Plane-wave dynamics of optical parametric oscillation with simultaneous sum-frequency generation

The plane wave dynamics of a single-crystal upconversion optical parametric oscillators (OPO) with simultaneous sum-frequency generation (SFG) was studied. It was presumed that simultaneous phase-matching of the SFG and OPO processes were achieved by utilizing birefringent phase matching (BPM). Potential polarization geometries for collinear BPM led to four different sets of coupled mode equations depending on which field components were common to the two processes. The sets were designated as classes A through D. Classes A and D were efficient frequency upconverters. The performance of class A OPO's was limited by crystal properties whereas classes C and D was optimized by adjusting the polarization rotation angle