Study on self pumped phase conjugation and four wave mixing in a BaTiO_3 photorefractive crystal.

BaTiO_3光折变晶体自泵浦相位共轭和四波混频研究

基本信息

批准号：
06650379
负责人：
MISHIMA Teruhito
金额：
$ 1.09万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650379/
关键词：
Optical phase conjugation Self-pumped phase conjugation Four wave mixing Photorefractive crystal Response time BaTiO_3 crystal Self-pumped four wave mixing

项目摘要

The location and profile of phase conjugate image produced by Gaussian beam pumped DFWM are studied. The equation describing the dependence of the conjugate image location and the transverse magnification factor on the gaussian beam parameters are derived. The reconstructed images of distorted probe object are calculated numericallyand it is found that the quality of the image is limited by the curvature, as well as, by the spot size of the Gaussian pump beams.Ordinary Self-Pumped Phase Conjugator (SPPCM) is demonstrated with use of a BaTiO_3 photorefractive crystal and analyzed. The comparison between the experiment and the theoretical analysis makes it possible to control the reflectivity of the SPPCM.Self-Pumped Four Wave Mixing (SPFWM) in a single BaTiO_3 crystal is demonstrated, which means that a simple phase conjugator with two incident beams is realized. At first, the conjugator was unstable and it is found that refractive index gratings were produced at a same region in the crystal and they sompete with each other. The competition is the origin of unstableness, so that separating the two index gratings leads to stable operation of SPFWN.The reflectivity and the response time of SPFWM are measured and found that it is as fast as ordinary four wave mixing and is faster than SPPCM by the order of two.As a result of this study, SPFWM in a BaTiO_3 crystal which uses phase conjugate beam as one of the pump beams which is generated by SPPCM in the same crystal is realized with rather simple optical system. It is found that the response of the SPFWM is as fast as ordinary four wave mixing.

研究了由高斯梁泵送DFWM产生的相结合图像的位置和轮廓。描述了共轭图像位置的依赖性和横向放大因子对高斯光束参数的方程式。在数值上计算了扭曲的探针对象的重建图像，发现图像的质量受曲率的限制，以及由高斯泵梁的斑点大小。使用BATIO_3光致热晶体并进行了分析。展示了实验中的实验和理论分析之间的比较，可以控制单个BATIO_3晶体中SPPCM的反射率。。起初，偶联器是不稳定的，发现折射率是在晶体中同一区域产生的，它们彼此相处。竞争是不稳定的起源，因此分开两个索引光栅会导致SPFWN的稳定操作。衡量SPFWM的反射率和响应时间，并发现它的速度与普通的四波混合一样快，并且比SPPCM比SPPCM更快。两者的顺序。作为这项研究的结果，在BATIO_3晶体中，SPFWM使用相结合束作为SPPCM在同一晶体中生成的泵梁之一，它使用相当简单的光学系统实现。发现SPFWM的响应与普通四波混合一样快。