Single-beam noise characteristics of quantum-correlated twin beams

摘要

We investigated the intensity noise spectra of a single beam of a pump-enhanced continuous-wave optical parametric oscillator (OPO), which was used to generate quantum-correlated twin beams, as a function of the pump power. With a triply (pump-, signal-, and idler-) resonant cavity, the oscillation threshold of our OPO was 8.5 +/- 1.3 mW and the measured slope conversion efficiency was 0.72 +/- 0.02. Twin beams with a power of 240 mW were generated at a pump power of 350 mW The relaxation oscillation frequencies, which depend on the pump power, were observed when the pump power of the OPO was 12.5-28 mW The experimental results confirm the predicted increase in OPO relaxation frequency with pump power. We experimentally inferred squeezing of the single-beam intensity, for the first time to our knowledge, by exploiting the nature of quantum noise that is dependent on loss. (C) 2004 Optical Society of America.