Development of 2 μm acousto-optic Q switch

This article introduces an acousto-optic Q switch used for adjusting Q in a 2 μm solid-state laser. "Mismatch rate" is firstly used to represent the degree to which the impedance does not match and the LC matching network is used to decreases the mismatch rate of impedance from 0.82 to 0 and doubles the diffraction loss. The article presents the design of improving heat dissipation speed and thus improving reliability of the product by decreasing the width of acousto-optic medium. The acousto-optic Q switch adopts a quartz crystal as the acousto-optic interaction medium, the length of light direction is 45 mm, clear aperture is 3 mm, 2 μm linear polarized diffraction loss is up to 88% when the driving power is 80 W. The device is used for Ho:YA laser, in repetition frequency 10 kHz, obtain the single pulse energy of 1.6 mJ, 20 ns pulse width.