Squeezed amplification in a nondegenerate parametric amplifier.

A linearized quantum analysis of an injection-seeded optical parametric amplifier is presented. When the amplifier is operated in a saturated gain regime, the amplified output intensity of the injected coherent-state signal becomes amplitude squeezed, and the signal-to-noise ratio improves. Above threshold, an injection-seeded parametric oscillator is found to generate more single-beam squeezing than an unseeded one. An amplitudesqueezed pump is shown to yield even better results.