| 1. | Beam coupling factor
电子束耦合因数 |
| 2. | And we also analysis the parameters in the photorefractive two - beam coupling experiment
并对光折变二波耦合实验中一些参数选择进行了分析。 |
| 3. | Theoretical study of the intensity dependence of two - beam coupling gain coefficient in photorefractive crystals
光折变晶体两波耦合增益系数强度特性理论研究 |
| 4. | Finally , the comparison is made between the photorefractive edge - enhancement and two - beam coupling jtc
本文最后对光折变边缘增强和二波耦合联合变换相关识别进行了比较。 |
| 5. | ( 5 ) we present a photorefractive two - beam coupling jtc , in which a knsbn : cu crystal is used to a square - law converter by the nonlinear energy transfer property of the photorefractive two - beam coupling
( 5 )利用knsbn ： cu晶体作为平方律转换器件，实现实时的功率谱转换，从而实现联合变换相关识别。 |
| 6. | And the steady - state coupling response time rdecreases from 0 . 8s to 0 . 3s . but there are almost no changes in 2peak with fields applied . ( 2 ) using the characters of two - beam coupling in sbn : 61 : cr crystals under applied fields , applications in image edge - enhancement and photorefractive edge - enhancement joint transform correlator are investigated
( 2 )研究了外加直流电场作用下sbn 61 cr晶体的二波耦合特性在光学图像边缘增强以及光折变边缘增强联合变换相关器等方面的应用，讨论了外电场对光折变边缘增强及光折变联合变换相关识别效果的影响。 |
| 7. | ( 1 ) effects of externally applied electric fields on photorefractive two - beam coupling are analyzed . theoretic dependence of the intensity gain factor on applied field e0 in sbn : 60 is presented . and the experimental results obtained in two sbn : 61 : cr crystal samples with different dopant concentration show clearly that for properly applied fields , a larger f can be achieved effectively than that obtained with no field applied
由两块不同掺cr浓度的sbn 61 cr晶体得到的实验结果同时表明，适当的外电场作用能够有效提高晶体的二波耦合增益，并且，外电场的作用使晶体的响应速度大大提高，而晶体的最佳耦合角与外电场之间没有明显的依赖关系。 |
| 8. | By examining the micro mechanism of photorefractive effect , we can find that an external dc electric - field can greatly alter ( improve or worsen ) the photorefractive properties of sbnrcr . so it is important to study electric - field effects in these materials . in this thesis , the characters of beam coupling and transmission in sbn : cr crystals under external dc electric - fields are investigated theoretically and experimentally
本文依据光折变非线性光学的光波耦合理论和传输理论，对sbn cr晶体在外加直流电场作用下的光波耦合特性和传输特性进行了理论分析和实验研究，主要内容包括： ( 1 )从理论上分析了外加直流电场对光折变二波耦合增益的影响，给出了sbn 60晶体的强度增益系数随外加电场变化的理论计算曲线。 |
| 9. | ( 2 ) taking the nonlinear energy transfer property of the photorefractive two - beam coupling in the sbn : 61 crystal doped with 1000ppm cr and the knsbn crystal doped with 0 . 07wt % ce , edge - enhancement preprocessing can be achieved , which will results in the larger normalized intensity and narrower width of the correlation peaks . and the discrimination of the jtc is greatly improved
( 2 )利用sbn ： 61 ： cr晶体( 1000ppm )和knsbn ： ce晶体( 0 . 07wt )的二波耦合能量非线性转移特性，对联合变换相关器的输入图像进行边缘增强预处理，提高了相关峰的归一化强度，减小了相关峰的半宽度，从而大大提高了相关器的识别能力。 |
