Predistortion Compensation of Nonlinearities in Channelized RF Photonic Links Using a Dual-Port Optical Modulator

High dynamic range is a key requirement in analog applications. In multichannel optical signal processing applications, a wideband radio-frequency signal suffers from distortion from both in-channel and out-of-channel signals due to nonlinear modulator behavior. We demonstrate experimentally the compensation of nonlinearities occurring due to out-of-channel “cross-modulation” with a novel predistortion technique using a dual-port modulator. Predistortion compensation results in suppression of distortion by more than 25 dB.