title: Mode spectrum of multi-longitudinal mode pumped near-degenerate OPOs with volume Bragg grating output couplers.
abstract: Spectral requirements for the first stage OPO used to pump a tandem ZGP mid-infrared OPO are theoretically investigated. Based on these requirements we demonstrate a singly-resonant type-I OPO including periodically poled KTiOPO(4) and volume-Bragg gratings as output couplers. Singly resonant oscillation is demonstrated very close to degeneracy, where signal and idler spectra are not well separated. Investigations of the longitudinal mode spectrum and the idler spectrum with high resolution using a scanning Fabry-Perot interferometer show the essential role played by the phase correlations of the multi-longitudinal mode Q-switched pump laser in formation of the nonresonant idler spectrum.
authors.affiliation: Laser Systems Group, FOI - Swedish Defence Research Agency, PO Box 1165, 581 11 Linköping, Sweden. mahe@foi.se
authors.forename: Markus
authors.initials: M
authors.lastname: Henriksson
authors.forename: Lars
authors.initials: L
authors.lastname: Sjöqvist
authors.forename: Valdas
authors.initials: V
authors.lastname: Pasiskevicius
authors.forename: Fredrik
authors.initials: F
authors.lastname: Laurell
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity