曙红敏化重铬酸盐明胶光声光谱的研究

用曙红敏化重铬酸盐明胶全息记录材料，用光声光谱技术测定了这种材料的光能吸收光谱，实验的结果表明，曙红是一种新的有价值的重铬酸盐明胶光谱增感染料，可以在５１４．５ｎｍ处形成强吸收峰，这对于记录彩色全息图和制作全息光学元件是有利的，光声光谱技术在全息记录材料的光谱增感与光化学过程的测量中，是一种极其灵敏又十分有效的方法。     

红敏重铬酸盐明胶增感的新方法

对普通红外敏明胶感光度低的原因进行了分析。在此基础上提出了多敏感中心的新增感方法。文中对这种方法的增感机理从光化学角度进行了分析，并用红外光谱和对比实验进行了验证。最后还对这种增感方法的实际效果进行了考察。     

用亚甲蓝敏化的重铬酸铵明胶全息图的工艺研究

研究了用亚甲蓝敏化的重铬酸铵明胶（ＭＢＤＣＧ）全息图的工艺，提出了提高脱水温度并将急剧脱水过程改为逐步脱水过程的制作方法，提高了衍射光栅的角度（波长）灵敏度，避免了在制作过程中明胶发生霜现的现象。研究了明胶中重铬酸铵和亚甲蓝的浓度、曝光量和脱水温度对全息图像衍射效率的影响。实验结果能较好地符合由Ｋｏｇｅｌｎｉｋ的耦合波理论导出的理论值。     

Holograms recorded with red light in dye sensitized dichromated gelatin

We have found that phase holograms can be recorded with He—Ne laser light in dye sensitized dichromated gelatin. This material has excellent resolution, and refractive index changes up to 0.02 have been observed. The sensitivity of dye sensitized dichromated gelatin at 633 nm is about five times less than of dichromated gelatin at 488 nm.     

Kinetics of hologram recording on chromated gelatin using the diode-laser radiation

The hologram recording on the dichromated gelatin layers using the radiation of a diode laser and a diode-pumped solid-state laser is investigated. The recording on dry and self-developed dichromated gelatin layers is experimentally demonstrated. Various recording regimes are studied for wavelengths of 0.53 and 0.66 μm.     

Dichromated gelatin for volume holographic recording with high sensitivity. Part II

A method is described to raise the sensitivity of dichromated gelatin layers by hardening them before exposure, with compounds binding not the carboxyl but the amino groups of the gelatin molecules. The experiments showed a tenfold increase in the light sensitivity of the layers.     

Influence of Post－baking and Delaying Processes on Dichromated Holograms：Their Mechanism

ＩｎｆｌｕｅｎｃｅｏｆＰｏｓｔ－ｂａｋｉｎｇａｎｄＤｅｌａｙｉｎｇＰｒｏｃｅｓｓｅｓｏｎＤｉｃｈｒｏｍａｔｅｄＨｏｌｏｇｒａｍｓ：ＴｈｅｉｒＭｅｃｈａｎｉｓｍＷＡＮＧＧｕｏｐｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＷｕｈａｎＵｎｉｖｅｒｓｉｔ...     

Post-processing of developed dichromated gelatin holograms

A method for salvaging over or under exposed dichromated gelatin holograms is developed. The technique allows for readjustment of the refractive index modulation of rejected holograms to a desired level.     

重铬酸盐明胶全息干板研制

本文详细论述重铬酸盐明胶全息干板的特性、光化感光机理、制作方法、注意事项和存在的问题等。给出多年实验摸索的经验总结。     

从微观化学结构分析全息图的环境稳定性

本文根据实验结果,比较分析分别用两种不同重铬酸盐全息材料(重铬酸盐明胶和无明胶重铬酸盐全息软片)制作的全息图的内部光化学反应产物(螯合物)的微观化学结构,对二者在抗潮能力和环境稳定性方面表现出的显著差异作了比较合理的理论解释。首次提出全息图具有优良的抗潮能力和环境稳定性的根本原因在于螯合物(?)部化学结构的完全对称的观点。     

The Application of Heat Treatment in the Formation of Relief-Phase Holographic Structures on Dichromed Gelatin

Optics and Spectroscopy - A new method of formation of relief-phase holographic structure on dichromated gelatin (DCG) layers has been proposed. The method is based on two types of alternative...     

Development of a mirror backed volume phase grating with potential for large aperture and high damage threshold

The present paper proposes a new grating concept by which a volume phase grating is placed on top of a dielectric mirror stack. Instead of using a multilayer dielectric grating, wherein the uppermost layer of a thin film mirror is etched to create the desired binary phase grating we suggest to have an upper grating layer of a lower density gelatin-based volume phase grating in either sol–gel or dichromated gelatin. The key benefit is the elimination of the etching step which is the limiting factor in the production of large aperture gratings. We have investigated designs for s- and p-polarization as well as the necessary chemistry that is needed to achieve the required index modulations. Damage testing on dichromated gelatin and aerogel was performed and diffraction efficiencies for various prototypes were measured.     

衍射光学器件光线追迹公式的实验验证

本文介绍了一种衍射光学器件光线追迹的方法，并给出了计算公式。作为验证，在实验室里制作了具有连续相位的体全息器件，将其实际再现光斑与计算点列图进行比较。构造透射体全息片的物光为离轴的球面波，始于轴外点Ａ（０，１３２ｓｉｎ８°，－１３２ｃｏｓ８°），参考光为平面光束，其与Ｚ轴夹角为１７°。激光器采用氩离子激光器（Ｓｐｅｃｔｒａ－ｐｈｙｓｉｃｓＭｏｄｅｌ２０２０），波长４８８ｎｍ；干板感光胶为重铬酸明胶（ＤＣＧ），胶层厚为１５μｍ；通光口径３０ｎｍ。测试时把全息片放在干板的位置。挡住物光，让再现光以和参考光路相同的路径平行入射到全息片上，在全息片后垂直光轴放置毛玻璃片，平行光轴移动毛玻璃片，可观察到－１级衍射光的变化。在距离原点的距离分别为（ａ）４０ｍｍ，（ｂ）７０ｍｍ，（ｃ）８７ｍｍ，（ｄ）９５ｍｍ的地方用ＣＣＤ拍摄了衍射光的形状，与程序计算的点列图在形状和大小上都吻合     

高性能红敏重铬酸盐明胶及其分子改性抗潮方法

研究一种高衍射效率、高感光度亚甲基兰红敏重铬酸盐明胶（ＭＢＤＣＧ）全息记录材料。用这种材料记录的全息图经分子改性、脱去明胶的强吸潮基团，获得在高湿度环境中稳定的高衍射效率的ＭＢＤＣＧ全息图     

反射式全息滤光片的带宽和考虑记录介质吸收后的衍射效率

用重铬酸盐明胶底片可制成反射式全息滤光片,本文导出了这种滤光片的带宽理论公式,在修改的耦合波理论的基础上,导出了与记录全息过程中吸收系数有关的峰值衍射效率公式,由此,提出了对这种滤光片的制造和使用的建议.     

Achromatic reconstruction of femtosecond holograms in the planar optical waveguide

Holograms were recorded by 30 fs laser pulses in 20 microm film of dichromated gelatin on the polished quartz substrate and reconstructed in the waveguide mode. The geometric-optical regime of waveguide hologram reconstruction was obtained: the direction of the reconstructed beam was observed to be independent on the reconstructing wavelength within the hologram spectral selectivity band. We discuss the possibility of producing achromatic waveguide optical elements containing only a few periods.     

一维全息光子晶体的带隙结构研究

对一维全息底片运用光子晶体的概念,利用平面波展开法和传输矩阵法,数值计算了介电常数余弦调制的一维全息光子晶体结构的带隙,主要针对全息记录材料为重铬酸盐明胶时设置了计算用参数,计算结果表明对于折射率周期性渐变的一维全息晶体结构同样具有一般光子晶体的带隙,进而研究了带隙的特点.发现禁带宽度随着所使用的记录介质折射率的增加而减小,随着介质折射率调制的增加而增加;带的位置随着介质折射率的增加而移向低频,随着介质周期长度的增加移向低频,折射率调制的改变基本不影响禁带位置.     

Dichromated gelatin for volume holographic recording with high sensitivity. Part I

Dichromated gelatin would be the most suitable irreversible medium for holographic recording but for its low sensitivity. The efficiency of the photoinduced reduction of the chromium ion increases considerably if superfine grains of silver halide crystals are present in the layer. The light sensitivity achieved is about 10 times better than that of dichromated gelatin layers, obtained and processed in the conventional way.     

提高重铬酸盐明胶全息图环境稳定性的一种新方法

在明胶水悬浮液中加入少量聚乙烯醇及必要的添加剂,经重铬酸铵敏化后曝光制作Lippmann全息图.实验表明,与用传统方法制作的重铬酸盐明胶全息图相比,其环境稳定性有了明显的提高,本文还讨论了聚乙烯醇等物质的加入所起的作用及这种全息图环境稳定性提高的机理.     

Dichromated gelatin and its importance for optical hologram recording

A long-lasting development in the area of holographic recording materials has shown that gelatin, a natural material, can be used as a medium for the holographic recording. Dichromated gelatin is a result of the effort to obtain phase holographic optical elements with high diffraction efficiency. This paper gives overview of its importance for holography, difficulties with its treatment, possibilities of its utilization, optical properties, and explains chemical processes being under way in gelatin from its exposure to fixing. Our experience with the formation of holographic optical elements into dichromated gelatin is mentioned. This work was supported by the project LN00A015 of the Ministry of Education of the Czech Republic.