共查询到20条相似文献,搜索用时 296 毫秒
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为实现一束激光在90°锥形范围内的扫描,利用液晶空间光调制器在光束偏转控制时精度高、无机械惯性等优点,研究并建立了基于液晶空间光调制器的光束偏转和角放大光路系统。提出了空间光调制器的可编程相位调制算法和角放大光路结构,推导了空间光调制器光束偏转角度与相位灰度驱动图的关系,设计了角度放大倍率高于22倍的角放大光路系统。在此基础上,建立了光束扫描控制实验系统,对该装置角度出射范围进行了测量,将实际的角放大倍率与设计值进行对比。实验结果表明:研制系统的出射视场角可达91.22°,并可通过畸变校正实现出射视场角范围内的规则形状扫描。该研究在光束敏捷控制、无线激光通信、目标搜索与追踪等领域具有重要的研究价值和应用前景。 相似文献
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在利用液晶空间光调制器(LCSLM)产生涡旋光束时,入射光的偏振方向对涡旋的产生有着明显的影响。从液晶空间光调制器的工作原理出发,研究了不同偏振方向的线偏振光在通过LCSLM的相位调制后,涡旋光束产生的变化。通过模拟仿真与实验结果的比较,发现随着线偏振光的偏振方向与液晶分子光轴夹角的增大,液晶空间光调制器的调制误差变大,所产生的涡旋光束的质量变差。当夹角大于4.725°时,涡旋光束的质量明显变差。而随着夹角继续增大,LCSLM对入射光的调制作用减弱,无法产生涡旋光束。 相似文献
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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 41\,$\mu$m to produce the paraboloid
wavefront with the peak to valley accuracy better than $\la$/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. 相似文献
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平行排列液晶器件的波前调制特性 总被引:18,自引:17,他引:1
设计了一种新型的平行排列液晶相位调制器(LC PM),可在纯相位的模式下进行相位调制,研究了液晶相位调制器的光学特性,理论上给予了分析.对畸变波前进行了调制,在1 cm2的校正面积上,调制后的准确度PV(peak to valley)值接近λ/15(λ=0.6328 μm),RMS(Root Means Square)可达到λ/100,斯特列尔比SR (Strehl Ratio)达到0.989.改变了传统的扭曲向列液晶器件难于进行纯相位调制和得到高准确度调制的缺点,达到了理想的效果. 相似文献
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A spatial light modulator (SLM) is introduced to an optical manipulation system. The real-time reconfigurable feature of the SLM makes it possible to perform an optical manipulation of microparticles without mechanical movements of optical parts. A liquid crystal SLM incorporated in the system forms a Fresnel zone plate (FZP). The beam spot generated by the FZP is imaged on a sample solution by reduction optics. A microparticle in the sample solution is trapped by the beam and manipulated by changing the addressing position of the FZP onto the SLM from a computer. The nonmechanical optical manipulation of microparticles is demonstrated for the first time. 相似文献
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A channel-switching optical add/drop multiplexer with tunable fiber Bragg grating tuned by equivalent-intensity cantilever beam is proposed and experimentally demonstrated. The no-chirped linearly tuning range is about 6.1 nm, which enables it to add or drop 8 channels with channel spacing 100 GHz. It is used in a 4-channel WDM system to test its capability. The adjacent channel isolation is not less than 24 dB. 4-channel lasers modulated by 1.2 Gb/s Non-Return-to-Zero format (NRZ), \{Return-to-Zero\} format (RZ) and 2.5 GHz analogue signals are dropped by the device after transmission over 100 km and the results are given. 相似文献
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FENG Dejun KAI Guiyun ZHANG Weigang HUANG Yonglin LIU Zhiguo DONG Xiaoyi 《Chinese Journal of Lasers》2002,11(1):57-60
1 Introduction Theopticaladd dropmultiplexer(OADM )isexpectedtoplayanimportantroleinfuturewavelengthdivisionmultiplexed(WDM )ringnetwork .Uptonow ,afewschemesofOADMbasedonwavelengthgratingrouter,opticalswitches,arrayedgratingwaveguideandfiberBragg gratings(… 相似文献
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Salter PS Jesacher A Spring JB Metcalf BJ Thomas-Peter N Simmonds RD Langford NK Walmsley IA Booth MJ 《Optics letters》2012,37(4):470-472
We demonstrate an improved method for fabricating optical waveguides in bulk materials by means of femtosecond laser writing. We use an LC spatial light modulator (SLM) to shape the beam focus by generating adaptive slit illumination in the pupil of the objective lens. A diffraction grating is applied in a strip across the SLM to simulate a slit, with the first diffracted order mapped onto the pupil plane of the objective lens while the zeroth order is blocked. This technique enables real-time control of the beam-shaping parameters during writing, facilitating the fabrication of more complicated structures than is possible using nonadaptive methods. Waveguides are demonstrated in fused silica with a coupling loss to single-mode fibers in the range of 0.2 to 0.5 dB and propagation loss <0.4 dB/cm. 相似文献
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活体23Na NMR及在生物医学中的应用 总被引:1,自引:0,他引:1
胞内Na+浓度和跨膜梯度的维系对于保持组织细胞的正常生理状态具有重要的作用.本文详细介绍了生物组织细胞内Na+测定的23Na NMR方法,并讨论了23Na NMR在生理病理学研究和疾病诊断等生物医学领域内的应用。 相似文献
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Te -kao Wu Charles W. Chandler 《International Journal of Infrared and Millimeter Waves》1993,14(6):1191-1199
Three optical beam forming techniques are identified as applicable to large spaceborne phased array antennas. They are 1) the fiber replacement of conventional RF phased array distribution and control components, 2) spatial beam forming, and 3) optical beam splitting techniques. Two novel optical beam forming approaches, i.e., the spatial beam forming with a smart pixel spatial light modulator (SLM) and the optical beam splitting approaches are conceived with integrated quasi-optical components. Also presented are the transmit and receive array architectures with the new SLM. 相似文献