Generation of 12th order harmonic mode-locking in a Nd-doped single-mode all-fiber laser operating at 0.9 μm

Based on the Nd-doped single-mode fiber as the gain medium, an all-fiber 12th harmonic mode-locked(HML) laser operating at the 0.9 μm waveband was obtained for the first time, to the best of our knowledge. A mandrel with a diameter of 10 mm was employed to introduce bending losses to suppress mode competition at 1.06 μm, which resulted in a suppression ratio of up to 54 dB. The 1st–12th order HML pulses with the tunable repetition rate of 494.62 kHz–5.94 MHz were obtained in the mode-locked lase...