Abstract
A novel scheme for continuous-wave quantum nondemolition (QND) detection of optical-amplitude quadratures is implemented using a degenerate optical parametric amplifier. A monolithic ring resonator with optimizable frustrated total internal reflection coupling is used. Signal and meter output beams are squeezed by 0.5 dB and 2.2 dB, and 38% correlated. This implies the first realization of individually squeezed twin beams, as well as quantum state preparation ability for both output beams. A quantum optical tap efficiency Ts + Tm = 1.08 is achieved. The all-solid-state system was completely stabilized and continuously operated as a QND device for up to 36 hours.