Optics Express

Stabilization improvement of the squeezed optical fields using a high signal-to-noise ratio bootstrap photodetector

Xiaoli Wang, Liang Wu, Shaocong Liang, Jialin Cheng, Yanhong Liu, Yaoyao Zhou, Jiliang Qin, Zhihui Yan, Xiaojun Jia

Published Dec 5, 2022• 5 citations

Abstract

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.

DOI: 10.1364/oe.475941

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