title: Narrow-band 1 W source at 257 nm using frequency quadrupled passively Q-switched Yb:YAG laser.
abstract: We describe generation of 1.1 W of 257 nm emission by frequency quadrupling the 1030 nm emission from a compact passively Q-switched Yb:YAG laser. The laser utilized a volume Bragg grating to achieve a 0.1 nm linewidth required for UV-Raman spectroscopic applications, generated 100 kW peak power, 250 μJ pulses and 3.6 W of average power at 1030 nm. Fourth harmonic generation (FHG) was carried out using a 10 mm lithium triborate (LBO) crystal to generate 515 nm second harmonic with 70% conversion efficiency, followed by a 7 mm beta-barium borate (BBO) crystal to generate 257 nm fourth harmonic with 45% efficiency, resulting in an overall nonlinear conversion efficiency of 31%. Far-field and near-field of the FHG emission were characterized.
authors.forename: Lew
authors.initials: L
authors.lastname: Goldberg
authors.forename: Brian
authors.initials: B
authors.lastname: Cole
authors.forename: Chris
authors.initials: C
authors.lastname: McIntosh
authors.forename: Vernon
authors.initials: V
authors.lastname: King
authors.forename: A D
authors.initials: AD
authors.lastname: Hays
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Chinn