Using ring-filter and saturable-absorber-based filter for stable erbium fiber laser

Abstract

A stable single-frequency dual-coupler ring (DCR) laser is proposed that operates in a single mode for more than an hour by an incorporating unpumped erbium-doped fiber (EDF) as a saturable-absorber filter and optimizing the length of the EDF used as gain medium. The proposed fiber laser doesn't use any fiber Bragg gratings or etalon filters into intracavity to lase a single-frequency. This laser has an optical signal to noise ratio (OSNR) of > 60 dB at 1562.9 nm. In addition, the stabilities of the output power and wavelength have also been studied.