title: High-power Er:YAG laser with quasi-top-hat output beam.
abstract: A simple method for simultaneously exciting the fundamental (TEM00) transverse mode and first order Laguerre-Gaussian (LG01) donut mode in an end-pumped solid-state laser to yield a quasi-top-hat output beam is reported. This approach has been applied to an Er:YAG laser, in-band pumped by an Er,Yb fiber laser, yielding 9.6 W of continuous-wave output at 1645 nm in a top-hat-like beam with beam propagation factor (M2)<2.1 for 24 W of incident pump power at 1532 nm. The corresponding slope efficiency with respect to incident pump power was 49%. The prospects of further scaling of output power and improved overall efficiency are considered.
authors.affiliation: Optoelectronics Research Center, University of Southampton, Southampton, UK. jwk7417@hanyang.ac.kr
authors.forename: J W
authors.initials: JW
authors.lastname: Kim
authors.forename: J I
authors.initials: JI
authors.lastname: Mackenzie
authors.forename: J R
authors.initials: JR
authors.lastname: Hayes
authors.forename: W A
authors.initials: WA
authors.lastname: Clarkson