Chen Chaoyong, Shi Shaoping, Zheng Yaohui
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China and Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China.
Rev Sci Instrum. 2017 Oct;88(10):103101. doi: 10.1063/1.5004418.
In an actual setup of squeezed state generation, the stability of a squeezing factor is mainly limited by the performance of the servo-control system, which is mainly influenced by the shot noise and gain of a photodetector. We present a unique transformer-coupled LC resonant amplifier as a photodetector circuit to reduce the electronic noise and increase the gain of the photodetector. As a result, we obtain a low-noise, high gain photodetector with the gain of more than 1.8×10 V/A, and the input current noise of less than 4.7 pA/Hz. By adjusting the parameters of the transformer, the quality factor Q of the resonant circuit is close to 100 in the frequency range of more than 100 MHz, which meets the requirement for weak power detection in the application of squeezed state generation.
在实际的压缩态产生装置中，压缩因子的稳定性主要受伺服控制系统性能的限制，而伺服控制系统主要受光电探测器的散粒噪声和增益的影响。我们提出一种独特的变压器耦合LC谐振放大器作为光电探测器电路，以降低电子噪声并提高光电探测器的增益。结果，我们获得了一种低噪声、高增益的光电探测器，其增益大于1.8×10 V/A，输入电流噪声小于4.7 pA/Hz。通过调整变压器的参数，谐振电路的品质因数Q在超过100 MHz的频率范围内接近100，这满足了压缩态产生应用中微弱功率检测的要求。
