title: 130-W picosecond green laser based on a frequency-doubled hybrid cryogenic Yb:YAG amplifier.
abstract: 130-W average-power picosecond green laser pulses at 514.5 nm are generated from a frequency-doubled hybrid cryogenic Yb:YAG laser. A second-harmonic conversion efficiency of 54% is achieved with a 15-mm-long noncritically phase-matched lithium triborate (LBO) crystal from a 240-W 8-ps 78-MHz pulse train at 1029 nm. The high-average-power hybrid laser system consists of a picosecond fiber chirped-pulse amplification seed source and a cryogenically-cooled double-pass Yb:YAG amplifier. The M(2) value of 2.7, measured at 77 W of second-harmonic power, demonstrates a good focusing quality. A thermal analysis shows that the longitudinal temperature gradient can be the main limiting factor in the second-harmonic efficiency. To our best knowledge, this is the highest-average-power green laser source generating picosecond pulses.
authors.affiliation: Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. kyunghan@mit.edu
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Hong
authors.forename: Chien-Jen
authors.initials: CJ
authors.lastname: Lai
authors.forename: Aleem
authors.initials: A
authors.lastname: Siddiqui
authors.forename: Franz X
authors.initials: FX
authors.lastname: Kärtner