title: Nonlinearity mitigation for high-speed optical OFDM transmitters using digital pre-distortion.
abstract: Optical orthogonal frequency-division multiplexing (OOFDM) signal is sensitive to nonlinear distortions induced by optical modulators. We propose and experimentally demonstrate a digital pre-distortion (DPD) algorithm to linearize the optical modulators including electro-absorption modulated lasers (EML) and Mach-Zehnder modulators (MZM) used in high-speed OOFDM transmitters. By using an adaptive DPD algorithm with a learning structure, the inverse transfer function of a modulator, which is based on a polynomial model, has been obtained. In the experiment, the performance improvements with and without considering the memory effects of the DPD model are illustrated. The two typical kinds of high-speed OOFDM signals with a bit rate up to 30-Gb/s have been implemented experimentally. The results show that the nonlinear distortion induced by optical modulators can be compensated by using the DPD algorithm to substantially improve the optical modulation index.
authors.affiliation: Institute of Photonics Technology, Jinan University, Guangzhou, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Bao
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Li
authors.forename: Jianping
authors.initials: J
authors.lastname: Li
authors.forename: Xinhuan
authors.initials: X
authors.lastname: Feng
authors.forename: Bai-ou
authors.initials: BO
authors.lastname: Guan
authors.forename: Guifang
authors.initials: G
authors.lastname: Li
mesh_terms: D016477:Artifacts; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*