An effective and universal intensity noise suppression technique for single-frequency fiber lasers at 1.5 μm

Authors：Zhou, Kaijun; Zhao, Qilai; Feng, Zhouming; Yang, Changsheng; Xu, Shanhui^*

Source：LASER PHYSICS, 2021, 31(7): 075101.

DOI：10.1088/1555-6611/abf5d2

• fiber laser
• noise suppression
• single-frequency

We report on an effective and universal technique to fulfill intensity noise suppression for single-frequency fiber lasers (SFFLs) at 1.5 mu m. Utilizing a gain-saturated semiconductor optical amplifier and the effective filtering of amplified spontaneous emission, the resultant relative intensity noises of three diverse SFFLs are maintained at -155 dB Hz(-1); which is only <0.9 dB from the shot noise limit in the frequency range from 100 kHz to 50 MHz. Refering to the three paradigmatic experimental results, this technology, as a promising external solution of noise suppression, can be modularized to promote the application of SFFLs.