A resonantly enhanced four-wave parametric oscillator

The pump intensity required to achieve operation of an optical parametric oscillator based upon a resonantly enhanced four-wave mixing process is examined. The effects of a finite phase mismatch and of absorption of the generated waves are treated. Numerical calculations for an atomic system (Na) and two molecular systems (HCl, CO) reveal acceptably low pump intensity requirements and suggest that such a device is potentially an efficient, scalable source of tunable coherent radiation.