S-band pulse generation by polarization additive-pulse mode-locking in an erbium-doped all-fiber ring laser

An all-fiber S-band mode-locked Er-doped fiber ring laser operated at 1503 nm is experimentally demonstrated by utilizing the polarization additive-pulse mode-locking (P-APM) mechanism. To the best of our knowledge, it is the first P-APM mode-locked fiber laser operating in the S-band. The gain medium is an S-band Er-doped fiber amplifier (EDFA) composed of two Er-doped fiber stages with the technique of depressed-cladding to cut off the fundamental mode. Stable single-pulse operation is achieved within the available pump power range. Besides, characterization of the S-band EDFA module, such as the wavelength dependences of the gain and noise figure, the slope efficiency, as well as the dependence of the pump power on the gain for different input powers is performed. In addition, analysis of the proposed S-band mode-locked fiber laser, such as the pump power dependence of the pulse-width and optical bandwidth, and pulse-width compression is also provided. (letter)