High-repetition-rate ns optical parametric oscillator based on periodically poled potassium niobate

Summary form only given.Periodically poled nonlinear crystals are of particular advantage for realizing efficient optical parametric oscillators (OPOs). These materials provide high nonlinearity and quasi-phase-matched (QPM) frequency conversion within the range of optical transparency. So far, different materials have been investigated and compared. But none of these materials can be considered ideal for the wide range of applications. It is therefore of interest to develop and characterize further QPM materials. A new QPM material is periodically poled potassium niobate (PPKN). This crystal is considered to be very useful because of its large nonlinearity and wide transparency range in the near-infrared. Performance data of a PPKN OPO, obtained for a position of the focused pump radiation in the crystal which provides the lowest threshold, are presented.