The operating characteristics and experimental performance of continuous-wa
ve (cw) singly resonant optical parametric oscillators (ICSRO's) pumped int
ernally to the cavity of the pump laser are described. We outline the opera
ting principles, design criteria, and optimization procedure for maximum do
wnconversion and power extraction, and highlight the merits of the intracav
ity approach, including low input power requirement, potential for 100% dow
nconversion efficiency, high-power operational stability, and power scalabi
lity. The predicted behavior and many of the attractive practical features
of these devices are demonstrated in cw ICSRO's based on the birefringent n
onlinear materials KTiOPO4 and KTiOAsO4 and on the quasi-phase-matched nonl
inear materials periodically poled LiNbO3, RbTiOAsO4, and KTiOPO4, pumped i
nternally to cw Ti:sapphire- and diode-pumped solid-state lasers. Maximum e
xtracted infrared powers of 1.46 W, downconversion efficiencies of as much
as 90%, minimum input power thresholds of 310 mW, and wavelength tuning to
4 mu m in the mid-infrared are demonstrated. (C) 1999 Optical Society of Am
erica [S0740-3224(99)01809-3].