Stable bright squeezed light by optical parametric deamplification in a semi-monolithic resonator

Summary form only given. We report on the development and characterization of a novel source of bright squeezed light based on parametric deamplification of a seed wave. The device is both simple to implement and exhibits excellent temporal stability. A diode-pumped Nd:YAG laser serves as the primary source of the system. Most of the laser power is frequency doubled in a semi-monolithic MgO:LiNbO/sub 3/ standing wave cavity to provide the pump wave at 532 nm for a dual port degenerate optical parametric amplifier (DOPA). The DOPA resonator consists of a MgO:LiNbO/sub 3/-crystal and a concave external mirror mounted on a piezoelectric transducer (PZT). A seed wave at 1064 nm is resonantly injected through the spherically polished endface of the crystal, which is coated with a high reflector at 1064 and 532 nm. Degenerate operation is achieved by stabilization of the cavity length such that the seed wave is resonant. The external mirror, which is highly transmitting at 532 nm and has a reflectivity of 96% at 1064 nm, is used both for incoupling of the pump wave and for extraction of the parametrically deamplified and squeezed output infrared wave. The relative phase between pump and seed wave is stabilized to maximum deamplification by a lock-in technique to ensure stable amplitude squeezing of the DOPA.