Abstract: An optical communication system and method are provided which utilize dispersion-induced FM to AM conversion with nonlinearity-induced AM stabilization. The system and method utilize a frequency modulated optical signal transmitter, a fiber span, an optical receiver which receives the transmitted optical signal and detects an AM signal resulting from dispersion-induced energy overlaps and voids in the optical signal, and one or more in-line amplifiers spaced within the optical fiber span. By adjusting the number, position and/or output power levels of the in-line amplifiers, stabilization of the energy voids and overlaps and resulting AM signal can be achieved, yielding a substantial increase in achievable transmission distance at a given bit rate.

Abstract: The present invention provides an apparatus and method for performing polarization-insensitive four-photon mixing of optical signals. The polarization-insensitive optical mixer includes a polarization splitter for splitting an optical signal into parallel and perpendicular polarization components, different mixing paths for mixing a pump signal of like polarization with each of the parallel and perpendicular components in a nonlinear mixing device, and a polarization combiner for combining the resulting mixing products. Certain of the mixing products represent phase conjugates of the input optical signal, and are therefore useful in compensating for chromatic distortion in optical fiber.

Abstract: The present invention provides an apparatus and method for achieving bit rate distance products on the order of 200 Tbits/s-km in non-soliton optical communication using optical phase conjugation. The apparatus and method utilize phase conjugation and adjustments of in-line amplifier number, spacing, and/or output power in order to compensate for the interaction between first order dispersion and fiber nonlinearity dispersion effects in an optical fiber span. The present invention provides additional techniques for adjusting system parameters, such as dispersion-length products of first and second portions of the fiber span, in order to compensate for changes in first order dispersion resulting from non-zero second order dispersion. The method and apparatus also provide an improved multi-channel optical phase conjugation system design.