Actively Q-switch operation of diode-pumped Er,Yb:YAl3(BO3)4 laser at 1.5-1.6 μm

We report, for the first time to our knowledge, an acousto-optic Q-switched Er,Yb:YAl 3 (BO 3 ) 4 crystal laser operating in the 1.5 – 1.6 μm spectral region. The output characteristics of the lasers with different duty cycles, pulse repetition frequencies (PRF) and output couplers were investigated. The maximum single pulse energy of 91 μJ with the pulse width of 135 ns and the PRF of 5 kHz was achieved when the transmission of output coupler T = 1% and the duty cycle was optimized at 2.5%. The shortest pulse width of 90 ns was obtained at the PRF of 3 kHz for the transmission of output coupler T = 1.5%. The blue shift of laser emission and shortening of pulse width with reduction of PRF and increment of the pump power were observed.