Mode selection in doubly-resonant optical parametric oscillators

By using a computer model to calculate the threshold for each signal and idler mode-pair in doubly resonant optical parametric oscillators, we investigate the effects of the three principal tuning parameters (temperature, cavity length, and pump wavelength) on the mode selection. Through consideration of type I and type II noncritical phase-matched geometries for lithium triborate optical parametric oscillators, we illustrate that the tuning behavior depends on the difference between the refractive indexes experienced by the signal and idler fields