All-fiber actively mode-locked Tm-doped pulse laser at 2 μm

An all-fiber Tm-doped pulse laser with active mode-locking is demonstrated, the center wavelength is 1.95 m. The phase in the laser cavity was modulated by an electronic optical phase modulator, and an actively mode-locked pulse output with a repetition rate of 11.884 MHz was obtained, the pulse duration was 816 ps. Relaxation oscillation modulated stable pulse train with a repetition rate of 4-18 kHz was realized by adjusting the pump power, the frequency and amplitude of modulating signal. All the energy fluctuations of the stable pulse trains were less than 7%.