Optimization of the resonant wave output coupling of a singly resonant optical parametric oscillator using an intracavity plate

We present a technique allowing us to optimize the output coupling of the resonant wave of a singly resonant optical parametric oscillator (SRO). By inserting a silica plate inside the cavity and tilting it around the Brewster angle, the output coupling of the SRO can be easily varied. This technique combines in principle the advantage of an efficient output coupling together with the possibility of controlling the frequency of the resonant wave of the SRO. We use this plate inside a 532-nm-pumped SRO to extract 1.6W at 1.2 μm with a pump depletion of 80 %. We also show the possibility of determining the intracavity loss of the OPO, which is a useful parameter regarding its optimization.