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Nonuniform sampled angular spectrum method by using trigonometric interpolation

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Chinese Physics B 2018年第9期27卷 282-286页

作者： Qiu-Hu Cheng Shi-Yu Wang Meng-Yao Wu Zhen Guo De-Fang Cai Bing-Bin Li School of Physics mid Optoclectronic Engineering.Xidian University XIan 710071.China

The angular spectrum method（ASM） is a popular numerical approach for scalar diffraction calculations. However,traditional ASM has an inherent problem in that nonuniform sampling is precluded. In an attempt to address this limitation,an improved trigonometric interpolation ASM（TIASM） is proposed, in which the fast Fourier transform（FFT） is replaced by a trigonometric interpolation. The results show that TIASM is more suitable to situations in which the source field has a simple and strong frequency contrast, irrespective of whether the original phase distribution is a plane wave or a Fresnel zone plate phase distribution.

关键词： wave optics diffraction Fourier optics diffraction efficiency

Effect of polarization on efficiency of volume Bragg grating filter

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Chinese Optics Letters 2010年第8期8卷 738-740页

作者：郑浩斌何焰蓝谭吉春丁道一刘一星于晓燕郑光威王逍王晓东 Science College National University of Defense Technology Opto-Electric Science and Engineering College National University of Defense Technology Research Center of Laser Fusions China Academy of Engineering Physics

diffraction efficiency of volume Bragg grating, whose period is in the same order as the incident wavelength, is related to the polarization direction of the incident linear polarized beam. When two linearly polarized recording beams with the same polarization direction are used for recording volume Bragg gratings in a photopolymer with diffusion amplification, the azimuth of polarization of the reconstruction beam influences the diffraction efficiency of the grating. When the probe beam is linearly polarized and oriented orthogonally to the grating vectors, the ±1-order diffraction beams are also linearly polarized with polarization direction parallel to that of the probe beam. According to the results, a two-dimensional nonspatial optical filter consisting of the volume Bragg gratings would achieve significantly higher efficiency.

关键词： Amplification Bragg gratings diffraction efficiency Probes

Improvement of photorefractive properties in Hf:Fe:LiNbO_3 crystals with various [Li]/[Nb] ratios

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Chinese Physics B 2010年第9期19卷 416-419页

作者：孙秀冬石宏新骆素华孟庆鑫姜永远 Department of Physics Harbin Institute of Technology

Photorefractive properties of Hf：Fe：LiNbO3 crystals with various [Li]/[Nb] ratios have been investigated at 488 nm wavelength based on the two-wave coupling experiment. High diffraction efficiency and large recording sensitivity are observed and explained. The decrease in Li vacancies is suggested to be the main contributor to the increase in the photoconductivity and subsequently to the induction of the improvement of recording sensitivity. The saturation diffraction efficiency is measured up to 80.2%, and simultaneously the recording sensitivity of 0.91 cm/J is achieved to in the Hf：Fe：LiNbO3 crystal grown from the melt with the [Li]/[Nb] ratio of 1.20, which is significantly enhanced as compared with those of the Hf：Fe：LiNbO3 crystal with the [Li]/[Nb] ratio of 0.94 in melt under the same experimental conditions. Experimental results definitely show that increasing the [Li]/[Nb] ratio in crystal is an effective method＇for Hf：Fe：LiNbO3 crystal to improve its photorefractive properties.

关键词： diffraction efficiency recording sensitivity Hf:Fe:LiNbO3 crystals

Effects　of　Change　in　the　Average　Permittivity　on　the　Volume　Hologram

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Chinese Journal of Lasers 1995年第6期B4卷 537-542页

作者： CHEN Xiyuan(Physics Section,Section,Fushun Petroleum Institute, Fushun 113001, China)(Received 21 Nov. 1994 Review manuscript received & Mar. 1995) Fushun Petroleum Inst Fushun China

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关键词： volume hologram coupled wave equation diffraction efficiency

Diffractive characteristics of the liquid crystal spatial light modulator

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Chinese Physics B 2007年第6期16卷 1665-1671页

作者：曹召良穆全全胡立发刘永刚宣丽 State Key Laboratory of Applied Optics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

The liquid crystal spatial light modulator （LC SLM） is very suitable for wavefront correction and optical testing and can produce a wavefront with large phase change and high accuracy. The LC SLM is composed of thousands of pixels and the pixel size and shape have effects on the diffractive characteristics of the LC SLM. This paper investigates the pixel effect on the phase of the wavefront with the scalar diffractive theory. The results show that the maximum optical path difference modulation is 41μm to produce the paraboloid wavefront with the peak to valley accuracy better than λ/10. Effects of the mismatch between the pixel and the period, and black matrix on the diffraction efficiency of the LC SLM are also analysed with the Fresnel phase lens model. The ability of the LC SLM is discussed for optical testing and wavefront correction based on the calculated results. It shows that the LC SLM can be used as a wavefront corrector and a compensator.

关键词： liquid crystal spatial light modulator diffraction efficiency pixel wavefront

提高重铬酸盐明胶全息图衍射效率的一种新方法

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北京师范学院自然科学学报 1987年第4期 27-29页

作者：张存林张光勇北京师范学院物理系

本文根据重铬酸盐明胶的性质,提出了一种处理重铬酸盐明胶板的新方法——两步法,得到了较好的实验结果。

关键词： Dichromated gelatin diffraction efficiency Processing Hologram.

A new photopolymerizable holographic recording material based on acrylamide and N-hydroxymethyl acrylamide

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Chinese Physics B 2005年第10期14卷 2004-2008页

作者：弓巧侠王素莲黄明举干福熹 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China School of Physics and Information Optoelectronics Henan University Kaifeng 475000 China

A new polyvinylalcohol-based photopolymeric holographic recording material has been developed. The recording is obtained by the copolymerization of acrylamide and N-hydroxymethyl acrylamide. diffraction efficiencies near 50% are obtained with energetic exposure of 80mJ/cm^2. N-hydroxymethyl acrylamide can improve the optical quality of the film. With the increase of the concentration of N-hydroxymethyl acrylamide, the flatness of the film increases, scattering reduces and the straight image is clearer with a small distortion. The postexposure effect on the grating is also studied. The diffraction efficiency of grating increases further during postexposure, gradient of monomer exists after exposure.

关键词： photopolymer holographic storage sensitivity diffraction efficiency

Highly concentrated phenanthrenequinone-doped poly(MMA-co-ACMO) for volume holography

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Chinese Optics Letters 2018年第11期16卷 31-35页

作者： Fenglan Fan Ying Liu Yifan Hong Jinliang Zang Guoguo Kang Tianbo Zhao Xiaodi Tan School of Optoelectronics Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Cluster Science of Ministry of Education School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Fujian Provincial Key Laboratory of Photonics Technology College of Photonic and Electronic EngineeringFujian Normal UniversityFuzhou 350007China Corresponding author： xtan@*** corresponding author：bit_bipt@***

Novel composite materials are synthesized by incorporating N-acryloylmorpholine(ACMO) in highly concentrated phenanthrenequinone(PQ) doped poly(methyl methacrylate)(PMMA). The photosensitizer concentration of PQ was increased from 0.7 wt. % to 1.8 wt. %. The doping of ACMO component results in a higher diffraction efficiency and photosensitivity than a typical PQ/PMMA system. The enhanced performance of the material may stem from the ACMO molecules, which might open a new route for improving the holographic performance of the PQ/PMMA photopolymer.

关键词： Composite materials diffraction efficiency Molecules Polymethyl methacrylate Volume holography

Five-port beam splitter of a single-groove grating

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Chinese Optics Letters 2018年第7期16卷 6-9页

作者：项长铖周常河贾伟吴俊 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China Institute of Photonics Technology Jinan University Guangzhou 510632 China

A single-groove grating for five-port TE-polarization beam splitting under normal incidence at the wavelength of 1550 nm is presented. The transmitted diffraction efficiency of the gratings is over 94.5% with uniformity better than 2%. A physical view of diffraction inside the grating is presented by the simplified modal method（SMM）.Initial parameters of the grating profiles are obtained by use of SMM and then optimized by employing rigorous coupled-wave analysis and the simulated annealing algorithm.

关键词： Beam splitters diffraction efficiency diffraction gratings Effective refractive index Optical components Rigorous coupled wave analysis