Stable noise-like pulse generation from a NALM-based all-PM Tm-doped fiber laser

An all-polarization maintaining (PM) noise-like pulse (NLP) generation from a Tm-doped fiber oscillator based on nonlinear amplifying loop mirror (NALM) that incorporated with a phase shifter and a chirped fiber Bragg grating (CFBG) is experimentally demonstrated. The 3 dB bandwidth of the output spectrum is 25 nm at the central wavelength of 1950 nm, and the maximum output average power is 13.6 mW with the repetition rate of 3.25 MHz. The noise performances of the NLP are for the first time systematically examined, and it shows an improving tendency with the increasing of the output power. At an integration frequency range from 1 kHz to 1 MHz, the minimum estimated timing jitter and the rms RIN is 139 ps and 0.58%, respectively. In addition, the long-term stable operation of the laser is verified through monitoring the output spectrum and average power.