▎ 摘　　要

We report graphene mode-locked or Q-switched Tm/Ho-codoped fiber laser pumped by a 1212-nm phosphorus-doped fiber Raman laser. First, comparison experiments were performed for a continuous-wave 2 mu m Tm/Ho-codoped fiber laser pumped by a 1565-nm laser or a 1212-nm laser, verifying that the 1212-nm pumping is more efficient than the conventional similar to 1560-nm pumping. Then, we further realized 1212-nm highly efficient pumped Tm/ Ho-codoped fiber lasers mode-locked and Q-switched by a graphene saturable absorber, respectively. Using only 30-cm Tm-Ho gain fiber under the 1212-nm pumping, the passive Q-switching at a center wavelength of 1976 nm was efficiently generated with tunable repetition rate between 32.2 and 43.0 kHz and shortest pulse width of 1.41 mu s. Moreover, the passive mode-locking at 1913.7 nm was stably achieved with a fundamental repetition rate of 19.978 MHz and pulse energy of similar to 20 pJ. To the best of our knowledge, it is the first demonstration of 2-mu m pulsed fiber lasers high efficiently pumped by a 1212-nm laser. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)