基于光纤的量子椭圆偏振光测量装置

Fiber based Scheme for Quantum Ellipsometry

利用基于光纤的便携式偏振纠缠光子对源作为检测光源,搭建了使用单模光纤进行耦合的量子椭圆偏振光测量装置。实验测量了氧化层厚度为100nm的氧化膜硅片样品,通过将偏振纠缠光子对中的一路经由氧化膜硅片样品进行反射,然后借助双光子符合计数方法测量反射后的量子态,得到了样品的椭圆偏振参数。当入射到样品上的光子波长为1 558.17nm,入射角为30°时,通过三次实验所得的椭圆偏振参数(ψ,Δ)的平均值分别为40.23°和173.10°,标准差分别为0.046°和0.403°,测量结果的相对标准偏差小于1%,同时该结果与仿真模拟值相符。

Using a fiber-based compact source of entangled photon pairs,we build a single-mode-fibercoupled scheme for quantum ellipsometry,and measure the ellipsometric parameters for a 100-nm-thick silica film on silicon substrate.The signal photons of the photon pairs are reflected by the sample under test.By performing the two-photon coincidence counting measurement for the entangled states after the reflection,we obtain the ellipsometric parameters of the sample.When the wavelength and incident angle of the photons sent to the sample are 1558.17 nm and 30°,the measured ellipsometric parameters(ψ,Δ)are 40.23° and 173.10°,with standard deviations 0.046° and 0.403°,respectively.The relative standard deviation of the meausred results is less than 1%,and the results agree well with theoretical predictions.