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1.
A holographic technique for fabricating 3D photonic crystal is presented. The key element in the fabrication system is a holographic optical element (HOE) consisting of three gratings. Used in combination with a mask, the HOE can generate four beams under single illuminating beam, and 3D lattice structures can be formed by the interference of the four beams. Holographic approach is used to make HOE, so large area lattice structures can be fabricated. Numerical simulations indicate that beam intensity ratio of central beam to outer beam is one of the factors that affects the structures fabricated in photoresist, and high diffraction efficiency of the gratings in HOE is favorable when using cw laser with relatively low power as light source. Experimental results show clear 3D lattice structures fabricated using the HOE, verifying the effectiveness of the technique. 相似文献
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<正>The natural sedimentation method combining with the isothermal heating evaporation induced selfassembly is presented to fabricate three-dimensional(3D) colloidal crystals in the curved cavity of the fiber end face.A~50-μm-deep cavity is etched by hydrofluoric acid.The colloidal crystals are characterized by optical and scanning electron microscopy.A 1380-nm stop band is observed by measuring their transmission spectra at normal incidence by an optical spectrum analyzer(OSA). 相似文献
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Yanping Liu 《Applied Surface Science》2007,253(21):8571-8574
Three-dimensional (3D) composite colloidal photonic crystals with SiO2 core and ZnO shell were fabricated on borosilicate glass (BSG) substrate by a two-stage deposition method. Scanning electron microscopy (SEM) measurements show that both the pre-deposited SiO2 and SiO2/ZnO core-shell structures are oriented with their (1 1 1) axes parallel to the substrates. Optical measurement reveals that the periodic arrays exhibit a photonic band gap in the (1 1 1) direction. The optical properties of SiO2/ZnO core-shell structures strongly depend on the size dispersions of colloidal spheres and the intrinsic defects in the sample. 相似文献
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R. Katouf T. Komikado M. Itoh T. Yatagai S. Umegaki 《Photonics and Nanostructures》2005,3(2-3):116-VI
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. 相似文献
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Yu. V. Gulyaev S. A. Nikitov D. A. Usanov A. V. Skripal V. N. Posadskii V. S. Tiazhlov A. V. Baykin 《Doklady Physics》2014,59(10):437-440
Structures containing periodically alternating elements, which are a source of high-order waves, are investigated as low-dimensional waveguide microwave photonic crystals. The band character of the transmittance and the reflectance of a photonic crystal, which consists of sequentially alternating dielectric layers and thin metallic plates partially overlapping the waveguide section, is revealed by the numerical modeling and the experimental investigation of amplitude-frequency characteristics. It has been shown that the application of metallic plates with gaps in the structure of the photonic crystal made it possible to decrease its longitudinal size substantially compared with photonic crystals fabricated based on elements made of alternating dielectric layers with various permittivities. 相似文献
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Using a symmetry-based approach, we have designed polarization-independent waveguides in a 3D photonic crystal. A comprehensive series of numerical experiments, involving the propagation of pulsed signals through long straight waveguide sections and sharp bends, quantitatively evaluates the bend-transmission coefficient over the entire bandwidth of the corresponding guided modes. High (approximately 95%) polarization-independent bend transmission is achieved within a certain frequency range. 相似文献
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P. Viktorovitch B. Ben Bakir S. Boutami J. Louis Leclercq X. Letartre P. Rojo‐Romeo C. Seassal M. Zussy L. Di Cioccio J.Marc Fedeli 《Laser \u0026amp; Photonics Reviews》2010,4(3):401-413
It is emphasized that two‐dimensional photonic crystals (2D PC) have not only a great potential for the development of 2D nanophotonics in the inplane waveguided configuration, but that they may also open the way to other brilliant developments, with an extension to out‐of‐plane operation, along a 2.5D nanophotonics approach. In this 2.5D approach, a 1D–2D high index contrast lateral structuration is combined with a 1D high index contrast vertical structuration, using multilayer membrane stacks including 1D–2D photonic crystal membranes, thus resulting in so‐called 2.5D PC. As a specific illustration of recent achievements along this approach, new families of VCSEL structures are presented. 相似文献
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Prather DW Shi S Pustai DM Chen C Venkataraman S Sharkawy A Schneider GJ Murakowski J 《Optics letters》2004,29(1):50-52
We present and experimentally validate self-collimation in planar photonic crystals as a new means of achieving structureless confinement of light in optical devices. We demonstrate the ability to arbitrarily route light by exploiting the dispersive characteristics of the photonic crystal. Propagation loss as low as 2.17 dB/mm is observed, and proposed applications of these devices are presented. 相似文献
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Tanaka Tomoko Noda Susumu Chutinan Alongkarn Asano Takashi Yamamoto Noritsugu 《Optical and Quantum Electronics》2002,34(1-3):37-43
We have investigated ultra-short pulse propagation through 3D GaAs photonic crystals with a complete photonic band gap in the optical wavelength region. The pulse propagation was calculated by using the finite-differential time-domain (FDTD) method. This is the first time pulse shape measurements have been made using femtosecond pulses. From the experimental results, the shapes of the ultra-short pulses were found to change when the frequency was above the photonic band-gap after the propagation through the photonic crystal, corresponding to the simulation results. 相似文献
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S. G. Romanov 《Physics of the Solid State》2010,52(4):844-854
This paper reports on the measurements (in linearly polarized light) of the transmission and reflection spectra of colloidal
photonic crystals with three-dimensional and one-two-dimensional photonic band structure, i.e., opal films and Langmuir-Blodgett
crystals with a refractive index contrast of ∼1.5: 1.0. It has been shown that the polarization anisotropy is enhanced considerably
in the diffraction resonance range both in transmitted and reflected light, and that the anisotropy in the resonance range
can be as high as 99%. The interaction of photonic crystal eigenmodes has been found to affect the polarization anisotropy.
The assumption has been made that the coincidence of the maxima in polarization anisotropy of the resonant and nonresonant
light reflection in colloidal crystals originates from the disorder in their lattices. The generality of the results obtained
is confirmed by the fact that the polarization anisotropy manifests itself in the same way in colloidal crystals with different
lattice symmetries. 相似文献
13.
The construction of 3D photonic crystals with gaps in the visible or the near-infrared frequency range requires engineering of complex microstructures which are very difficult to realize by etching and micro-fabrication. Consequently, self-ordered systems such as synthetic opals are very promising. Synthetic bare opals are constituted by SiO2 spheres that organize themselves by a sedimentation process in a face centered cubic (fcc) arrangement. Using the plane wave method, we examine the photonic band structures of close-packed opal-based photonic crystals with an SiO2 (n = 1.5) matrix. The incomplete photonic band gaps at the X- and L-points have been studied which correspond to normally incident plane waves onto the (100) and (111) crystal planes. With the transfer matrix method, we model the transmission properties. We find that the incomplete gap at the L-point fully inhibits the transmission of waves propagating in the [111] direction for opal sample thicknesses that are easily obtainable. This property shows that bare opals could be good candidates for complete inhibition of transmission in the near-infrared and visible frequency range for given orientations. 相似文献
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Mazurenko DA Kerst R Dijkhuis JI Akimov AV Golubev VG Kurdyukov DA Pevtsov AB Sel'kin AV 《Physical review letters》2003,91(21):213903
We present the first experimental investigation of ultrafast optical switching in a three-dimensional photonic crystal made of a Si-opal composite. Ultrafast (30 fs) changes in reflectivity around the photonic stop band up to 1% were measured for moderate pump power (70 microJ/cm(2)). Short-lived photoexcited carriers in silicon induce changes in the dielectric constant of Si and diminish the constructive interference inside the photonic crystal. The results are analyzed within a model based on a two-band mixing formalism. 相似文献
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Benjamin Gesemann Stefan L. Schweizer Ralf B. Wehrspohn 《Photonics and Nanostructures》2010,8(2):107-111
We present measurements of the thermal emission properties of 2D and 3D silicon photonic crystals with and without substrate heated resistively as well as passively with an aluminium hotplate. The out-of-plane and in-plane emission properties were recorded and compared to numerical simulation. It turned out that for the in-plane 2D photonic crystal and out-of-plane 3D photonic crystal emission a photonic stop gap effect is visible. For the out-of-plane 2D photonic crystal emission, no photonic bandgap effect is observable but instead strong silicon oxide emission from native oxide inside the pores of silicon are observable. A model for the modified thermal emission is presented. 相似文献
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T.S. Luk T. Mclellan G. Subramania J.C. Verley I. El-Kady 《Photonics and Nanostructures》2008,6(1):81-VII
An accurate methodology is presented to measure photonic crystal emissivity using a direct method. This method addresses the issue of how to separate the emissions from the photonic crystal and the substrate. The method requires measuring two quantities: the total emissivity of the photonic crystal–substrate system, and the emissivity of the substrate alone. Our measurements have an uncertainty of 4% and represent the most accurate measure of a photonic crystal's emissivity. The measured results are compared to, and agree very well with, the independent emitter model. 相似文献
17.
A photonic quantum-well is constructed by sandwiching a uniform medium between two photonic barriers due to the photonic band gap mismatch, similar to electronic quantum well. The transmission coefficient is calculated by a plane-wave expansion method in combination with multiple-scattering techniques. The transmission peaks indicate that some photonic states exist in a quantized way, satisfying a quantized frequency relation. We also show that the finite photonic potential barrier plays different confined roles on the different photonic levels. The positions and number of the resonant peaks can be artificially tuned by varying the well width. By appropriately choosing the parameters of the well and barrier, a high-quality multichannel filtering can be achieved. 相似文献
18.
We describe the mathematical model and program BAL 3D that enables one to solve numerically three-dimensional Maxwell equations in inhomogeneous media. We present the results of calculations of the electromagnetic-radiation propagation in a 3D quasiperiodic medium (photonic crystal). We found the positions of stop bands in photonic crystals and calculate the reflection coefficients for composite materials consisting of artificial opals with pores filled with water. We compare our results with the experimental data. 相似文献
19.
We demonstrate the negative refraction of microwaves in a metallic photonic crystal prism. The spectral response of the photonic crystal prism, which manifests both positive and negative refraction, is in complete agreement with band-structure calculations and numerical simulations. The validity of Snell's law with a negative refractive index is confirmed experimentally and theoretically. The negative refraction observed corresponds to left-handed electromagnetism that arises due to the dispersion characteristics of waves in a periodic medium. This mechanism for negative refraction is different from that in metamaterials. 相似文献
20.
We demonstrate extremely low transmittance characteristics of photonic crystals (PhCs) with a finite thickness in specific photonic bandgaps (PBGs) through numerical simulation, and clarify its origin. Some of the PhCs support decaying Bloch eigenmodes, whose propagation constant (real part of the Bloch wavenumber) as well as their decay constant (imaginary part) changes with frequency inside the bandgap. Such a class of modes can interfere destructively at the exit end of the crystal depending on their round-trip phase change, which creates comb-like valleys in their transmission spectra. 相似文献