We demonstrate a low-threshold twin-beam generator using a cw triply r
esonant optical parametric oscillator consisting of two coupled caviti
es: one that resonates the signal and idler waves and the other the pu
mp field. An intensity correlation of 5.5 dB was observed at 3 MHz for
a type-II phase-matched KTP optical parametric oscillator. (C) 1998 O
ptical Society of America.