Yang Chen, Zhou Zhi-Yuan, Wang Liu-Long, Li Yan, Liu Shi-Kai, Ge Zheng, Zhang Xiao-Chun, Tang Qing, Guo Guang-Can, Shi Bao-Sen
Opt Express. 2021 Sep 27;29(20):32006-32019. doi: 10.1364/OE.437624.
Quantum nonlinear interferometers (QNIs) can measure the infrared physical quantities of a sample by detecting visible photons. A QNI with Michelson geometry based on the spontaneous parametric down-conversion in a second-order nonlinear crystal is studied systematically. A simplified theoretical model of the QNI is presented. The interference visibility, coherence length, equal-inclination interference, and equal-thickness interference for the QNI are demonstrated theoretically and experimentally. As an application example of the QNI, the refractive index and the angle between two surfaces of a BBO crystal are measured using equal-inclination interference and equal-thickness interference.
量子非线性干涉仪（QNIs）可以通过检测可见光子来测量样品的红外物理量。系统地研究了一种基于二阶非线性晶体中的自发参量下转换的迈克尔逊几何结构的量子非线性干涉仪。提出了该量子非线性干涉仪的简化理论模型。从理论和实验上论证了该量子非线性干涉仪的干涉可见度、相干长度、等倾干涉和等厚干涉。作为该量子非线性干涉仪的一个应用实例，利用等倾干涉和等厚干涉测量了一块BBO晶体的折射率和两个表面之间的夹角。
