Diffraction grating tuning of a high power, synchronously pumped PPLN OPO

Summary form only given. The use of a diffraction grating as a tuning element in a synchronously pumped optical parametric oscillator (SPOPO) offers a number of advantages. It provides an agile tuning mechanism (compared with temperature tuning of the nonlinear crystal) and it can, as we confirm here, suppress the cavity-length-dependent tuning behaviour that is normally seen in SPOPOs. It can also allow very close approach to degeneracy while maintaining singly resonant operation, as recently reported. Here we report on an examination of some unexplored aspects of the behaviour of a SPOPO equipped with a grating. In particular we examine the role of pulse-front-tilt induced by the grating. We show that its main effect is the introduction of an excess loss whose experimentally measured value agrees well with a simple analytical prediction.