Versatile Raman fiber laser for sodium laser guide star

摘要

Robust high-power narrow-linewidth lasers at 589 nm are required for sodium laser guide star adaptive optics in astronomy. A high-power 589 nm laser based on Raman fiber amplifier is reported here, which works in both continuous-wave and pulsed formats. In the continuous-wave case, the laser produces more than 50 W output. In the pulsed case, the same laser produces square-shaped pulses with tunable repetition rate (500Hz to 10kHz) and duration (1ms to 30μs). The peak power is as high as 84 W and remains constant during the tuning. The laser also emits an adjustable sideband at 1.71 GHz away from the main laser frequency for better sodium excitation. The versatility of the laser offers much flexibility in laser guide star application.