CW Fiber Optical Parametric Amplifier with Net Gain and Wavelength Conversion Efficiency Greater than One

In order to be useful in a wide range of communication applications, fiber optical parametric amplifiers (OPA’s) and wavelength converters should operate on a cw basis. Furthermore, conversion efficiency Gi should be greater than or equal to one, in order to avoid the substantial signal-to-noise ratio degradation which occurs if Gi ≪ 1. Currently silica-based fibers have the best characteristics for making fiber OPA’s. However, owing to the relative weakness of the third-order nonlinear susceptibility in such fibers, amplification by fiber OPA’s requires a high pump power and/or a large fiber length. Pulsed amplification has been reported by a number of groups. CW fiber parametric amplification with a 17 dBm pump has been reported, but with a gain insufficient to overcome fiber loss [1].