“…Ultrafast pulse lasers with high pulse repetition rates possess widespread applications, including laser gyroscopes, laser radar systems, multiphoton microscopy, nonlinear bioimaging, and so on, due to their exceptional compactness, rather low cost and excellent pulse output properties. [1][2][3][4][5][6][7][8][9][10][11] Since the end of the last century, theories and experiments on the harmonic mode-locked (HML) fiber lasers have been widely reported. [12][13][14][15][16] The HML pulses can be acquired via the passively mode-locked technique based on nonlinear amplifying loop-mirror, 17 nonlinear polarization rotation, 12,18,19 or real saturable absorbers (SAs).…”