High-Pulse-Repetition-Rate Eye-Safe Raman Laser with Acousto-Optic Q-Switched Device

The acousto-optic Q-switch is exploited to develop a high-repetition-rate eye-safe Raman laser at 1526 nm. The Nd:YVO₄ and KGW crystals are employed as the fundamental laser and Stokes Raman gain materials, respectively. The influence of the gate-open time on the performance is systematically explored for the repetition rate between 80 and 150 kHz. The separate configuration is used to construct the resonant cavities for the fundamental and Stokes waves to achieve a pulse width that is as short as possible. Under the optimal alignment, the average output power can exceed 5.0 W at a pump power of 30 W for a repetition rate within 100-150 kHz with a gate-open time of 0.5 μs. In addition, the output peak power can be greater than 10 kW for a pulse repetition rate between 80 and 120 kHz. The optical-to-optical conversion efficiency is up to 16.7%, which is better than that obtained by the Nd:YVO₄/YVO₄ system.