title: High-pulse-energy mid-infrared fractional-image-rotation-enhancement ZnGeP2optical parametric oscillator.
abstract: A high-energy mid-infrared ZnGeP2(ZGP) optical parametric oscillator (OPO) based on the nonplanar fractional-image-rotation enhancement resonator pumped by a 2.05 μm Ho3+:YLF laser is presented. Up to 120 mJ pulse energy in a rotationally symmetric beam is generated in the 3-5 μm wavelength range at 1 Hz repetition rate. Slope efficiencies of up to 78% are achieved with respect to the pump pulse energy incident onto the ZGP crystal. The OPO pulses have a duration close to 15 ns, corresponding to a maximum peak power of 8 MW. A measurement of M2dependence on pump beam diameter is presented.
authors.forename: Marc
authors.initials: M
authors.lastname: Eichhorn
authors.forename: Martin
authors.initials: M
authors.lastname: Schellhorn
authors.forename: Magnus W
authors.initials: MW
authors.lastname: Haakestad
authors.forename: Helge
authors.initials: H
authors.lastname: Fonnum
authors.forename: Espen
authors.initials: E
authors.lastname: Lippert