Phase-noise suppression for the optical-heterodyne-generated microwave based on the amplitude-to-phase conversion

Authors：Zhang, Zhitao; Zhao, Qilai; Fang, Siyuan; Tan, Tianyi; Yang, Changsheng^*; Lin, Wei; Zhou, Kaijun; Feng, Zhouming; Yang, Zhongmin; Xu, Shanhui

Source：Applied Physics Express, 2021, 14(7): 072003.

DOI：10.35848/1882-0786/ac09be

• photonic microwave
• phase noise
• fiber laser

By reducing the noise component induced by the amplitude-to-phase conversion, a broadband phase-noise suppression of a 20.5 GHz photonic microwave, generated from an optical heterodyne of a dual-wavelength single-frequency fiber laser (DW-SFFL) is experimentally demonstrated. This is done by suppressing the intensity noise of the DW-SFFL through optoelectronic feedback, the microwave shows phase-noise suppression around the frequency range 100 Hz to 100 kHz. The phase-noise suppression of 6.1 dB at 1 kHz offset frequency and a linewidth of 2.15 kHz are obtained from this microwave system. The successful improvement indicates the feasibility of our strategy in obtaining a low phase-noise microwave.