Experimental study of dual-wavelength quasi-mode-locked Er-fiber laser with a strict polarization-controlled

We report dual-wavelength mode-locked operation of a passively mode-locked Er-doped fiber laser (EDFL) including two sections of a fiber with equal length, one right hand twisted and another left hand twisted, and a double-pass amplifier with Faraday Mirror (FM). The configuration allows cancellation of the influence of both linear and circular birefringence and strict control of the polarization of pulses in the cavity. Depending on the polarization azimuth we observed synchronous dual-wavelength, 1532 nm and 1560 nm, noise-like pulses (NLP), and desynchronized soliton emission.