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反射式窄带全息滤光片 总被引:10,自引:3,他引:7
根据耦合波理论,体积全息图有很好的滤光特性,可以作为一种窄带滤光片在实际中得到应用.本文针对峰值波长、带宽和衍射效率这三个主要参数讨论了全息滤光片的性质,提出了全息滤光片的设计步骤,并指出了全息滤光片的特点及应用前景. 相似文献
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反射式全息滤光片背景噪声的抑制 总被引:1,自引:0,他引:1
与传统的干涉滤光片相比,背景噪声高是全息滤光片的主要缺点.本文介绍了用倾斜条纹抑制全息滤光片背景噪声的方法,可以收到较好的效果. 相似文献
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中心波长121.6nm的真空紫外窄带滤光片设计和制备 总被引:3,自引:1,他引:2
采用双半波法布里-珀罗(F-P)干涉滤光片结构设计了中心波长在121.6 am的窄带滤光片,其峰值透射率为6.78%,通带半宽度为10.7 nm.通过设计、制备和测量峰值波长在217 nm的滤光片验证了设计用到的光学常数和膜厚定标都比较精确.在此基础上制备了121.6 nm的窄带滤光片,到合肥同步辐射实验室测量的结果是中心波长在120.74 nm,峰值透射率为5.94%,通带半宽度为12 nm.可以看出实际制备的滤光片和预先设计的基本吻合但还是有一定的偏差,最后对实际测量的和理论设计的偏差进行了分析. 相似文献
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从理论和实验上讨论了单腔、双腔窄带干涉滤光片中的光散射现象,结果表明:光散射主要是由干涉滤不片和腔结构引起的。当波长小球滤光片峰值波长的激光束入射到该滤光片上时,在滤光片两侧形成散射光锥,散射光的散射角等于滤光片峰值紫移到入射光波长时滤光片所转过的角度,理论计算和实验结果符合得很好。 相似文献
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新型防潮的光致聚合物全息记录材料及其应用 总被引:12,自引:2,他引:10
本文研制出一种新型兰敏的光致聚合物全息记录材料,并提出再聚会固定全息再现峰值波长的方法.这种记录材料由增感剂,引发剂,链转移剂,单体和成膜物组成.用本材料记录的全息图衍射效率可达95%以上,且能防潮,耐高温. 相似文献
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一、引言全息干涉计量的基本过程与全息记录相似,只是在记录中根据需要有时进行一次曝光(实时全息干涉法)、两次曝光(双曝光全息干涉法)和连续曝光(时间平均全息干涉法)等。它们的原理都是基于波前的干涉.这里主要讨论非漫射物的双曝光全息图的白光再现。 相似文献
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由于菌紫质样品的饱和吸收特性,在全息记录中,当记录光强大于样品的饱和光强时,全息光栅透过率随记录光相位差的分布远离余弦型,因此衍射效率的稳定值很低.菌紫质样品在红光和紫光共同作用下存在着双光束互补抑制效应,紫光可以抑制红光的透过率,提高红光的饱和光强,使记录区域由非线性区移至线性区,从而使全息光栅透过率随记录光相位差的分布变为余弦型,可以有效地提高全息衍射效率.实验证明,辅助紫光大大提高了菌紫质样品全息衍射效率的稳定值.根据此原理,建立了三光束全息光存储系统,在红光记录全息图的同时加入辅助紫光,可以使全息图衍射效率及衍射像的像质得到提高.
关键词:
菌紫质
全息存储
衍射效率
饱和吸收 相似文献
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由一束球面波和一束平面波或者两束球面波干涉所形成的体全息光栅,由于其光栅矢量在全息图体积内是随位置的变化而变化的,所以被称为非周期型的体光栅。主要研究了用于体全息三维成像系统的非周期体光栅的深度选择特性。根据叠加的原理,将非周期体光栅看作多个固定周期的基元体光栅的叠加,结合耦合波理论分析非周期体光栅的衍射特性。采用这一方法,利用Matlab软件模拟,研究了两束记录光夹角对所记录的非周期体光栅深度选择性的影响和在两束记录光夹角相同时,球面参考光体全息成像系统及平面参考光体全息成像系统深度选择性的差别,最后在光折变晶体材料中进行非周期型和周期型体光栅的记录和再现,对模拟结果进行了实验验证。 相似文献
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A. Emoto A. Tashima M. Kondo M. Okada S. Matsui N. Kawatsuki H. Ono 《Applied physics. B, Lasers and optics》2012,107(3):741-748
Anisotropic diffractive gratings formed by birefringent molecular alignment are fabricated by a holographic technique using a photo-cross-linkable liquid crystalline copolymer (PLCCP). Depending on the exposure energy used for holographic recording, bright or dark regions of the interference fringe can be chosen for the molecular-aligned region, analogous to positive- and negative-type photoresist processing in photolithography. In conjunction with simultaneously generated surface relief gratings, the anisotropic refractive index modulation inherent in the PLCCP film exhibits different diffraction properties depending on the incident beam polarization. The anisotropic refractive index grating profiles are quantitatively presented for two cases determined by the exposure energy, based on the Fourier analysis of diffractive optics. The selection of different grating formations selected by varying only the exposure energy could provide a strategy for the fabrication of functionalized diffractive optical elements. 相似文献
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Yanjie Zhang Zifeng Lu Xuefeng Deng Yichun Liu Yingying Zhao 《Optics Communications》2003,220(4-6):289-295
Holographic gratings were optically recorded by two beams from a He–Ne laser operating at 632.8 nm in poly (methyl methacrylate) (PMMA) film containing push–pull azo dye. The holographic characteristics of the recorded gratings were dependent on the polarization direction of the recording beams and the relationship between the diffractive signals and the power density of recording beams was investigated. The formation of holographic gratings accompanied by 532 nm (double-frequency of Nd:YAG laser) irradiation was studied in detail. It was found that the effect of 532 nm laser to the holographic grating lay in two aspects. The acceleration effect of 532 nm laser to the formation of holographic grating is predominant when the power density of 532 nm laser is low. While at relatively high power density of 532 nm laser, the erasure is the main factor to the holographic grating. Moreover, the holographic grating was probed by 532 nm laser at low power density and the dependence of the first order diffractive signal on the recording beam power density was also presented. 相似文献
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变间距全息光栅具有自聚焦和消像差功能,是高分辨率光谱仪与同步辐射单色器中的重要元件。研究了使用平面等间距光栅产生非球面波,记录平面变间距全息光栅的方法。根据几何光学的光线追迹理论,推导了光栅参量的四阶解析表达式。并基于费马原理,提出了记录光路的光线追迹数值算法。应用所推导的光栅参量四阶表达式,仿真设计了变间距全息光栅。通过合理选择记录参量,可以避免光栅基底受到零级及高阶衍射光场的影响。设计结果表明,理论光栅线密度与要求值相当符合;经光线追迹数值算法验证,解析表达式的展开误差在整个记录区域内小于1.5线;考虑到实际加工工艺允许误差,使用辅助光栅的记录光路对记录参量的误差并不敏感;设计实例证明了解析表达式的有效性,以及使用辅助光栅的记录光路的优越性。 相似文献
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数字微镜器件在视频全息中的应用 总被引:6,自引:2,他引:4
为研究数字微镜器件在视频全息中的应用,探讨了基于数字微镜器件的全息编码方法。基于数字微镜器件的微观物理结构,讨论二维离散微镜像素结构、开态微镜列的闪耀光栅特性和脉宽调制的微镜偏转工作原理。将数字微镜器件分辨力、微镜尺寸、间隔、旋转角度、参考光入射角以及衍射条件等因素结合到计算全息编码中,提出干涉面抽样方法、相位补偿技术和无偏置二元全息编码方法,使产生的计算全息图适应数字微镜器件独特的空间光调制特性和计算视频全息的要求。实验表明,该方法调整了重构物光波的衍射方向,集中了衍射光在重构像中的分布,增加了成像清晰度和光能有效利用率,提高了全息编码效率。 相似文献
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传统方格型二维光栅与周期性缝隙阵列的组合薄膜结构具有雷达和光学波段双带通的电磁特性. 但由于其杂散光能量集中分布而严重制约它在高精度探测以及成像领域中的应用. 本文提出了一种全新的组合薄膜结构, 即由满足一定约束条件的圆孔型二维光栅和十字缝隙阵列构成. 基于Fraunhofer衍射理论建立组合薄膜结构标量衍射模型, 通过对比两种组合薄膜结构的衍射光分布, 理论分析与实验测试均表明: 圆孔型光栅与十字缝隙阵列组合薄膜结构不仅能够提高其光学透过率, 而且还使其杂散光分布均匀, 降低了其杂散光总比率, 从而有效抑制杂散光, 进一步增强了二维光栅与周期性缝隙阵列组合薄膜结构在实际光学系统中的可靠性.
关键词:
二维光栅
组合薄膜结构
衍射光强
杂散光 相似文献
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L. Nedelchev D. Ivanov N. Berberova V. Strijkova D. Nazarova 《Optical and Quantum Electronics》2018,50(5):212
Azopolymers are one of the most efficient materials able to record the polarization state of light. They have numerous applications, such as data storage and diffractive optical elements with unique polarization properties. An essential parameter for each diffractive element is its diffraction efficiency η. In order to optimize the recording conditions and obtain high-efficient polarization holographic gratings, in the present work we study the dependence of the diffraction efficiency on the recording angle and thickness of a series of azopolymer layers. Three recording angles are used ??10°, 20° and 30° and three series of thin films with thicknesses 470, 850 and 2400 nm from the water-soluble azopolymer PAZO. The gratings are inscribed by two plain waves with left and right circular polarization from a He-Cd gas laser (442 nm). The diffraction efficiency of the gratings is probed with a right hand circularly polarized beam from a probe laser with wavelength 635 nm. The kinetics of diffraction efficiency η(t) in the +?1 diffraction order are presented and compared. Our experimental results indicate that highest diffraction efficiency (more than 40%) is obtained for the sample with thickness 2400 nm and for recording angle 10°. As the holographic recording in azopolymers is usually accompanied by formation of surface relief gratings, the surface topography of the recorded samples is also investigated by atomic force microscopy. 相似文献
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It is established that DNA films sensitized by organic dyes (for example, acridine orange), subjected to pulsed excitation in the dye absorption band, allow for several types of time-dependent holographic recording. Dynamic holographic gratings on the dye triplet states and thermal and relief-phase holographic gratings of nondestructive type have been recorded. The efficiency and lifetime of these gratings depend strongly on the concentration of dye, the type of its bonding with the biopolymer, and the recording-pulse energy. High-efficiency relief holographic gratings formed due to the structural transformations occurring in the biopolymer matrix when the energy of recording laser pulses dissipates into heat spontaneously and completely (or almost completely) disappear with time at room temperature. Some data on the distribution of acridine orange molecules over binding sites in the DNA matrix are obtained. 相似文献