title: 20 W of continuous-wave sodium D2 resonance radiation from sum-frequency generation with injection-locked lasers.
abstract: A 20-W all-solid-state continuous-wave single-frequency source tuned to the sodium D2a line at 589.159 nm has been developed for adaptive optical systems. This source is based on sum-frequency mixing two injection-locked Nd:YAG lasers in lithium triborate in a doubly resonant external cavity. Injection locking the Nd:YAG lasers not only ensures single-frequency operation but also allows the use of a single rf local oscillator for Pound-Drever-Hall locking both the injection-slave and the sum-frequency cavities. We observe power-conversion efficiencies in excess of 55% and a linearly polarized diffraction-limited output tunable across the sodium D2 line (589.156 to 589.160 nm) with no change in output power and with high amplitude and pointing stability.
authors.affiliation: Directed Energy Directorate, Air Force Research Laboratory, Kirtland Air Force Base, New Mexico 87117, USA.
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Bienfang
authors.forename: Craig A
authors.initials: CA
authors.lastname: Denman
authors.forename: Brent W
authors.initials: BW
authors.lastname: Grime
authors.forename: Paul D
authors.initials: PD
authors.lastname: Hillman
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Moore
authors.forename: John M
authors.initials: JM
authors.lastname: Telle