▎ 摘　　要

An ultra-wide wavelength tuning range, which covers three different band regions consisting of the S-, C-, and L-bands, is proposed and demonstrated for a graphene-based Q-switched erbium-doped fiber laser using a tunable bandpass filter as the wavelength tuning and filtering mechanism. A 3m length of erbium-doped fiber is used as the gain medium in a ring laser cavity configuration, with absorption coefficients of between 11 and 13 dBm(-1) at 980nm and about 18dBm(-1) at 1550nm. The tuning range of the Q-switching pulses covers a wide wavelength range of 58nm, which spans from 1512.5nm to 1570.5nm. In addition, the lasing and Q-switching thresholds are considerably low, with respective values of approximate to 11.0mW and approximate to 18.4mW. A repetition rate of 55.3kHz is obtained at the maximum pump power of 100.4mW, together with pulse width and pulse energy of 1.6s and 25.8nJ, respectively.