摘要

The stable soliton pulse laser with tunable harmonic orders has been obtained using a graphene-based passively mode-locked erbium-doped fiber (EDF) ring for the first time. By adjusting the polarization controller (PC) to change the cavity loss, the mode-locked soliton laser can be tunable from the fundamental order to the fourth harmonic order. The fundamental pulse repetition rate is 3.873 MHz, the central wavelength of laser is 1557.6 nm, the linewidth is 4.5 nm with obvious soliton edge band, and the signal to noise ratio (SNR) is about 45 dB. The pulse repetition rates of the second, third and fourth harmonics are 7.745 MHz, 11.618 MHz and 15.491 Mhz, respectively. The experimental results in this paper can be explained with the multi-soliton formation in mode-locked laser working in abnormal dispersion region.