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1.
本文介绍了无明胶重铬酸盐全息记录软片(简称NGD)的感光成像机理。实验研究了NGD全息图的后处理过程对衍射效率和表面灰雾的影响,给出了处理时间与衍射效率,表面灰雾的关系曲线,提出了一种适用于这种新材料后处理的方法。  相似文献   

2.
以环氧树脂为成膜树脂,甲基丙烯酸甲酯为光聚合活性单体,研制了一种双固化型全息用光致聚合物材料。通过成膜树脂配方的选取和光敏染料的选取优化了样片的配方组成,用457nm的蓝光在样片中记录全息光栅,用632.8nm的红光作为探针光,研究了样片的衍射效率、灵敏度、折射率调制度、预曝光量和收缩率等全息性能,测试结果表明单体的含量与组分的选取是影响样片衍射效率的主要因素,同时样片的制膜工艺对其全息性能也有很大的影响,通过配方的调整和制膜工艺的优化,部分样片的综合性能已基本达到实用化的需要。  相似文献   

3.
采用溶液聚合法合成了水溶性的甲基丙烯酸丁酯-甲基丙烯酸(BMA-MA)共聚物,以这种共聚物为成膜树脂制备了光致聚合物全息材料,研究了光致聚合物全息材料的光敏性、衍射效率、空间频率响应、折射率调制度、曝光能量常数等全息性能。结果表明,在记录信号空间频率为1580 cy/mm时,以BMA-MA共聚物为成膜树脂的光致聚合物全息材料的灵敏度可达15 mJ/cm2,最大衍射效率为92.8%,曝光能量常量为10.9 mJ/cm2,衍射效率随所记录信号空间频率的增加而降低,材料的最大折射率调制度为2.85×10-3,是一种具有一定应用前景的光致聚合物全息材料。  相似文献   

4.
本文提出了一种点阵全息图衍射效率的测试方法,其优点在于巧妙地让零级与正负二级不能进入聚光系统,只有正负一级可以被记录,避开被测点干涉条纹方向变化影响的可能,并介绍依照这个方法研制出的一种点阵全息衍射效率的测量设备,该设备可以用于检测多种点阵全息防伪标识产品质量优劣,给企业用户提供可依据的识别工具。  相似文献   

5.
提出一种复合同轴全息透镜的设计制作方法。该设计方法采用两片离轴全息透镜复合,按使用情况在布喇格条件下进行消像差设计。制作的全息透镜具有衍射效率高和像差小的特点,适合任意给定再现波长的窄带光场合。实验研制了一个全息透镜,其再现衍射效率达到63% 。  相似文献   

6.
改进的防伪全息标识衍射效率测量系统   总被引:1,自引:0,他引:1  
何瑾  刘铁根  孟卓  杨莉珺 《光电工程》2007,34(9):89-92,96
提出一种激光全息特性参数检测方法.以不稳定度为5%的He-Ne激光器为光源,利用同一光束分成的反射光和透射光光强度比例恒定的性质,实时探测衍射光强与反射光强,得到全息防伪标识的衍射效率.给出了实际入射光强与根据反射光强计算得来的入射光强两者的对比曲线,以及对8版不同样品衍射效率的测量结果.实验数据表明:透射光强测量值相对误差不超过0.29%;衍射效率测量值相对误差最大值不超过0.81%,比原方法测量精度提高近一倍.  相似文献   

7.
林峰 《国际防伪》2007,(4):56-57
全息产品的应用越来越广,特别是纸基激光全息图的出现,使得研究背景色对激光全息图案效果的影响显得尤为迫切。我们经过一系列的实验,初步分析了背景色对激光全息图案效果的影响。衍射效率作为评测激光全息图效果的一个重要参数,我们着重研究了它和背景色之间的关系。本文就它们之间的关系以及其形成原因做了一些初步的分析,希望能给大家一些帮助。  相似文献   

8.
本文提出了测量点阵全息图衍射效率的方法和相应的测试系统,这种测量方法不受被测点干涉条纹方向变化的影响。同时给出了几种点阵全息防伪标识的测试结果。  相似文献   

9.
本文提出了测量点阵全息图衍射效率的方法和相应的测试系统,这种测量方法不受被测点干涉条纹方向变化的影响.同时给出了几种点阵全息防伪标识的测试结果.  相似文献   

10.
探讨实现空间滤波的新方法,分析体布拉格光栅作为空间滤波器的可行性,基于Kogelnik一维耦合波理论,讨论影响体布拉格光栅衍射效率和角度选择性的主要因素.用全息法在光致聚合物中记录了体布拉格光栅,完成了激光光束二维空间低通滤波的实验.实验结果表明:在记录材料达到饱和状态之前延长曝光时间能提高衍射效率:增大入射角度能使角度选择性提高,但由于吸收加大,衍射效率反而会有所下降.因此,体布拉格光栅用作空间滤波器时要对衍射效率和角度选择性作综合考虑.  相似文献   

11.
Results of experiments on the influence exerted by UV radiation on the height of the surface relief and on the diffraction efficiency of holographic diffraction gratings recorded on dichromated gelatin layers are reported. It is shown that the height of the surface relief substantially increases, which leads to a rise in the diffraction efficiency of the gratings to a value exceeding 25%.  相似文献   

12.
The influence of ionic liquids in photopolymerizable holographic materials was investigated extensively. The structures of ionic liquids have important effect on the properties of the materials. Although not all tested ionic liquids can improve the properties of the materials, the ionic liquids based on imidazolium, pyridium, or phosphonium with appropriate counter anions can be used as additives to increase the sensitivity, the diffraction efficiency, and the resolution of the materials in the thin hologram. Polymerizable ionic liquids have also been used as additives. Higher sensitivity, higher diffraction efficiency and higher resolution were obtained as well. These ionic liquids can carry out the photopolymerization during exposure to UV light to recording the hologram. They may assist to form a more stable hologram.  相似文献   

13.
The influence of the beam ratio between reference and object beam intensities on the characteristics of diffuse-object holograms recorded as volume phase holograms in bleached silver halide emulsion is experimentally analyzed. Measurements of the diffraction efficiency and the signal-to-noise ratio of the holograms are taken. The experimental results presented show that when the beam ratio increases, the diffraction efficiency decreases and the signal-to-noise ratio increases; these two holographic parameters behave in this way no matter what type of processing is used.  相似文献   

14.
Ogiwara A  Hirokari T 《Applied optics》2008,47(16):3015-3022
Anisotropic diffraction gratings based on a holographic polymer-dispersed liquid crystal (HPDLC) are realized by interferometric exposure using a spatial light modulator (SLM). The SLM is used in the HPDLC grating formation for anisotropic holographic recordings of two-dimensional polarization states for an incident light beam. The diffraction efficiency for P-polarization and the distinctive ratio of diffraction efficiency in P-polarization to that in S-polarization increases with the signal level applied to the SLM. The resulting volume gratings exhibit diffraction efficiency of more than 60% and a distinctive ratio of diffraction over 100. The microscopic origin of the anisotropic property is investigated by an optical polarizing microscope. The novel characteristics of the anisotropic diffraction properties of HPDLC are applied to an image reconstruction technique.  相似文献   

15.
Wang KP 《Applied optics》1995,34(29):6666-6671
Anew method for the preparation of stratified light-sensitive film is developed, and the stratified gratings (SG's) are recorded in the film. The sensitive layers on both sides of a dichromated cellulose triacetate film are produced simultaneously through chemical reaction and not with the conventional coating technique. Compared with SG's in other materials made with coating techniques, double-layer SG's in the film have, to my knowledge, the highest experimental diffraction efficiency (~54%) in addition to their having a simple recording optical system. The diffraction efficiency and the periodic Bragg selectivity of the SH in the film is given. Based on the SG's of the film, several beam splitters with 2, 3, 4, or 7 fan-outs and higher than 80% total diffraction efficiencies are realized experimentally. The advantages of this method as compared with others, such as the method based on volume holographic beam splitters, are explained.  相似文献   

16.
Downie JD  Smithey DT 《Applied optics》1996,35(29):5780-5789
Several different bacteriorhodopsin (BR) films are characterized with respect to general holographic properties. Experimental measurements include diffraction efficiency and sensitivity as functions of the writing intensity and grating frequency, hologram thermal-decay behavior, diffraction efficiency as a function of the grating tilt within the film and the modulation depth, and estimates of the refractive-index change from the diffraction-efficiency data. The films studied include those made from wildtype BR and the genetic variants D96N and D96N/T46V. The film holographic properties were found to be relatively insensitive to the grating frequency and the grating-tilt angle. The diffraction efficiency dropped off more sharply as a function of the modulation depth than did a purely linear medium, and only the hydrated wildtype film exhibited significant behavior variation with different writing intensities because of its short M-state lifetime. The maximum diffraction efficiency measured was approximately 7.5% for a hydrated D96N BR film. We also find that the hydrated BR films exhibit significantly higher refractive-index modulation than do dry films.  相似文献   

17.
The properties of a space-time light modulator comprising an a-Si:H based p-i-n diode and a nematic liquid crystal layer were studied using a holographic technique. Under certain conditions, an asymmetry of the diffraction efficiency in the +1 and ?1 diffraction orders was observed. The maximum diffraction efficiency in one of these orders may reach up to 52%, which is a record value for devices of this type.  相似文献   

18.
全息光学元件中编码与象质和衍射效率的关系   总被引:1,自引:0,他引:1  
石建川  李慎 《光电工程》1996,23(5):24-28,72
以平面波束变换为十字光束的全息光学元件为例,详细分析了HOE的相位调制、编码与解主财过程,推导出HOE的衍射效率近似解的表达式,计算出近似条件下最佳编码最大刻蚀深度值,并且对该编码方案对HOE成象质量的影响进行了分析,得出了分析的结果和结论,同时对衍射效率近似解表达式的误差进行了研究,并给出了分析结果。  相似文献   

19.
Barikani M  Simova E  Kavehrad M 《Applied optics》1995,34(13):2172-2179
The real-time hologram formation in dichromated polyvinyl alcohol films has been studied in the presence of external electron donors included in the formulation. The effect of different external electron donors on the photosensitivity and real-time diffraction efficiency of volume holographic transmission gratings has been reported. The electron donors studied were found to be detrimental to both holographic characteristics, even in small concentrations. Some parameters that influence the holographic performance are discussed, and results are given. The photochemical recording mechanism in dichromated polyvinyl alcohol in the presence and absence of electron donors is briefly discussed.  相似文献   

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