NON-LINEARITY COMPENSATION IN OPTICAL DEVICES AND TRANSMISSION SYSTEMS

摘要

A method of and apparatus for compensating optical non-linearity in optical devices and transmission systems. Two second order interactions are cascaded in phase-mismatched second harmonic generation to accumulate a non-linear phase shift of a fundamental wave. The non-linear phase shift can be set to provide a desired amount of non-linearity compensation. Compensation takes place in a compensating medium having a negative effective non-linear refractive index at the design operating conditions of the compensating medium. Compensators incorporating these principles may be incorporated as passive or active components in optical transmitters, repeaters or receivers . Active components may be tuned by varying the operating condition of the compensating medium, for example by controlling temperature or applied stres s. Embodiments of the invention use the compensator as pre- or post-compensator s in an optical amplifier, to eliminate or reduce self-phase modulation in the optical amplifier that occurs as a result of the Kerr effect.