Wang Xiaoli, Wu Liang, Liang Shaocong, Cheng Jialin, Liu Yanhong, Zhou Yaoyao, Qin Jiliang, Yan Zhihui, Jia Xiaojun
Opt Express. 2022 Dec 19;30(26):47826-47835. doi: 10.1364/OE.475941.
High-precision cavity locking is crucial for squeezing optical fields. Here, a bootstrapped low-noise photodetector is utilized in the generation process of the squeezed state of light. This process is based on a combination of a modified trans-impedance amplifier (TIA) circuit and a two-stage bootstrap amplifier circuit. This not only achieves high-precision and long-term stable locking of the optical cavity, but it also improves the degree to which the light field is squeezed. The experiment results show that the detector has a high signal-to-noise ratio (SNR) of 26.7 dB at the analysis frequency of 3 MHz when measuring the shot noise with an injection optical power of 800 µW, and the equivalent optical power noise level is lower than 2.4 pW/Hz in the frequency range of 1-30 MHz. Moreover, the squeezing degree of the quadrature amplitude squeezed state light field can be improved by more than 34.9% when the detector is used for optical cavity locking. The photodetector is useful in continuous variable (CV) quantum information research.
高精度腔锁定对于压缩光场至关重要。在此，在光压缩态的产生过程中使用了自举式低噪声光电探测器。该过程基于改进的跨阻放大器（TIA）电路和两级自举放大器电路的组合。这不仅实现了光腔的高精度和长期稳定锁定，还提高了光场的压缩程度。实验结果表明，在注入光功率为800 μW测量散粒噪声时，该探测器在3 MHz分析频率下具有26.7 dB的高信噪比（SNR），并且在1 - 30 MHz频率范围内等效光功率噪声水平低于2.4 pW/Hz。此外，当该探测器用于光腔锁定时，正交振幅压缩态光场的压缩程度可提高超过34.9%。该光电探测器在连续变量（CV）量子信息研究中很有用。
