关键词: 量子光学/
音频段压缩态光场/
简并光学参量振荡器/
1.34 μm光通信波段
English Abstract
Generation of audio-band frequency squeezed light at 1.34 μm
Feng Jin-Xia1,2,Du Jing-Shi1,
Jin Xiao-Li1,2,
Li Yuan-Ji1,2,
Zhang Kuan-Shou1,2
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
Fund Project:Project supported by the National Key Research and Development Plan of China (Grant No. 2016YFA0301401) and Sponsored by the Fund for Shanxi "1331Project" Key Subjects Construction (Grant No. 1331KSC).Received Date:06 February 2018
Accepted Date:18 April 2018
Published Online:05 September 2018
Abstract:Continuous variable (CV) audio-band frequency squeezed states at the fiber telecommunication wavelength is an important quantum resource for the practical applications based on optical fiber. As is well known, the optical power attenuation and phase diffusion effect of light at 1.3 μm in standard telecommunication fibres are low and small, respectively. The audio-band frequency squeezed light at 1.34 μm can be utilized to realize quantum precision measurement, such as quantum-enhanced sensing in the low-frequency range, laser interferometer for gravitational wave detection. In this paper, CV audio-band frequency vacuum squeezed states at 1.3 μm are experimentally generated by using a type-I degenerate optical parametric oscillator (DOPO) below the threshold. A home-made continuous-wave single-frequency dual-wavelength (671 nm and 1.34 μm) Nd:YVO4/LBO laser is used as a pump source for DOPO based on a type-I quasi-phase-matched periodically poled KTiOPO4 (PPKTP) crystal. Mode cleaners with a finesse of 400 and linewidth of 0.75 MHz are used to filter the noise of lasers at 671 nm and 1.34 μm, respectively. The intensity noises of the two lasers reach a shot noise level for analysis frequencies higher than 1.0 MHz and their phase noises reach shot noise level for analysis frequencies higher than 1.3 MHz, respectively. The low noise single-frequency 671 nm laser is utilized as a pump of the DOPO. The threshold power of the DOPO is 450 mW. In order to detect the audio-band frequency vacuum squeezed states, the power of local oscillator of a homodyne detector system is optimized to 60 μupW. Furthermore, the effect of common mode rejection ratio (CMRR) of detectors is discussed in detecting the audio-band frequency vacuum squeezed states. Improvement of CMRR of detectors is a good way to detect the audio-band frequency vacuum squeezed states effectively. When the phase matching temperature of PPKTP crystal is controlled at 53℃ by using a home-made temperature controller and the pump power is 95 mW, the vacuum squeezed states are generated at analysis frequency ranging from 8-100 kHz. A maximum measured squeeze of 5.0 dB is obtained at analysis frequency of 36 kHz. A 3.0 dB squeezed light is obtained at an audio-band frequency of 8 kHz.
Keywords: quantum optics/
audio-band frequencies squeezed light/
degenerate optical parametric oscillator/
fiber telecommunication wavelength of 1.34 μm
