RETRIEVING SQUEEZING FROM CLASSICALLY NOISY LIGHT IN 2ND-HARMONIC GENERATION

We report the results of a study of the quantum noise properties of a squeezing system involving a three-level laser pumping tare similar se cond-harmonic-generating crystals. We show that squeezing that has bee n obscured by intensity and phase noise from the pump laser may be ret rieved by difference detection of both second-harmonic outputs. Simila rly, the squeezed vacuum formed by combining the two outputs on a 50/5 0 beam splitter will be squeezed at frequencies that are classically n oisy in the individual beams.