title: Cavity-enhanced generation of 6 W cw second-harmonic power at 532 nm in periodically-poled MgO:LiTaO3.
abstract: We report on efficient cw high-power second harmonic generation in a periodically poled LiTaO3 crystal placed in a resonant enhancement cavity. We tested three configurations, differing in the coupling mirror reflectivity, and a maximum conversion efficiency of about 76%, corresponding to 6.1 W of green light with 8.0 W of fundamental power, was achieved. This is, to the best of our knowledge, the highest cw power ever reported using a periodically-poled crystal in an external cavity. We observed photo-thermal effect induced by photon absorption at the mirrors and in the crystal, which however does not affect stable operation of the cavity. A further effect arises for two out of the three configurations, at higher values of the input power, which degrades the performance of the locked cavity. We suggest this effect is due to the onset of competing nonlinearities in the same crystal.
authors.affiliation: INO-CNR, Istituto Nazionale di Ottica, Sezione di Napoli, and LENS, European Laboratory for Nonlinear Spectroscopy Via Campi Flegrei 34, I-80078 Pozzuoli, NA, Italy.
authors.forename: Iolanda
authors.initials: I
authors.lastname: Ricciardi
authors.forename: Maurizio
authors.initials: M
authors.lastname: De Rosa
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rocco
authors.forename: Pietro
authors.initials: P
authors.lastname: Ferraro
authors.forename: Paolo
authors.initials: P
authors.lastname: De Natale
mesh_terms: D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D008094:Lithium / Q000737:chemistry* / Q000528:radiation effects; D008277:Magnesium Oxide / Q000737:chemistry / Q000528:radiation effects; D055096:Optical Devices; D010087:Oxides / Q000737:chemistry* / Q000528:radiation effects; D013635:Tantalum / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D010087:Oxides; C473347:lithium tantalate oxide; D008277:Magnesium Oxide; D013635:Tantalum; D008094:Lithium