LiNbO₃ Pockels cell for Q-switch of Er:YAG laser

Abstract

Specially designed LiNbO 3 electrooptic shutter was used for Q-switching of Er:YAG laser system. Brewster angles was employed at the Pockels cell LiNbO 3 crystal faces to avoid the insertion of a polarizer into the resonator. By help of the theoretical analysis based on Jones calculus, the dependency of Pockels cell radiation transmission on applied voltage was found. Theoretically and experimentally was proved, that for 25 mm long LiNbO 3 crystal the voltage of 1.5 kV is sufficient to avoid the laser oscillation. With this Pockels cell a stable running Q-switched Er:YAG laser system was realized. The generated giant pulse length and energy was 70 ns and 30 mJ, respectively.