基于光学参量放大器的量子干涉仪的分析

Analysis of Quantum Interferometer Based on Optical Parametric Amplifier

高精度光学干涉仪是实现精密测量的重要工具之一,干涉仪的最终灵敏度受限于真空起伏决定的标准量子极限(SQL)。利用量子资源可以实现突破SQL的相位测量。在基于光学参量放大器(OPA)的量子干涉仪中,将干涉仪两臂中OPA产生的相位压缩态直接作为相敏量子态,通过同时降低散粒噪声和放大相敏场强可以使其灵敏度无条件地突破SQL。然而,量子态对损耗是非常敏感的。通过分析量子干涉仪的各种损耗对其灵敏度的影响,得出了量子干涉仪灵敏度与各种损耗的依赖关系。同时,通过分析灵敏度与分析频率等其他物理参量的关系,得出了进一步优化系统灵敏度、带宽等性能的实验参数。

A high-precision optical interferometer is one of the basic tools for precision measurement,and the ultimate sensitivity of the interferometer is limited by the standard quantum limit(SQL)determined by vacuum fluctuations.By making use of quantum resources,the phase measurement beyond SQL can be realized.In a quantum interferometer based on optical parametric amplifier(OPA),squeezed states produced by OPAs in the two arms are directly used as phase-sensitive quantum states.In addition,the sensitivity of the quantum interferometer can unconditionally surpass SQL by the simultaneous shot noise reduction and amplification of phase-sensitive field intensity.However,quantum states are very sensitive to losses.By analyzing the influence of all kinds of losses on sensitivity,the relationship between sensitivity of the quantum interferometer and losses is obtained.Meanwhile,through analyzing the relationship between sensitivity and other physical parameters such as analysis frequency,the experimental parameters for further optimization of performance including system sensitivity and bandwidth are obtained.