Tillman Karl A, Reid Derryck T
Ultrafast Optics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK.
Opt Lett. 2007 Jun 1;32(11):1548-50. doi: 10.1364/ol.32.001548.
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.
