Automatic amplitude control for phasemeter of spaceborne laser interferometry
Hao-Jie Li,
Hong-Xing Qi,
Ming-Zhong Pan,
Xin-Dong Liang,
Jian-Jun Jia,
Guo-Dong Liu,
Jian-Yu Wang
Affiliations
Hao-Jie Li
Key Laboratory of Space Active Opto-Electronic Technology and Systems, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Hong-Xing Qi
Taiji Laboratory for Gravitational Wave Universe, School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, Hangzhou 310012, China
Ming-Zhong Pan
Taiji Laboratory for Gravitational Wave Universe, School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, Hangzhou 310012, China
Xin-Dong Liang
Taiji Laboratory for Gravitational Wave Universe, School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, Hangzhou 310012, China
Jian-Jun Jia
Key Laboratory of Space Active Opto-Electronic Technology and Systems, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Guo-Dong Liu
Taiji Laboratory for Gravitational Wave Universe, School of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, Hangzhou 310012, China
Jian-Yu Wang
Key Laboratory of Space Active Opto-Electronic Technology and Systems, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Laser interferometry of the space gravitational wave antenna needs to demodulate the gravitational wave signal by a phasemeter with high phase readout precision. A phasemeter in digital phase locking loop structure was proved to be sensitive to the amplitude fluctuation of the input signal experimentally in previous studies. In this work, we have carried out theoretical analysis on the influence of amplitude fluctuation on phase readout precision. The results show that amplitude noise belongs to multiplicative noise, which cannot be eliminated by differential measurement. We used the automatic gain control (AGC) circuit to suppress the fluctuation of amplitude. Contrast experiments were performed to verify that the AGC circuit could promote the performance of the phasemeter system for gravitational wave detection.
