Anti-misalignment Er:YAG single-longitudinal-mode laser based on acousto-optic Q-switching technology

We have demonstrated a single-longitudinal-mode (SLM) Er:YAG laser operating at a central wavelength of 1645.10 nm, which is constructed with an acousto-optic Q-switch (AOQS) integrated into a double corner-cube-retroreflector (CCR) ring cavity. By tilting the AOQS (with radio frequency (RF) power applied) to deviate slightly from the Bragg angle, a maximum continuous-wave (CW) SLM output power of 0.953 W is achieved, corresponding to a slope efficiency of 6.32%. Furthermore, a single-frequency pulsed Er:YAG laser with a repetition rate of 1 kHz is realized by periodically driving the AOQS with a RF signal generated from the signal generator. At this repetition rate, the laser delivers a single-frequency pulse with an energy of 0.258mJ and a pulse width of 824 ns. Additionally, the beam quality factors M ² of the pulsed laser are measured to be 1.08 and 1.19 along the horizontal ( x ) and vertical ( y ) directions, respectively.