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Using two dimensional FD method, we analyze the effects of photonic crystal parameters on threshold current in photonic crystal vertical cavity surface emitting laser. Results show that threshold current increases with PC holes diameter and decreases with pitch.
Mutiwavelength lasers are of great interest as their wide applications. In this paper, a novel multiwavelength pulse Brillouin Erbium-doped fiber laser was demonstrated and its principle was given. An electro-optic modulator (EOM) was used to modulate continue wave into pulse light. The results show that, the peak values are unstable, about ±3dB, but the wavelength interval was stable, about 0.088nm...
We demonstrate an improved technique to grow glancing angle nanostructured thin films of silver and copper using electron-beam evaporation. Silver has particular interest for optical metamaterial activity, but unlike most other metals, the surface mobility of these atoms makes it difficult to grow distinct nanocolumns. By cryogenically cooling the substrate, we demonstrate that these metals can show...
A composed of Si nanowire and conducting polymer (Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate), PEDOT:PSS) with core/shell array structure as inorganic-organic hybrid photoanode is proposed and characterized. For the hybrid photoanode design, a PEDOT/PSS layer conformally coated on Si nanowire arrays by solution filling and drying method, which is employed to collect photogenerated holes...
In this paper some key technologies of an optical cavity for a compact Terahertz(THz) Source Based on Free Electron Lasers(FEL) were studied. Firstly, the theory of THz radiation was analyzed by some calculations. The high quality electronic bunch beams with energy 5.6-9.9MeV can produce THz radiation with frequency 1-10THz. Secondly, the configuration of the optical cavity was calculated and studied,...
Light emitting diodes (LEDs) is an important solid-state light source, which has the advantage of long lifetime and low cost. As a semiconductor photoelectric device, the electron-beam irradiation on LEDs brings the deep level defect acting as the compensation of the chemical doping in LEDs. In this paper the influence of low-energy and low-dose electron-beam irradiation on the GaN-based LEDs has...
When the star sensor with high dynamic rotation, blurred image preprocessing technique of the star sensor is need to discuss in detailed. Firstly, the motion-blurred image model in star sensor is given. Then, applying sub-windows technique to improve the dynamics of the star sensor and dynamic compensation for the area starlight reached, which adopt the inverse process of the generation mechanism...
Thirty nanosecond 1.064 μm laser pulses separated by 150 nanoseconds have been shown up to ten times material removal rates while minimizing redeposition and heat-affected zones. The diameter of hole entrance is approximately 450 μm and half hole taper angle is 12 degree. The internal wall of the hole is bright black, no recast layer, no microcrack, smooth and no burr. The laser bursts drilling model...
The optical properties of porous SiGe/Si multilayer films prepared through electrochemical anodization have been investigated. The visible luminescence spectra with multiple emission peaks have been detected in the temperature range from 10 K to room temperature. Photoluminescence (PL) with narrow band width is observed due to the wavelength selective effect of the microcavity. The resonance of the...
A new photochromic diarylethene compound, 1-(2-methylpyridine)-2-[2-methyl-5-(3-methoxylphenyl)-3-thienyl]perfluorocyclopentene(1a) was synthesized. its photochromic and fluorescent properties have been investigated in detail. While, fluorescence properties in different solution have also been discussed. The results of the research demonstrated that it has shown good photochromic behavior and relatively...
For the features of the optical transmission in photonic crystal fiber the minimum roots of mean square search method was proposed. The minimum root-mean -square search method was used to estimate the deviation between the theory of the Localized Basis Functions Method and experimental result of optical transmission in photonic crystal fiber. The experimental result was the light intensity distribution...
CO2 laser (wavelength 10.6 μm) has important applications in laser surgery, material processing, infrared sensors and imaging. CO2 laser optical waveguides are gaining a central position in these applications. Glass-drawing technique and sol-gel methods have been used to prepare GeO2 and germania-based glass hollow waveguides. In this work, a GeO2 glass hollow waveguide sample was fabricated by using...
Abstract-the 3D integration and packaging of semiconductor devices has gone through a paradigm shift over the last decade. The 3D technology outperforms conventional semiconductor assembling methods in density, cost, and performance simultaneously. This paper summarizes characteristics,platforms, approaches, and trends in 3D semiconductor optoelectronics.
In this paper, we extend a new registration framework from scalar image to diffusion tensor image. As the extension from scalar to tensor image is non-trivial, we write the process in detail. The registration framework is based on polynomial expansion transform. The idea of polynomial expansion is that the image is locally approximated by polynomials at each pixel. Registration algorithms are developed...
Edge enhancement is a key part of image processing in order to sharpen the edge and optimize the visual quality of the input image. This paper proposes novel edge-directed enhancement spatial phase filters based on the generalized radial Hilbert transform theory. The simulated results showed that the proposed spatial phase filters are more efficient and flexible for edge-directed enhancement than...
From the point of signal processing in frequency domain, a scheme for the return-to-zero (RZ) to nonreturn-to-zero (NRZ) data format converter based on a tunable microwave photonic filter is experimentally demonstrated. A two-tap, intensity modulated and dispersion involved system is introduced to realize the conversion function. The experimental results shows good performance, tunability and reconfigurability.
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