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1.
An experimental study of variation of sensitivity with recording and sensitizing intensities in two-center recording is presented. The experimental results are in good agreement with the theoretical predictions. It is shown experimentally, for what is to our knowledge the first time, that the sensitivity is a function of the ratio of recording to sensitizing intensities and not the absolute intensities. Also, the ratio of recording to sensitizing intensities should be small to obtain high sensitivity values. We also report the highest sensitivity (S=0.15 cm/J) that has been achieved to date for a LiNbO3:Fe:Mn crystal. 相似文献
2.
The near-infrared nonvolatile holographic recording has been realized in a doubly doped LiNbO3:Fe:Rh crystal by the traditional two-center holographic recording scheme, for the first time. The recording performance of this crystal has been investigated by recording with 633 nm red light, 752 nm red light and 799 nm near-infrared light and sensitizing with 405 nm purple light. The experimental results show that, co-doped with Fe and Rh, the near-infrared absorption and the photovoltaic coefficient of shallow trap Fe are enhanced in this LiNbO3:Fe:Rh crystal, compared with other doubly doped LiNbO3 crystals such as LiNbO3:Fe:Mn. It is also found that the sensitizing light intensity affects the near-infrared recording sensitivity in a different way than two-center holographic recording with shorter wavelength, and the origin of experimental results is analyzed. 相似文献
3.
Youwen Liu Liren Liu De'an Liu Liangying Xu Changhe Zhou 《Optics Communications》2001,190(1-6):339-343
Nonvolatile photorefractive gratings have been recorded in LiNbO3:Cu:Ce crystals by using a He–Ne laser (633 nm) for recording and an argon ion laser (458 nm) for sensitizing. The sensitizing light increases the recording sensitivity by a−bexp(−Is/c) and saturation behavior will appear with high enough intensity of sensitizing light. The recording light increases the slope of η1/2 as a function of time during the initial stages of hologram formation by sublinear Ixr (x<1) and thus the recording light decreases the recording sensitivity. The dependence of saturation diffraction efficiency on the intensities of the recording and sensitizing light shows that there is a maximum dynamic range of the recording process. 相似文献
4.
P. Cheben M. L. Calvo F. del Monte O. Martínez-Matos J. A. Rodrigo 《Optics and Spectroscopy》2007,103(6):855-857
The advances in the sol-gel holographic recording materials, namely in the photopolymerizable compositions and photorefractive
glasses, are reviewed. A new sol-gel holographic material is also discussed that exploits diffusion of a high-refractive-index
MA:Zr complex, with the refractive index modulation of n ∼ 10−2 and negligible scattering.
The text was submitted by the authors in English. 相似文献
5.
Photopolymer holographic recording material 总被引:1,自引:0,他引:1
6.
M. Weber F. Rickermann F. Abbing G. von Bally 《Applied physics. B, Lasers and optics》1999,68(5):1069-1072
A holographic double-exposure interferometer for quasi real-time analysis is realized, utilizing a photorefractive BTO:Cd
crystal for hologram recording. Heating of the crystal reduces the time required to reach the steady-state working situation.
Light-induced absorption losses are reduced by heating as well. Additionally, the diffraction efficiency is increased by this
method. A sixfold increase in the light intensity of the reconstructed interferogram is achieved.
Received: 2 December 1998 / Revised version: 28 January 1999 / Published online: 7 April 1999 相似文献
7.
We have observed quasinondestructive holographic storage with a continuous-wave laser at lambda = 532 nm in near-stoichiometric LiNbO3 doped with Tb and Fe. This crystal showed an exceptionally long grating decay time and also exhibited a fast color change upon exposure to ultraviolet (UV) light. It was demonstrated that the grating recorded from the UV-exposed, colored state can be continuously read out over 9 h at a reading intensity as high as 8 mW/cm(2). In addition, the written grating could be easily erased with UV illumination which returned the crystal back to the original colored state. 相似文献
8.
9.
Localized holographic recording in doubly doped lithium niobate 总被引:1,自引:0,他引:1
Persistent holograms are recorded locally with red light in a LiNbO>(3) crystal doped with Mg and Fe. Selective erasure is realized by use of a focused UV sensitizing light. We demonstrate the recording of 50 localized images as well as selective erasure in a 4 mm x 4 mm x 4 mm crystal. A comparison of the total recording time for M holograms obtained with the conventional distributed-volume recording and the localized methods is presented. 相似文献
10.
We report what is to our best knowledge the first holographic recording in photosensitive polymer optical fibers by guided beams. The fibers are made of poly(methyl methacrylate) doped with Disperse Red 1 dye. We also demonstrate what we believe is the first recording of Fourier-transform images in these fibers. 相似文献
11.
Holograms may be recorded in photorefractive LiNbO3:Cu with pulsed infrared light (wavelength =1064 nm, Q-switched Nd:YAG laser), if the crystals are previously or simultaneously illuminated with a green (=532 nm) light pulse. We study refractive index changes and time constants of as-grown and thermally treated crystals with different copper concentrations. A model explaining this effect is discussed. 相似文献
12.
A new polarized-light-controlled holographic recording based on the optical enhancement/restraint of self-diffraction has
been demonstrated in an azobenzene-doped polymer film. It is found that a continuous variation of the polarization status
as well as of the intensity of the pumping light results in a continuous variation of self-diffraction efficiency. The mechanism
originates from the photo-induced anisotropy and polarization-dependent absorption. Both positive and negative replicas of
an incident image were presented in real time by means of this incoherent–coherent optical conversion technique.
Received: 30 March 2000 / Revised version: 28 September 2000 / Published online: 27 April 2001 相似文献
13.
Volume holograms are stored in KCl:Na crystals using the photoinduced reorientation of FA centers. The dependence of the diffraction efficiency on the directions of polarization of the recording and the reconstructing waves are shown. Experimental results are in good agreement with the calculated curves, predicted by the theory. 相似文献
15.
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
16.
Two-dimensional (2D) polarization patterns are achieved by the interference of two pairs of beams with perpendicular planes of incidence and orthogonal polarizations (i.e. linear or circular). In both cases, imposing a phase shift of π/2 between consecutive beams contains the amplitude modulation of the optical field in the superposition region and, thus, pure 2D polarization patterns are created. The recording of these interference fields in a polarization-sensitive material, namely an amorphous azopolymer, creates reconfigurable 2D periodic microstructures with peculiar diffraction properties. 相似文献
17.
全息记录新材料:重铬酸盐—三醋酸纤维素酯 总被引:1,自引:1,他引:0
本文报道一种新的全息记录材料:重铬酸盐-三醋酸纤维素酯组成的感光介质。这种全息材料具有较强的实时效应,较高的衍射效率,良好的抗潮能力和环境稳定性等特点。文中分析了这种材料的感光成象机理,通过实验研究了其全息记录特性,给出了实验结果。 相似文献
18.
Nonvolatile holographic recording is performed with green light in LiNbO3:Ce:Cu crystals. The refractiveindex change and the recording sensitivity are times better than those obtained by recording with red light,and higher optical fixing efficiency is obtained. Correspondingly, theoretical investigations are given. 相似文献
19.
O. Momtahan G.H. Cadena A. Makhmalbaf A. Adibi 《Applied physics. B, Lasers and optics》2008,90(3-4):519-525
In this paper, we report the observation of electron tunneling during two-center recording in LiNbO3:Fe:Mn doped with high Fe concentration. Unlike tunneling in the singly doped lithium niobate that erases the hologram, the
effect in two-center recording can improve the diffraction efficiency of the hologram after the recording while it is kept
in the dark. A detailed study of this effect in LiNbO3:Fe:Mn is presented both theoretically and experimentally. We show that the hologram strength may increase or decrease due
to tunneling, depending on the experimental condition of recording.
PACS 42.40.-i; 42.70.Ln; 42.40.Lx 相似文献
20.
C.S. Vikram 《Optics Communications》1973,7(4):347-348
Except for the extreme positions, a vibrating object passes twice through a position in each vibration cycle. It is suggested that this fact can be used to reduce the recording time during the pulsed illumination in stroboscopic holographic interferometry by providing two light pulses per vibration cycle for a given subject position. 相似文献