Using dual ring structure with different coupling ratio for S-band erbium-based fiber laser

An S-band erbium-doped fiber (EDF) ring laser, using a dual coupler ring structure (DCRS) with different coupling ratio injection, is proposed and demonstrated experimentally. The proposed fiber ring laser does not use any fiber Bragg gratings or etalon filters (passive or active filter) into the loop cavity to lase a single wavelength. This proposed fiber laser has an optical signal to noise ratio (OSNR) of > 38.2 dB and output power of - 3.8 dBm at 1506.28 nm, while the coupling ratio in a ring cavity is 10%. Moreover, the performances of output power and wavelength stabilities have also been studied and discussed