激光技术的发展已将激光脉冲的宽度压缩到微微秒量级。如此短的激光脉冲将使许多物理、化学等快速过程的研究成为可能,然而对测量技术也带来了较大的困难。对于红外激光脉冲的检测,常用光子牵引探测器、热电探测器及碲镉汞探测器等,其响应时间一般大于1ns。有的则检测灵敏度低或需低温条件等,这就使这类检测技术受到限制。但是在可见光或近红外波段却有一些光电检测技术,尤其是适宜于测量短脉冲的高速照相、双光子荧光技术及快速条纹照相术等,在灵敏度或时间分辨率等方面都大有提高,可是这类检测系统却不能直接用于红外激光脉冲的测量。 1964年,Mayer等首先提出了用强功率偏振光脉冲取代传统克尔开关中的电脉冲而产生双折射效应。Duguay等在这个原理上建立了测量脉冲激光的行波光学克尔开关。其设想是用一强的偏振光脉冲(“开关光束”)在克尔介质内感生一个短暂的双折射,从而对另一偏振方向与之成45°的“探针光束”产生调制作用,也就是使其偏振面产生旋转而得以通过原置于正交位置的检偏器,最后所获得的透射光讯号就反映了原“开关光束”的变化情况。在[3][4]中将上述思想用于10.6μ红光激光脉冲的调制变换,然而由光 Advances in laser technology have compressed the width of laser pulses to the order of picoseconds. Such a short pulse of laser light will make many of the physical, chemical and other rapid process studies possible, however, and measurement techniques have also brought greater difficulties. For the detection of infrared laser pulse, commonly used photon traction detectors, pyroelectric detectors and mercury cadmium telluride detectors, the response time is generally greater than 1ns. Some are low sensitivity or low temperature conditions, which makes this type of detection technology is limited. However, there are some photodetection technologies in the visible or near-infrared range, especially the high-speed photography suitable for short bursts, two-photon fluorescence and fast streak photography, etc., which are greatly improved in sensitivity or time resolution, etc. However, Such detection systems can not be directly used for infrared laser pulse measurement. In 1964 Mayer and others first proposed the use of strong power polarized pulses instead of the traditional Kerr switch in the electrical pulse birefringence effect. Based on this principle, Duguay et al. Established a traveling-wave optics Kerr switch for measuring pulsed lasers. The idea is to induce a brief birefringence in the Kerr medium with a strong polarized pulse of light (“switching beam”), modulating the “probe beam” at 45 ° to the other polarization, That is, the polarization plane is rotated to pass through the original analyzer placed in the orthogonal position, the final transmitted light signal reflects the original “switch beam” changes. The above notion was used in [3] [4] for the modulation conversion of a 10.6μ red laser pulse, however,