Passively Q-Switched Ho :YAG Ceramic Laser with a GaAs Saturable Absorber

Abstract

We report on a passively Q-switched 2 μm Ho :YAG ceramic laser, using pure GaAs as a saturable absorber. At an absorbed pump power of 1.28 W, the highest pulse repetition rate, shortest pulse width, largest single pulse energy, and highest peak power are measured to be 295 kHz, 83 ns, 1.49 μJ and 17.95 W, respectively. To the best of our knowledge, this is the first 2 μm passively Q-switched laser with a pure GaAs absorber, the three-photon absorption is believed to play an important role in the saturable absorption process.