Controlling the phase of a femtosecond optical parametric oscillator via coherent mixing of the pump-generated supercontinuum and an OPO subharmonic

We have shown by measuring the beat frequency between the supercontinuum (SC) and the optical parametric oscillator (OPO) 2/spl omega//sub s/ subharmonic, we can observe and control the relative phase slip between the pump and signal. The relative phase slip can be controlled for a large OPO signal range since the 2/spl omega//sub s/ subharmonic is mixed with the SC. It is possible to use the SC to extend carrier-envelope locking so that both the Ti:sapphire pulse and OPO signal are locked to an absolute reference.