共查询到20条相似文献,搜索用时 984 毫秒
1.
高性能体全息光栅是全息波导的重要耦合元件,角带宽小、平均衍射效率不高是制约体全息光栅性能的重要因素。以不对称倾斜记录为出发点,设计并制备了大角带宽高衍射效率的体全息光栅。首先讨论在横电模式光和横磁模式光下体全息光栅的记录参数与其衍射效率的关系,找到平均衍射效率较高的记录参数范围,随后进一步分析在此范围内的记录参数与体全息光栅的角带宽的关系,从而确定获得大角带宽高衍射效率体全息光栅的最佳记录参数。实验结果表明:在参考光入射角度为25°、信号光入射角度为30°时,制备的体全息光栅的角带宽达到±14°,衍射效率为82%。 相似文献
2.
报道了甲基橙偶氮染料掺杂的聚乙烯醇薄膜材料在Ar^+激光488.0nm线辐照下,用正交线偏振的632.8nm光作为写入光,通过旋转样品,在同一光斑内形成多个取向不同的相位光栅,实现了多重全息存贮的实验结果。在三重图象的存贮中,通过控制每次的写入时间、得到了三个均匀明亮的衍射图像,其平均衍射效率为0.1%。 相似文献
3.
一种新型偶氮化合物中的高效率实时全息光栅的实验研究 总被引:1,自引:0,他引:1
合成了一种新的含偶氮基的三元共聚物,由于在主链中链接柔性基团,使其具有相对较低的玻璃化温度,在633nm处光感生双折射δn值可达10^-3量级。实验上获得了几个乃至几百微米厚的具有高光学无效性的薄膜,在633nm波长处写一息光栅的实时单光束衍射效率可达10%以上。 相似文献
4.
5.
6.
本文利用重铬酸盐明股作为记录介质,采用双曝光记录工艺,试制了反射式双峰值波长的全息滤光片.这种全息滤光片双峰值衍射效率可达87%,带宽小于10nm,是一种新的具有潜在应用前景的全息光学元件. 相似文献
7.
通过化学反应,在三醋酸纤维素睛基的正反两面同时生成具有感光活性的光敏层的方法,获得了一种具有叠层光敏性的全息记录软片:重铬酸盐-三醋酸纤维素酯。由该软片记录的叠层体积全息光栅,具有迄今为止,最高的一级实验衍射效率(54%)。 相似文献
8.
9.
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
10.
11.
A.E. Korolev 《Optics & Laser Technology》1996,28(4):277-284
Problems of dynamic hologram recording on resonant absorption lines of alkali metal vapour are discussed. Light beams and media parameters are determined that are necessary for hologram recording with usable efficiency. The effects of thermal atomic motion and the radiative transport of excitation influence on the spatial frequency transfer function of two-level media are investigated. Results of hologram recording in vapour of Rb (780.0 nm) and Cs (852.1 nm) using low-power CW-lasers are presented. Transmission holograms in the volume media and reflection holograms near the boundary of the resonant vapour and the dielectric are compared. For transmission holograms the advantage of collinear read-out when using pure vapour in comparison with a counterpropagating read-out is shown, and this makes it possible to achieve higher values of hologram efficiency over a wide range of atomic density. It is shown that reflection hologram recording is characterized by higher resolution, as compared with hologram recordings in the volume of extended media. Problems of metal vapour hologram usage for laser parameter control are discussed. The feasibility of holograms in Cs-vapour usage as a spectral-selective real-time feedback element in a semiconductor laser external cavity is shown. 相似文献
12.
Shang Sun Zhenxing Zhou Chen Zhang Wenhong Yang Qinghai Song Shumin Xiao 《Annalen der Physik》2018,530(3)
Wide‐bandgap material based all‐dielectric metasurfaces have been ideal platforms for the realization of arbitrary phase control in visible spectrum. While TiO2 metasurfaces are very promising in broadband and high‐efficiency anomalous transmission, meta‐hologram, and meta‐lenses et al., the current realizations are strongly dependent on the sophisticated fabrication technique to fabricate TiO2 nano‐pillars with aspect ratio > 10. Herein we experimentally demonstrate a much simpler approach to realize efficient phase control of visible light. By exploiting TiO2 nano‐blocks as meta‐atoms on a ground metal plane, we find that TiO2 metasurface with aspect ratio around 1‐1.5 is good enough to produce phase changes covering ‐π to π and high reflection efficiency simultaneously. Based on the phase control of the meta‐reflectarray, anomalous reflection with a ratio between anomalous reflection and normal reflection ~ 74/26 have been experimentally realized using a combination of typical electron‐beam lithography, electron‐beam evaporation, and a simple lift‐off process. Similarly, high performance TiO2 metasurface in form of hologram has also been demonstrated for red (633 nm), green (520 nm), and blue (445 nm) wavelengths. We believe this research shall route a new way to cost‐effective all‐dielectric metasurfaces and advance their applications in encryption, anti‐counterfeiting, and wearable displays. 相似文献
13.
二步法大景深反射全息图 总被引:1,自引:0,他引:1
以开拓反射全息图的景深表达能力为目的,从反射全息图的共轭物像关系出发,利用反射全息图的均匀介质耦合波理论和布拉格条件,对其白光再现像模糊作了具体的分析和讨论,得到色模糊和线模糊的表达式.指出反射全息图上不同各点对任意白光再现像点的色模糊和线迷糊的影响均存在差异,给出反射全息图白光再现像的景深表达式.实验利用二步法制作了一张景深为83 cm的反射全息图,与大景深彩虹全息图再现像相比,其再现像的立体感更加强烈.理论分析和实验结果表明,光源的再现角度和观察距离对反射全息图的再现像景深大小影响显著.在再现光垂直于反射全息图平面照明情况下,反射全息图具有最好的景深表达能力. 相似文献
14.
15.
16.
The formation of spontaneous periodic structures in thin AgCl-Ag films subject to the continuum (λ≈450–700 nm) in the case of rotation of the plane of polarization with the help of crystalline quartz is studied. The periodic structures are formed due to the excitation of waveguide TE0 modes in spontaneous Rayleigh scattering of radiation with a wavelength λ incident on the film. The structure periods are smaller than λ and vary in proportion with λ. After special treatment of the irradiated sample (fixing and deposition of an Al layer), periodic structures form a thin reflection hologram capable of reproducing the direction of linear polarization, the angle of optical rotation, and the color of the spectrum recorded. The study of diffraction patterns and small-angle scattering from small portions of a hologram, which were exposed to light with various wavelengths in the recording process, with the help of a probing UV beam (λp=337 nm), made it possible to reveal special features of the manifestation of Rayleigh and Wood anomalies associated with the domain structure of PS. 相似文献
17.
18.
Daisuke Sakai Kenji Harada Shun-ichi Kamemaru Daisuke Barada Fuminobu Sato Takashi Fukuda 《Optical Review》2009,16(3):335-338
We propose a method of hologram recording in a glass plate by corona charging. The holographic recording materials used in
this study are conventional soda-lime glass and azobenzene polymer film. A Fourier transform hologram on an azobenzene polymer
film coated on the glass plate is recorded in the glass plate by corona charging. After removing the polymer film, the hologram
recorded in the plate can be reconstructed using a visible-wavelength laser beam. The first-order diffraction efficiency of
the hologram at a wavelength of 532 nm is 0.03%; the efficiency depends on the depth of the surface relief structure on the
azobenzene polymer film and the corona-charging time. The hologram recorded in the glass plate has high environmental resistance. 相似文献
19.
在室温下,二价稀土离了 杂的LiBaF3:Eu^2 粉末样品中,Eu^2 的发射呈现双峰结构,有一峰值波长约为410nm的宽峰,对应于Eu^2 的5d-4f跃迁,以及另一峰值波长约为360nm的窄峰,对应于Eu^2 的4f-4f跃迁。在50-400nm波长范围,测量了样品的反射光谱,并利用Kramers-Kroenig关系,计算了吸收光谱。从吸收光谱中,可以看到在102nm处有明显的吸收边,得到LiBaF3材料的禁带宽度Eg约为12.1eV。在高能端有53.4,59.4,65.3,69.2和76.5nm的吸收峰,它们对应于Ba^2 的5p电子和F的2p电子芯能级之间的跃迁,在低能量的183.4nm处,有很明显的吸收峰,推测这对应于本征缺陷的吸收。更低能量的吸收峰,则对应于禁带中的一些杂质能级,在未经紫外光或X射线辐照之前,用长波长(>450nm)光激发LiBaF3:Eu^2 粉末样品,可以观测到Eu^2 离子的360nm和410m发光,亦表现出光激励发光特性。 相似文献
20.
The dependence of the maximal diffraction efficiency of a volume reflection hologram recorded in a cubic optically active
photorefractive piezocrystal on the crystal thickness is investigated. The theoretical analysis is fulfilled on the basis
of the coupled wave equations in a static grating approximation taking into account the linear electro-optic, inverse piezoelectric,
and photoelastic effects. The optimal cuts of the crystals with various thickness for which the maximal diffraction efficiency
of the reflection hologram can be attained are determined. It is shown that the optical activity of the crystal is responsible
for a variety of the optimal cuts corresponding to different crystal thicknesses. Effect of the crystal on the dependence
of the maximal diffraction efficiency of the reflection hologram on a crystal cut is discussed. 相似文献