Twin beams correlation and single beam noise for triply resonant KTP OPOs

Triply resonant optical parametric oscillations (TRO) are of interest for g enerating stable and highly correlated twin beams. Here we report intensity noise correlation and single beam spectra for pump powers up to 14 times t he threshold value. The correlation spectrum appear to be independent of th e pump power while the single beams exhibit a peak due to relaxation oscill ation. Such a resonance contributes to mask the squeezing predicted for dou ble resonant devices. The herein discussed TRO has shown a temporal stabili ty of the pump resonance longer than 6 h while delivering up to 4 mW per be am, fluctuating less than 5% over periods longer than half an hour. (C) 200 1 Published by Elsevier Science B.V.