QUANTUM NOISE REDUCTION OF THE PUMP FIELD IN AN OPTICAL PARAMETRIC OSCILLATOR

摘要

Quantum noise properties of the pump field in an Optical Parametric Oscillator (OPO) are experimentally studied. We constructed a cw semimonolithic KTP triply resonant OPO, which had an extremely low oscillation threshold of 0.4 mW. The pump beam reflected back from this OPO is squeezed through strong parametric interactions. The observed intensity noise quickly changes in the bistable region of the OPO when the cavity length is scanned, and a quantum noise reduction of 24% is preliminarily demonstrated.