Aluminized Film as Saturable Absorber for Generating Passive Q-Switched Pulses in the Two-Micron Region

A passively Q-switched two-micron fiber laser using an aluminized film as a saturable absorber (SA) is proposed and demonstrated. The SA consists of a solar tint film originally used for ultraviolet light rejection, and placed in a Thulium-doped fiber laser. Q-switching is observed at a pump power of 134.41 mW, with repetition rates increasing steadily from 22.96 to 40.32 kHz at a maximum pump power of 205.08 mW. The pulse width has an average value of 5.5 μs, while a maximum pulse energy and peak power of 173.52 nJ and 33.37 mW, respectively, are obtained. This is the first time, to the author's knowledge, aluminized solar tint film has been demonstrated as an SA for pulsed laser generation in the two-micron region.