基于液晶光阀调制的赝热光源制备技术研究

Research on the Pseudo-Thermal Light Made by Liquid Crystal Spatial Light Modulation

高质量赝热光源的制备是强度关联成像技术中一个非常重要的内容。采用赝热光作为光源是因为一般的热光源相干时间极短,常用的探测器无法响应,且亮度低。利用激光照射旋转的毛玻璃形成的动态散斑作为赝热光源可以解决上述问题,是目前常用的一种方法。提出一种采用液晶光阀(LC-SLM)对激光束进行控制来获得赝热光场的方法。利用该装置产生的赝热光场不仅可以极大程度地模拟真实热光场的热涨落,且光场涨落服从真实热光场所具有的高斯统计分布,更重要的是该系统没有机械转动,光场的时间和空间相干性可以完全分开对待,产生的散斑场结果可以重复,并研究了应用该方法产生的动态散斑场的各种特性。

How to get a high-quality pseudo-thermal light source is very important to the intensity quantum imaging experiment.The reason of using pseudo-thermal light instead of true thermal light is the coherence time of true thermal light is too short to respond by the common detectors,and its intensity very low.It is a common method to use dynamic speckles produced by the laser transmitting through a rotary ground glass as a pseudo-thermal light source in order to overcome these problems.The paper proposed using a liquid crystal spatial light modulation（LC-SLM） controlling the laser beam to get a pseudo-thermal light source.It can simulate the intensity fluctuation of true thermal light extremely,and it obeys to Gauss statistical distribution property.In addition,it is a non-mechanical system.The temporal and the spatial coherence can be treated separately,so the result is repeatable.The characteristic of the dynamic speckle is also studied.