title: Monolithic optical parametric oscillator using chirped quasi-phase matching.
abstract: We describe a highly efficient monolithic, Q-switched, nanosecond optical parametric oscillator based on a magnesium-oxide-doped periodically poled lithium niobate crystal and containing multiple quasi-phase-matched gratings. The crystal consisted of a single unchirped grating and five gratings containing progressively increasing amounts of longitudinal chirp. The monolithic design makes the device highly compact, stable, and robust, and it demonstrated a pump-to-signal conversion efficiency of around 50%, generating 50 microJ pulses at 1.55 microm with a spectral bandwidth of 20 nm. Sonogram traces are presented showing the effect of crystal chirp on the temporal and spectral performance.
authors.affiliation: Ultrafast Optics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK.
authors.forename: Karl A
authors.initials: KA
authors.lastname: Tillman
authors.forename: Derryck T
authors.initials: DT
authors.lastname: Reid