Realization and characterization of single-frequency tunable 637.2 nm   high-power laser
  We report the generation of narrow-linewidth 637.2 nm laser by single-pass sum-frequency generation (SFG) of two infrared lasers at 1560.5 nm and 1076.9 nm in PPMgO:LN crystal. Over 8.75 W of single-frequency continuously tunable 637.2 nm laser is realized, and corresponding conversion efficiency is 38%. We study the behavior of crystals with different poling periods. The detailed experiments show that the output red lasers have very good power stability and beam quality. This high-performance 637.2 nm laser is significant for the realization of high power ultra-violet (UV) 318.6 nm laser via cavity-enhanced frequency doubling. Narrow-linewidth 318.6 nm laser is important for Rydberg excitation of cesium atoms via single-photon transition. 
Jieying Wang, Jiandong Bai, Jun He and Junmin Wang
physics.optics physics.atom-ph