Simple, fast, yet rigorous modeling of a 355 nm pumped, doubly resonant, linear cavity Type I BBO OPO with spatial walk-off compensation and ISO 13694:2018 beam parameters

A commercially available linear cavity BBO OPO has been modeled with a new method and provides excellent agreement with experimental data. The OPO is doubly resonant linear cavity, uses a single- or dual-pass pump, and has two BBO crystals of 30 mm total length in a walk-off compensation design. The BBO crystals phase-match in a Type I geometry to produce 622 and 827 nm output, and the 355 nm pump experiences 73.778 mrad of spatial walk-off. The energy conversion efficiency agreement between the model and experiment is around 95% in both pump configurations. Neither trigonometric functions nor differential equation solvers are used.