共查询到17条相似文献,搜索用时 125 毫秒
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在基于空间光调制器(SLM)的灰度掩模并行制作方法中,基于曝光曲线的线性近似关系,建立了灰度掩模强度透过率的线性近似模型,给出了灰度掩模等级精度的精确控制策略.利用卤化银全息感光材料进行了相关实验,制作了菲涅耳透镜的2阶、8阶和16阶灰度掩模.分析了灰度掩模的边缘模糊效应误差,提出了克服非线性效应对灰度等级精度影响的初步方法. 相似文献
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LiNbO3:Fe:Cu中角度复用的双色全息存储研究 总被引:1,自引:1,他引:0
采用365nm的门光束和633nm的记录光,在LiNbO3:Fe:Cu(Fe:0.15%;Cu:0.01%)晶体中实现了20幅全息光栅的双色复用记录和固定,平均固定效率达到79%,在5.0mm厚的晶体中固定后的动态范围M/#为1.50。实验研究了门光束光强、记录光与门光束的光强比对双色复用存储性能的影响,结果表明,增大门光束光强、减小记录光与门光束的光强比,有利于提高双色记录的复用全息图的平均固定效率以及动态范围;而增大记录光与门光束的光强比,可以提高双色记录灵敏度。 相似文献
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为了使全息平面的条纹能见度达到最佳值,全息记录要求参考光束和物光束光强比精确平衡。由于两束光最佳光强比随实验条件变化很大,所以希望两光束的光强比能改变。通常可变密度的分束器来改变光强比,但分束器上的金属膜有很高的损耗,且局部的加热会诱发两输出光束之间产生一个相移,影响条纹的稳定性。光束调节时会发生偏折是这种分束器的另一缺点。同时,因光密度随入射光位置不 相似文献
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手性偶氮苯衍生物的光致变色和全息存储特性研究 总被引:5,自引:4,他引:5
研究了手性偶氮分子N-[4-(4-十二烷氧基苯基偶氮)苯甲酰]-L-谷氨酸(C12-Azo—L-Glu)掺杂聚合物薄膜的光致变色特性。利用C12-Azo-L-Glu掺杂聚甲基丙烯酸甲酯(PMMA)薄膜的可逆光致异构过程.以线偏振的氩离子激光(488nm)作抽运光和写入光,线偏振氦氖激光(632.8nm)作再现光和读出光.探讨了光致双折射和全息光学存储过程中.衍射信号强度与氩离子激光功率的关系。实验结果表明C12-Azo-L-Glu具有响应时间快、可擦重写、耐疲劳度高的特点,可用作实时存储材料。 相似文献
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A fully adaptive normalized nonlinear complex-valued gradient descent (FANNCGD) learning algorithm for training nonlinear (neural) adaptive finite impulse response (FIR) filters is derived. First, a normalized nonlinear complex-valued gradient descent (NNCGD) algorithm is introduced. For rigour, the remainder of the Taylor series expansion of the instantaneous output error in the derivation of NNCGD is made adaptive at every discrete time instant using a gradient-based approach. This results in the fully adaptive normalized nonlinear complex-valued gradient descent learning algorithm that is suitable for nonlinear complex adaptive filtering with a general holomorphic activation function and is robust to the initial conditions. Convergence analysis of the proposed algorithm is provided both analytically and experimentally. Experimental results on the prediction of colored and nonlinear inputs show the FANNCGD outperforming other algorithms of this kind. 相似文献
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WANGYunshan 《半导体光子学与技术》1996,2(2):118-123
When recording a hologram,we should control the.exposure amount which is in nonlinear area of the characteristic curve of complex amplitude transmittance τ~exposure H,the hologram can diffeact some higher-order diffracted photograph.The amount of diffracted order has something to do with the recording angle between object beam and reference beam,is concerned with the ship of transmission curve.The phase difference.If the phase difference increased a time,the number of diffracted fringes also increased a time,it is similar to a fringe multipler,that it is obvious to in-crease the precision of interferometry.Nonlinear recording of double exposure method is discussed,and the formula of intensity distribution of second order diffracted photogra-phy,and experimental results are given. 相似文献