High-power repetition rate- and pulse width-tunable 589 nm versatile laser for adaptive optical systems

Compact high-power yellow laser is a critical part for sodium beacon adaptive optical systems. A narrow-linewidth quasi-continuous-wave (QCW) solid-state 589 nm laser with high-power and high beam quality simultaneously is investigated here, operating in hundreds-microsecond pulse duration with a tunable repetition rate of 4(X) to 1 kHz, which is flexible to allow the telescope to move in observing direction. The laser source is based on employing sum-frequency generation between 1319 and 1064 nm QCW Nd:YAG amplifiers. For a 100 mu s pulse duration and 400 Hz repetition rate, the yellow laser provides a highest output power of 86.1 W with beam quality M-2 = 1.37. The central wavelength can be precisely tuned to sodium-D-2a, line at 589.159 nm with a similar to 440 MHz linewidth. This is the maximum power-reported for all-solid-state sodium guide star laser demonstrated to date. The result represents a key step toward solving the requirement of multi-conjugate adaptive optics for large adaptive optical telescopes. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement