Investigation on the effect of output mirror transmission in WS-based red-light passively Q-switched Pr:ZBLAN all-fiber lasers.

We report the experimental investigation of visible passively Q-switched Pr-doped all-fiber lasers with tungsten disulfide (WS) saturable absorber, where red-light short-pulse generations from different output mirror transmissions are systemically characterized. The proposed simple and compact all-fiber linear cavity was constructed by a fiber-pigtail-based blue laser-diode pump, a Pr-doped fluorozirconate glass active fiber, and the fiber end-facet mirrors. Integrating a free-standing layered WS film into the laser cavity initiated the Q-switching operation. Stable microsecond-duration output pulses with kilohertz repetition rates are achieved, corresponding to a few mW/nJ average output power and single-pulse energy. The comparisons on red-light Q-switched output parameters for output transmissions of both ∼40% and ∼80% are performed. This work could provide a useful guideline to manipulate the output performance of visible pulsed all-fiber lasers for various practical applications.