Phase-conjugate pump dithering for high-quality idler generation in a fiber optical parametric amplifier

We experimentally demonstrate a simple technique to cancel the idler broadening in a fiber optical parametric amplifier (OPA) by using two pumps phase-modulated 180/spl deg/ out of phase, one of them being obtained by four-wave mixing in an auxiliary fiber. The resulting OPA idler quality is comparable to that of the output signal.