Quantum-enhanced optical precision measurement assisted by low-frequency squeezed vacuum states  

作　　者：康国辉 冯晋霞 程琳 李渊骥 张宽收 Guohui Kang;Jinxia Feng;Lin Cheng;Yuanji Li;Kuanshou Zhang(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,China [2]Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China

出　　处：《Chinese Physics B》2023年第10期438-442,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.62175135);the Fundamental Research Program of Shanxi Province(Grant No.202103021224025)。

摘　　要：Stable low-frequency squeezed vacuum states at a wavelength of 1550 nm were generated.By controlling the squeezing angle of the squeezed vacuum states,two types of low-frequency quadrature-phase squeezed vacuum states and quadrature-amplitude squeezed vacuum states were obtained using one setup respectively.A quantum-enhanced fiber Mach–Zehnder interferometer(FMZI)was demonstrated for low-frequency phase measurement using the generated quadrature-phase squeezed vacuum states that were injected.When phase modulation was measured with the quantumenhanced FMZI,there were above 3 dB quantum improvements beyond the shot-noise limit(SNL)from 40 kHz to 200 kHz,and 2.3 dB quantum improvement beyond the SNL at 20 kHz was obtained.The generated quadrature-amplitude squeezed vacuum state was applied to perform low-frequency amplitude modulation measurement for sensitivity beyond the SNL based on optical fiber construction.There were about 2 dB quantum improvements beyond the SNL from 60 kHz to 200 kHz.The current scheme proves that quantum-enhanced fiber-based sensors are feasible and have potential applications in high-precision measurements based on fiber,particularly in the low-frequency range.

关 键 词：squeezed vacuum states fiber Mach–Zehnder interferometer optical precision measurement 

分 类 号：O431.2[机械工程—光学工程]