Analysis of the doubly resonant optical parametric oscillator without power-dependent reflections

We present an analysis of the steady-state oscillation of a doubly resonant optical parametric oscillator in which there are no power-dependent reflections of pump power from the oscillator cavity. There is no limiting of the pump power passing through such an oscillator and 100-percent conversion efficiency is obtained for pumping four times threshold. Previous experiments are discussed in light of these results.