Generation of bright squeezed light at 1.06 mu m using cascaded nonlinearities in a triply resonant cw periodically-poled lithium niobate optical parametric oscillator - art. no. 033815

We have used an ultralow threshold continuous-wave optical parametric oscil lator (OPO) to reduce the quantum fluctuations of the reflected pump beam b elow the shot noise limit. The OPO consisted of a triply resonant cavity co ntaining a periodically poled lithium niobate crystal pumped by a Nd:YAG (y ttrium. aluminum garnets) laser and giving signal and idler wavelengths clo se to 2.12 mum and a threshold as low as 300 muW. We detected the quantum f luctuations of the pump beam reflected by the OPO using a slightly modified homodyne detection technique. The measured noise reduction was 30% (inferr ed noise reduction at the output of the OPO 38%).