光子学报, 2011, 40 (1): 73, 网络出版: 2011-03-08
检偏角对水中光脉冲后向散射特性的影响
Influence of Analyzer Angle on Backscatter Characteristic of Optical Pulse in Water
摘要
针对水下光脉冲后向检测装置中偏振检测系统的检偏角对激光脉冲后向散射特征的影响,首先运用光波在散射面的反射和折射理论,定性分析了偏振光在水中传输时,由于散射引起的退偏效应;然后采用线偏振激光脉冲作为光源,实验探测不同检偏角时的光脉冲后向散射信号;最后通过对比不同检偏角时,激光脉冲后向散射信号前沿位置、后沿位置、脉宽、峰值、形状和面积等特征的统计平均值,分析检偏角对激光脉冲后向散射特性的影响.实验结果表明:随着检偏角的增大,光脉冲后向散射信号脉宽变窄,形状变得平缓,峰值和面积减小;信号前沿和后沿位置向后移动,前沿的移动幅度远大于后沿;并且偏振检测系统对近处水域后向散射信号的滤除越明显.
Abstract
In order to study the influence of the analyzer angle of polarization detection system on the backscatter characteristic of optical pulse in the backward detection device of optical pulse underwater, firstly, the depolarization by scattering was analyzed qualitatively when polarized light travelled in the water using the reflection and refraction theory on the scattering interface. Secondly, with linear polarized laser pulse as incident light, backscatter signals of optial pulse were detected experimentally at different analyzer angles. Finally, after comparing statistical average of leading edge, trailing edge, width, peakvalue, shape and area of optical pulse′s backscatter signal at different analyzer angles, the influence of analyze angle on the backscatter characteristic of optical pulse was analyzed. The result shows that, with the increase of analyzer angle, the backsctter singal′s width becomes narrow, the shape becomes gentle, the peakvalue and area are decreased. The leading edge and trailing edge move backward and the moving distance of leading edge is much larger than that of trailing edge. And the backscatter signal from nearby water area is restrained more effectively by the polarization detection system.
韩彪, 刘继芳, 周少杰, 孙艳玲, 马琳. 检偏角对水中光脉冲后向散射特性的影响[J]. 光子学报, 2011, 40(1): 73. HAN Biao, LIU Ji-fang, ZHOU Shao-jie, SUN Yan-ling, MA Lin. Influence of Analyzer Angle on Backscatter Characteristic of Optical Pulse in Water[J]. ACTA PHOTONICA SINICA, 2011, 40(1): 73.