title: Broad-bandwidth near-shot-noise-limited intensity noise suppression of a single-frequency fiber laser.
abstract: A significant broad-bandwidth near-shot-noise-limited intensity noise suppression of a single-frequency fiber laser is demonstrated based on a semiconductor optical amplifier (SOA) with optoelectronic feedback. By exploiting the gain saturation effect of the SOA and the intensity feedback loop, a maximum noise suppression of over 50 dB around the relaxation oscillation frequencies and a suppression bandwidth of up to 50 MHz are obtained. The relative intensity noise of -150  dB/Hz in the frequency range from 0.8 kHz to 50 MHz is achieved, which approaches the shot-noise limit. The obtained optical signal-to-noise ratio is more than 70 dB. This near-shot-noise-limited laser source shows important implications for the advanced fields of high-precision frequency stabilization, quantum key distribution, and gravitational wave detection.
authors.forename: Qilai
authors.initials: Q
authors.lastname: Zhao
authors.forename: Shanhui
authors.initials: S
authors.lastname: Xu
authors.forename: Kaijun
authors.initials: K
authors.lastname: Zhou
authors.forename: Changsheng
authors.initials: C
authors.lastname: Yang
authors.forename: Can
authors.initials: C
authors.lastname: Li
authors.forename: Zhouming
authors.initials: Z
authors.lastname: Feng
authors.forename: Mingying
authors.initials: M
authors.lastname: Peng
authors.forename: Huaqiu
authors.initials: H
authors.lastname: Deng
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Yang