Fiber Noise Suppression System with Additional Linewidth of mHz-Level for Ultra-Stable Lasers

We demonstrate a fiber noise suppression system used in the ultra-stable laser aiming to compress the laser linewidth in remote place. This system is realized by using an active feedback control technique and composed of a Michelson interferometer and phase locked loop. This paper reported the fiber noise suppression system can reduce the extra linewidth introduced by the 1 m long fiber from the initial 250 Hz to 1.8 mHz.