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1.
Fabrication of High Quality Three-Dimensional Photonic Crystals   总被引:2,自引:0,他引:2       下载免费PDF全文
High quality colloidal photonic crystals made from polystyrene spheres with diameter 24Ohm are fabricated by the vertical deposition method. The scanning electron microscopy (SEM) and the transmittance spectrum are used to characterize the properties of the photonic crystal. The SEM images show that there are few lattice defects. The transmittance of the photonic crystal is above 75% in the pass band at 700nm and is lower than 5% at the centre of the band gap, respectively. It is found that proper concentration is a very important factor to fabricate the photonic crystal when the diameter of the spheres is lower than 30Onm.  相似文献   

2.
冯天华  戴峭峰  吴立军  郭旗  胡巍  兰胜 《中国物理 B》2008,17(12):4533-4540
Application of the pressure controlled isothermal heating vertical deposition method to the fabrication of colloidal photonic crystals is systematically investigated in this paper. The fabricated samples are characterized by scanning electron microscope and transmission spectrum. High-quality samples with large transmissions in the pass bands and the sharp band edges are obtained and the optimum growth condition is determined. For the best sample, the transmission in the pass bands approaches 0.9 while that in the band gap reaches 0.1. More importantly, the maximum differential transmission as high as 0.1/nm is achieved. In addition, it is found that the number of stacking layers does not increase linearly with concentration of PS spheres in a solution, and a gradual saturation occurs when the concentration of PS spheres exceeds 1.5 wt.%. The uniformity of the fabricated samples is examined by transmission measurements on areas with different sizes. Finally, the tolerance of the fabricated samples to baking was studied.  相似文献   

3.
We investigate the propagation properties of hetero-phononic crystal waveguides by the improved eigen-mode matching theory, which can be used at same time to calculate both the transmission (reflection) coefficient and band structure. The numerical results show that the transmission frequency range is the same as the common range for two uniform waveguides composing the hereto-system, and the gap of any composite waveguide is also the gap of the hetero-phononic crystals waveguide.  相似文献   

4.
We propose a ring photonic crystal working in the near infrared region, where the air holes in the background material GaAs are arranged to form a series of rings. We find that the band gaps do not depend on the incident direction, and only a small number of rows are needed to create a frequency gap in the transmission spectrum. The transmission spectra of both P and S polarizations show that there is a complete bandgap in the hexagonal ring photonic crystals and the ratio of gap width to mid-gap frequency is as high as 11%.  相似文献   

5.
蓝鼎  王育人  张荫民  王维  吴忠华 《中国物理 C》2009,33(11):1016-1018
The monodisperse polystyrene spheres are assembled into the colloidal crystal on the glass substrate by vertical deposition method, which is aimed at the so-called photonic crystal applications. The structural information of the bulk colloidal crystal is crucial for understanding the crystal growth mechanism and devel- oping the various applications of colloidal crystal. Small-angle X-ray scattering (SAXS) technique was used to obtain the bulk structure of the colloidal crystal at Beamline lW2A of BSRF. It is found that the SAXS pattern is sensitive to the relative orientation between the colloidal sample and the incident X-ray direction. The crystal lattice was well distinguished and determined by the SAXS data.  相似文献   

6.
A method of designing a photonic crystal grating slow-wave circuit in which the cylinders of the 2D photonic crystals dot on a cross-sectional plane is established by calculating the band structures of the 2D photonic crystals, and the eigenfrequency of the equivalent waveguide grating. For calculating the band structures, the eigenvalue equations of the photonic crystals in the system of photonie crystal grating slow-wave circuit are derived in a special polarization mode. Two examples are taken to show the method. The design result is validated by the scattering parameters of the same circuit. The result indicates that there exists no photonic band gap if the metal gratings do not extend into the photonic crystals; the design of the circuit without the metal gratings extending into the photonie crystals is less flexible than that with the metal gratings extending into the photonic crystals.  相似文献   

7.
Fabrication of fiber-embedded multi-core photonic crystal fibers   总被引:2,自引:0,他引:2  
A novel fabrication method of multi-core photonic crystal fibers is proposed on the basis of a fiber-embedded technique. A taper tower is used to modify the structures of the fiber preform, and four steps of fiber fabrication and different structures of fiber samples are given. The mode structures and beating characteristics of a photonic crystal fiber sample with two successive cores are investigated in detail with the help of a supercontinuum light source, a charge-coupled device (CCD) camera, and an optical spectrum analyzer. The test results show a clear beating phenomenon between two orthotropic polarization modes with a 2.8-nm peak interval in wavelength.  相似文献   

8.
Triple-periodical photonic crystal heterostructures (ABC)^N for multichannel ultranarrow transmission filters are designed and demonstrated. Theoretical calculations and experimental results from TiO2/SiO2 constructed heterostructures show that each transmission channel can reach subnanometre scale, implying technical importance of such structures in the fields of integrated optics, optical communications for the design of high-performance multichannel filters, wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM) systems, etc.  相似文献   

9.
We take a finite dielectric photonic crystal as a homogeneous slab and have extracted the effective parameters. Our systematic study shows that the effective permittivity or permeability of dielectric photonic crystal is negative within a band gap region. This means that the band gap might act as ε-negative materials (ENMs) with ε 〈 0 and μ 〉 0, or μ-negative materials (MNMs) with ε 〉 0 and μ 〈 0. Moreover the effective parameters sensitively rely on size, surface termination, symmetry, etc. The effective parameters can be used to design full transmission tunnelling modes and amplify evanescent wave. Several cases are studied and the results show that dielectric photonic band gap can indeed mimic a single negative material (ENM or MNM) under some restrictions.  相似文献   

10.
Degeneracy and Split of Defect States in Photonic Crystals   总被引:4,自引:0,他引:4       下载免费PDF全文
黄晓琴  崔一平 《中国物理快报》2003,20(10):1721-1724
One-dimensional photonic crystals with two or more structural defects are studied. We observed an interesting characteristic of transmission band structure of photonic crystals with defects using the transmission-matrix-method simulation. The transmission states in the wide photonlc band gap caused by defects reveal degeneracy and split in certain conditions. Every split state is contributed by coupling of all defects in a photonic crystal.Using the tight-binding method, we obtain an approximate analytic expression for the split frequency of photonic crystals with two structural defects.  相似文献   

11.
The theoretical and experimental investigations of photonic band gaps in one-dimensional photonic crystals created by micromatchining silicon, which have been performed by the author as part of his doctoral dissertation, are presented. The most important result of the work is the development of a method of modeling photonic crystals based on photonic band gap maps plotted in structure–property coordinates, which can be used with any optical materials and in any region of electromagnetic radiation, and also for nonperiodic structures. This method made it possible to realize the targeted control of the optical contrast of photonic crystals and to predict the optical properties of optical heterostructures and three-component and composite photonic crystals. The theoretical findings were experimentally implemented using methods of micromatchining silicon, which can be incorporated into modern technological lines for the production of microchips. In the IR spectra of a designed and a fabricated optical heterostructure (a composite photonic crystal), extended bands with high reflectivities were obtained. In a Si-based three-component photonic crystal, broad transmission bands and photonic band gaps in the middle IR region have been predicted and experimentally demonstrated for the first time. Si–liquid crystal periodic structures with electric-field tunable photonic band-gap edges have been investigated. The one-dimensional photonic crystals developed based on micromatchining silicon can serve as a basis for creating components of optical processors, as well as highly sensitive chemical and biological sensors in a wide region of the IR spectrum (from 1 to 20 μm) for lab-on-a-chip applications.  相似文献   

12.
13.
This paper describes the fabrication of opal-based photonic crystal heterostructures. These heterostructures were created by using multilayer deposition of silica and polystyrene spheres. The fabricated structures involved both different lattice constants and different dielectric constants. Single and double heterostructures working in the visible region were fabricated by using techniques described here. The optical properties of these heterostructures were investigated experimentally and showed the superposition of the properties of each individual crystal region as well as optical signatures due to inter-layer defects.  相似文献   

14.
Chen JY  Chen YC  Wei CM  Chen YF 《Optics letters》2011,36(13):2563-2565
FeCo/NiO half-shell arrays were fabricated based on the periodic monolayer polystyrene spheres. The two-dimensional magnetic periodic arrays form well-defined photonic crystals with pronounced stop bands. Quite interestingly, it is found that the stop bands can be tuned by an external magnetic field. The underlying mechanism is attributed to the controllable dielectric constant of the magnetic FeCo film under an applied magnetic field. The results shown here may open up an avenue for magnetically tunable photonic crystal stop bands, which may be useful for the creation of new magneto-optical devices.  相似文献   

15.
G.Q. Liu  H.H. Hu  Z.S. Wang  Z.M. Liu 《Optik》2011,122(1):9-14953
High quality photonic crystal heterostructures with a thin titania planar defect layer between its two constitutional photonic crystals were fabricated and their structural and optical properties were analyzed. The results suggest that the thin planar defect layer is beneficial to separate the two constitutional photonic crystals from each other and to reduce the roughness of the interface. The quality of the resulting photonic crystal heterostructures is improved largely and the main features of the photonic band gaps of the two constitutional photonic crystals are inherited. The predominant optical quality of these heterostructures (e.g. deep double photonic band gaps and steep photonic band edges) may afford new flexibility and functionality for engineered photonic behavior in practical devices such as late-model light-operated switches.  相似文献   

16.
Any photonic crystal is in practice periodic with some inevitable fabricational imperfections. We have measured angle-resolved transmission of photons that are multiply scattered by this disorder in strongly photonic crystals. Peculiar non-Lambertian distributions occur as a function of frequency: due to internal diffraction, wide angular ranges of strongly reduced diffuse transmission coincide with photonic stop bands, while enhancements occur for directions outside stop gaps. We quantitatively explain the experiment with a model incorporating diffusion and band structure on equal footing. We predict that in the event of a photonic band gap, diffuse light at frequencies near band gap edges can exit only along isolated directions. Angle-resolved diffuse transmission appears to be the photonic equivalent of angle-resolved photoelectron spectroscopy.  相似文献   

17.
In this paper the omni-directional reflection bands in one-dimensional plasma photonic crystal (PPC) have been studied theoretically. We present the study of plasma photonic crystal, having alternate regions of plasma?dielectric (Al2O3 or ZnS). Reflectances from this periodic multilayered structure in TE- and TM-modes are calculated for different angles of incidence in microwave region for omni-directional reflection bands. The reflectance is obtained by solving a Maxwell's equation using a translational matrix method. In addition to this, we have also studied the effect of variation of plasma width as well as plasma density on the reflection properties of plasma dielectric photonic crystal in TE- and TM-modes. The study of reflectance bands of such plasma photonic crystals shows that it can be used as omni-directional reflector.  相似文献   

18.
Three-dimensional (3D) photonic crystal exhibit direction-selective transmission with respect to the center frequency of the stop gap. As a model system, the stop gap of a 3D fcc inverted-opal photonic crystal is studied in the microwave regime in detail using 3D polyamide models. The difference in the direction-selective transmittance between crystals grown in two different high symmetry directions is experimentally shown and compared to numerical simulations.  相似文献   

19.
A non-close-packed three-dimensional photonic crystal of titania hollow spheres has been fabricated. The fabricated process is based on the silica template technique, thermal sintering, and the sol–gel process. The band-structure calculations and optical measurements both indicate that a quasi-full three-dimensional photonic bandgap located at the visible wavelength has been presented between the eighth and ninth bands. This indicates that the non-close-packed structure of titania hollow spheres was easier to open the complete photonic bandgaps than other face-centered cubic structures made by self-assembling methods at the visible region.  相似文献   

20.
A metallodielectric photonic crystal with photonic band gaps in near infrared regime has been constructed using layer-by-layer stacking of two-dimensional micro-size metal-coated dielectric spheres array. In transmission spectra two photonic band gaps are observed at 1.38 μm and 2.46 μm, which are in agreement with theoretical calculations. Experimental results show that the photonic band gaps can be realized with about ten layers. The structure with metallic microspheres provides us a novel way for fabrication of near infrared metallic photonic crystals.  相似文献   

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