Chinese Optics Letters, Vol. 17, Issue 7, 072701 (2019)
Detection of 13.8 dB squeezed vacuum states by optimizing the interference efficiency and gain of balanced homodyne detection
Xiaocong Sun1, Yajun Wang1,2, Long Tian1,2, Yaohui Zheng1,2,*, and Kunchi Peng1,2
- 1State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China
- 2Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
Squeezed states belong to the most prominent non-classical resources. They have compelling applications in precise measurement, quantum computation, and detection. Here, we report on the direct measurement of 13.8 dB squeezed vacuum states by improving the interference efficiency and gain of balanced homodyne detection. By employing an auxiliary laser beam, the homodyne visibility is increased to 99.8%. The equivalent loss of the electronic noise is reduced to 0.05% by integrating a junction field-effect transistor (JFET) buffering input and another JFET bootstrap structure in the balanced homodyne detector.