Abstract

Theoretical calculations have been made for an optical parametric oscillator (OPO) containing, in addition to the OPO crystal, a second crystal for sum-frequency generation (SFG) of the pump and the OPO signal. The objective is efficient tunable generation of the sum frequency. Only the OPO signal oscillates in the cavity. The configuration where the SFG crystal precedes the OPO crystal is predicted to give superior operation. Nearly complete pump depletion can occur for over a factor-of-12 variation in the pump intensity. Other regimes of operation display period-doubling routes leading to chaotic solutions. Power loading in the OPO crystal at saturation can be less than the incident pump power. However, the SFG crystal reduces the small-signal gain, and transmission of the long-wavelength idler radiation limits the choice of OPO crystal. With an AgGaS₂ OPO crystal and a KTP SFG crystal for conversion of 1064 nm to 589 nm radiation needed for guide-star generation in mesospheric sodium, the intensity conversion efficiency is calculated to be 86.6%.

© 1992 Optical Society of America