of a metal pad and four connecting branches.
Abstract: This paper presents a novel photonic bandgap (PBG) structure for microwave integrated circuits. This new PBG structure is a two-dimensional square lattice with each element consisting of a metal pad and four connecting branches. Experimental results of a microstrip on a substrate with the PEG ground plane displays a broad stopband, as predicted by finite-difference time-domain simulations. Due to the slow-wave effect generated by this unique structure, the period of the PBG lattice is only 0.1/spl lambda//sub 0/ at the cutoff frequency, resulting in the most compact PEG lattice ever achieved. In the passband, the measured slow-wave factor (/spl beta//k/sub 0/) is 1.2-2.4 times higher and insertion loss is at the same level compared to a conventional 50-/spl Omega/ line. This uniplanar compact PBG (UC-PBG) structure can be built using standard planar fabrication techniques without any modification. Several application examples have also been demonstrated, including a nonleaky conductor-backed coplanar waveguide and a compact spurious-free bandpass filter. This UC-PBG structure should find wide applications for high-performance and compact circuit components in microwave and millimeter-wave integrated circuits.
831 citations
TL;DR: In this article, an optically birefringent nematic liquid crystal is infiltrated into the void regions of an inverse opal, photonic-band-gap (PBG) material, the resulting composite material exhibits a completely tunable PBG.
Abstract: We demonstrate that when an optically birefringent nematic liquid crystal is infiltrated into the void regions of an inverse opal, photonic-band-gap (PBG) material, the resulting composite material exhibits a completely tunable PBG. In particular, the three-dimensional PBG can be completely opened or closed by applying an electric field which rotates the axis of the nematic molecules relative to the inverse opal backbone. Tunable light localization effects may be realized by controlling the orientational disorder in the nematic.
718 citations
TL;DR: In this article, self-determining collimated light is generated in a photonic crystal fabricated on silicon and the divergence of the collimated beam is insensitive to that of the incident beam and much smaller than the divergence generated in conventional Gaussian optics.
Abstract: We found that self-determining collimated light is generated in a photonic crystal fabricated on silicon. The divergence of the collimated beam is insensitive to that of the incident beam and much smaller than the divergence that would be generated in conventional Gaussian optics. The incident-angle dependence of the self-collimated light propagation including lens-like divergent propagation was interpreted in terms of the highly modulated dispersion surfaces with inflection points, where the curvature changes from downward to upward corresponding to respectively a concave/convex-lens case. This demonstration is an important step towards controlling beam profile in photonic crystal integrated light circuits and towards developing “photonic crystalline optics.”
717 citations
TL;DR: In this article, a surface-emitting laser with a two-dimensional photonic crystal structure is investigated, where the wavelength of the active layer is designed to match the folded (second-order) Γ point of the Γ−X direction.
Abstract: Lasing action of a surface-emitting laser with a two-dimensional photonic crystal structure is investigated. The photonic crystal has a triangular-lattice structure composed of InP and air holes, which is integrated with an InGaAsP/InP multiple-quantum-well active layer by a wafer fusion technique. Uniform two-dimensional lasing oscillation based on the coupling of light propagating in six equivalent Γ−X directions is successfully observed, where the wavelength of the active layer is designed to match the folded (second-order) Γ point of the Γ−X direction. The very narrow divergence angle of far field pattern and/or the lasing spectrum, which is considered to reflect the two-dimensional stop band, also indicate that the lasing oscillation occurs coherently.
668 citations
TL;DR: In this article, three-dimensional photonic crystal structures were fabricated with laser microfabrication techniques through two-photon-absorption photopolymerization of resin, and significant band-gap effects in the infrared wavelength region were observed from layer-by-layer structures.
Abstract: Three-dimensional photonic crystal structures were fabricated with laser microfabrication techniques through two-photon-absorption photopolymerization of resin. Significant band-gap effects in the infrared wavelength region were observed from “layer-by-layer” structures.
607 citations
TL;DR: In this paper, a novel type of optical waveguide, operating truly by the photonic bandgap effect, has been demonstrated, which has an improved photonic crystal cladding and a central low-index structural defect along which light is guided.
TL;DR: The aim of this review is to introduce the reader to the concepts of photonic crystals, describe the state of the art and attempt to answer the question of what uses these peculiar structures may have.
TL;DR: In this paper, a three-dimensional finite-difference time-domain analysis of localized defect modes in an optically thin dielectric slab that is patterned with a two-dimensional array of air holes is presented.
Abstract: We present a three-dimensional finite-difference time-domain analysis of localized defect modes in an optically
thin dielectric slab that is patterned with a two-dimensional array of air holes. The symmetry, quality factor, and radiation pattern of the defect modes and their dependence on the slab thickness are investigated.
TL;DR: In this article, a new class of metallic materials with long-range nano-scale ordering and hierarchical porosity was synthesized by using colloidal crystals as templates, and they were used to fabricate structures from inorganic oxides, polymers, diamond and glassy carbon.
Abstract: Colloidal crystals are ordered arrays of particles in the nanometre-to-micrometre size range. Useful microstructured materials can be created by replicating colloidal crystals in a durable matrix that preserves their key feature of long-range periodic structure1. For example, colloidal crystals have been used to fabricate structures from inorganic oxides1,2,3,4,5, polymers6,7, diamond and glassy carbon8, and semiconductor quantum dots9, and some structures have photonic properties4,8,9 or are patterned on different hierarchical length scales5. By using colloidal crystals as templates, we have synthesized a new class of metallic materials with long-range nano-scale ordering and hierarchical porosity.
TL;DR: In this paper, the authors explored the use of colloidal crystallization as a fabrication method for photonic crystals and found that the photonic behavior such as photonic band-gaps is expected only for very high index of refraction contrast systems, which can be achieved through electrodeposition of semiconductors, polymers, or metals in the interstitial space of self-assembled colloids.
Abstract: Colloidal crystallization has been explored for several years as a fabrication method for photonic crystals. While macroporous materials grown with silica or polymer colloids might exhibit pleasing opalescence, truly novel photonic behavior such as photonic band-gaps, is expected only for very high index of refraction contrast systems. This can possibly be achieved through electrodeposition of semiconductors, polymers, or metals in the interstitial space of self-assembled colloids. 2002 Elsevier Science Ltd. All rights reserved.
TL;DR: In this paper, an analysis of the operation of a new type of laser resonator with two-dimensional distributed feedback from a photonic crystal is presented, where the gain medium consists of a 2-(4-biphenylyl)-5(4-tert-butylphenyl)-1,3,4-oxadiazole host doped with Coumarin 490 and DCM and is deposited on lithographically patterned Si/SiO2 structures.
Abstract: We report an analysis of the operation of a new type of laser resonator with two-dimensional distributed feedback from a photonic crystal. The gain medium consists of a 2-(4-biphenylyl)-5(4-tert-butylphenyl)-1,3,4-oxadiazole host doped with Coumarin 490 and DCM and is deposited on lithographically patterned Si/SiO2 structures. Bragg reflections caused by the grating diminish the group velocity of photons along some directions of crystallographic symmetry to zero, and the resulting feedback gives rise to laser oscillations. Dispersion relations for photons were calculated analytically and are used to interpret the laser emission spectra.
TL;DR: In this article, a photonic bandgap (PBG) structure is proposed to realize a magnetic surface in the stopband and is used in the waveguide walls to provide magnetic boundary conditions.
Abstract: A novel waveguide using a photonic bandgap (PBG) structure is presented. The PBG structure is a two-dimensional square lattice with each cell consisting of metal pads and four connecting lines, which are etched on a conductor-backed Duroid substrate. This uniplanar compact PBG structure realizes a magnetic surface in the stopband and is used in the waveguide walls to provide magnetic boundary conditions. A relatively uniform field distribution along the cross section has been measured at frequencies from 9.4 to 10.4 GHz. Phase velocities close to the speed of light have also been observed in the stopband, indicating that TEM mode has been established. A recently developed quasi-Yagi antenna has been employed as a broad-band and efficient waveguide transition. Meanwhile, full-wave simulations using the finite-difference time-domain method provide accurate predictions for the characteristics of both the perfect magnetic conductor impedance surface and the waveguide structure. This novel waveguide structure should find a wide range of applications in different areas, including quasi-optical power combining and the electromagnetic compatibility testing.
TL;DR: In this paper, a promising thin-slab light-emitting diode (LED) design was described, which uses a highly efficient coherent external scattering of trapped light by a two-dimensional (2D) photonic crystal.
Abstract: We describe a promising thin-slab light-emitting diode (LED) design, which uses a highly efficient coherent external scattering of trapped light by a two-dimensional (2D) photonic crystal. The light generation region was an unpatterned heterostructure surrounded by the light extraction region, a thin film patterned as a 2D photonic crystal. A six-fold photoluminescence enhancement was observed compared to an unpatterned thin film LED. That corresponded to 70% external quantum efficiency.
TL;DR: In this paper, a photonic bandgap (PBG) reflector was designed using a finite-difference time-domain (FDTD) code, and the FDTD computations provided the theoretical reflector's directivity.
Abstract: This paper introduces two new photonic bandgap (PBG) material applications for antennas, in which a photonic parabolic reflector is studied. It is composed of dielectric parabolic layers associated to obtain a PBG material. The frequency gap is used to reflect and focus the electromagnetic waves. This device has been designed using a finite-difference time-domain (FDTD) code. FDTD computations have provided the theoretical reflector's directivity. These results are in good agreement with measurements, and it appears that the PBG reflector presents the same directivity as a metallic parabola. A second application uses a defect PBG material mode associated with a metallic plate to increase the directivity of a patch antenna. We explain the design of such a device and propose experimental results to validate the theoretical analysis.
TL;DR: The properties of photonic crystal fibers with large air holes can be modeled by a silica rod in air as mentioned in this paper, and it has been shown that the dispersion of such fibers could exceed -2000 ps/mm/km, or they could compensate (to within /spl plusmn/0.2%) the length of standard fiber over a 100nm range.
Abstract: The properties of photonic crystal fibers with large air holes can be modeled by a silica rod in air. Such approximate calculations show that the dispersion of photonic crystal fibers could exceed -2000 ps/mm/km, or they could compensate (to within /spl plusmn/0.2%) the dispersion of 35 times their length of standard fiber over a 100-nm range.
TL;DR: In this article, the optical stop band in the transmission spectra of opals shifts drastically by the infiltration of liquid crystals and the stop band is also found to shift at the phase transition points with changing temperature.
Abstract: Nematic liquid crystals and smectic liquid crystals can be infiltrated into a three-dimensional periodic array of interconnected nanosize voids in opal films prepared by sedimentation of SiO2 spheres of various diameters. The optical stop band in the transmission spectra of opals shifts drastically by the infiltration of liquid crystals. The stop band is also found to shift at the phase transition points with changing temperature. This effect enables the tuning of optical properties of opals as a prototype tunable photonic crystal. This phenomenon can also be used as a measurement method for the refractive index.
Abstract: Electromagnetic band structure can produce either an enhancement or a suppression of spontaneous emission from two-dimensional (2-D) photonic crystal thin films. We believe that such effects might be important for light emitting diodes. Our experiments were based on thin-film InGaAs-InP 2-D photonic crystals at ambient temperature, but the concepts would apply equally to InGaN thin films, for example. We show that the magnitude of Purcell enhancement factor, F/sub p//spl sim/2, for spatially extended band modes, is similar to that for a tiny mode in a three dimensional (3-D) nanocavity. Nonetheless, light extraction enhancement that arises from Zone folding or Bragg scattering of the photonic bands is probably the more important effect, and an external quantum efficiency >50% is possible. Angle resolved photoluminescence from inside the photonic crystal gives a direct spectral readout of the internal 2-D photonic band dispersion. The tradeoffs for employing various photonic crystal structures in high efficiency light-emitting diodes are analyzed.
TL;DR: In this article, the optical stop band of periodic planar arrays of submicron silica spheres and macroporous polymers grown from these silica templates were observed. And the results were compared to the predictions of the scalar wave approximation.
Abstract: We report observations of the optical stop band of periodic planar arrays of submicron silica spheres, and of macroporous polymers grown from these silica templates. The stop-band width and peak attenuation depend on the number of layers and on the dielectric contrast between the spheres and the interstitial regions, both of which are experimentally controlled. The results are compared to the predictions of the scalar wave approximation. This is the first systematic study of the thickness dependence of the stop band in colloidal photonic band gap structures.
TL;DR: In this article, the AlF6/ZnSe multilayer structure developed by means of standard optical technology was found to have a reflection coefficient of more then 99% in the range of incident angles 0°-86° at the wavelength of 632.8nm for s-polarization.
Abstract: AlF6/ZnSe multilayer structure developed by means of standard optical technology. The structure was found to have a reflection coefficient of more then 99% in the range of incident angles 0°-86°at the wavelength of 632.8 nm for s-polarization. The results are likely to stimulate new experiments on photonic crystals and controlled spontaneous emission.
TL;DR: In this paper, the light propagation in 2D photonic crystal waveguides with bends was observed, which were composed of densely-packed holes formed in a GaInAsP thin film.
Abstract: We observed the light propagation in 2-D photonic crystal waveguides with bends, which were composed of densely-packed holes formed in a GaInAsP thin film. Wavelength and polarization dependence of propagation characteristics was observed at λ = 1.47 - 1.60μm.
TL;DR: The concept of a complex effective index for structures of finite length, derived from a generalized dispersion equation that identically satisfies the Kramers-Kronig relations is introduced.
Abstract: We discuss the linear dispersive properties of finite one-dimensional photonic band-gap structures. We introduce the concept of a complex effective index for structures of finite length, derived from a generalized dispersion equation that identically satisfies the Kramers-Kronig relations. We then address the conditions necessary for optimal, phase-matched, resonant second harmonic generation. The combination of enhanced density of modes, field localization, and exact phase matching near the band edge conspire to yield conversion efficiencies orders of magnitude higher than quasi-phase-matched structures of similar lengths. We also discuss an unusual and interesting effect: counterpropagating waves can simultaneously travel with different phase velocities, pointing to the existence of two dispersion relations for structures of finite length.
TL;DR: In this paper, the authors demonstrate the effectiveness of such an approach by fabricating a broadband, low-loss hollow waveguide in the 10-spl mu/m region and measuring its transmission around a 300 bend.
Abstract: The emergence of a dielectric omnidirectional multilayer structure opens new opportunities for low loss broad-band guiding of light in air We demonstrate the effectiveness of such an approach by fabricating a broad-band, low-loss hollow waveguide in the 10-/spl mu/m region and measuring its transmission around a 300 bend The generality of the solution enables the application of the method to many wavelengths of interest important in telecommunication applications as well as for guiding high-power lasers in medical and other fields of use
TL;DR: A combination of advanced silicon-processing techniques was used to create three-dimensional (3D) photonic crystals with a 180-nm minimum feature size that displayed a strong stop band at optical wavelengths.
Abstract: A combination of advanced silicon-processing techniques was used to create three-dimensional (3D) photonic crystals with a 180-nm minimum feature size. The resulting 3D crystal displayed a strong stop band at optical wavelengths from lambda=1.35 microm to lambda=1.95 microm . This is believed to be the smallest 3D crystal with a complete 3D photonic bandgap ever created.
TL;DR: In this article, a light-beam steering that is extremely wavelength dependent has been demonstrated by using photonic crystals fabricated on Si. The scanning span reached 50° with only a 1% shift of incident wavelength at around 1 μm.
Abstract: Light-beam steering that is extremely wavelength dependent has been demonstrated by using photonic crystals fabricated on Si. The scanning span reached 50° with only a 1% shift of incident wavelength at around 1 μm. The resulting angular dispersion is two orders of magnitude larger than that achieved with conventional prisms or gratings. The application of such superprism phenomena promises to enable the fabrication of integrated micro lightwave circuits that will allow more efficient use of wavelength resources when used in wavelength multiplexers/demultiplexers or dispersion compensators by enabling lower loss and broader bandwidth.