All-optical noise reduction of fiber laser via intracavity SOA structure

National Natural Science Foundation of China (NSFC) [61475165, 61535014, 61377062]; Youth Innovation Promotion Association of the Chinese Academy of SciencesWe have designed a unique intracavity semiconductor optical amplifier (SOA) structure to suppress the relative intensity noise (RIN) for a fiber DFB laser. By exploiting the gain saturation effect of the SOA, a maximum noise suppression of 30 dB around the relaxation oscillation frequency is achieved, and the whole resonance relaxation oscillation peak completely disappears. Moreover, via a specially designed intracavity SOA structure, the optical intensity inside the SOA will be in a balanced state via the oscillation in the laser cavity, and the frequency noise of the laser will not be degraded with the SOA. (C) 2016 Optical Society of Americ