Compensation for nonlinear distortion of optical OFDM signals induced by electro-absorption modulated lasers with digital predistortion

Abstract

In this paper, we demonstrated a digital predistortion (DPD) algorithm to linearize an electro-absorption modulated laser (EML) used to modulate a 40-Gbps orthogonal frequency division multiplexing (OFDM) signal onto an optical carrier. We characterized the EML as a nonlinear model based on memoryless polynomials. The nonlinear coefficients were estimated by a linear method. And the predistortion function of the EML was achieved with these estimated coefficients. The experimental results indicated that the DPD algorithm is an efficient method to compensate for the nonlinear distortion in EMLs.