Open AccessDigital predistortion for RSOAs as external modulators in radio over fiber systems
Author(s) -
Zhansheng Liu,
Manuel Violas,
Nuno Borges Carvalho
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.017641
Subject(s) - predistortion , radio over fiber , linearization , quadrature amplitude modulation , modulation (music) , amplifier , dynamic range , linearity , nonlinear distortion , qam , amplitude modulation , electronic engineering , distortion (music) , optics , optical amplifier , adjacent channel power ratio , computer science , radio frequency , nonlinear system , optical fiber , physics , bandwidth (computing) , telecommunications , frequency modulation , acoustics , bit error rate , engineering , channel (broadcasting) , laser , quantum mechanics
Reflective semiconductor optical amplifiers (RSOAs) can be used as external modulators in radio over fiber (RoF) links due to their amplification and modulation characteristics and colorless property. The nonlinear distortion of RSOA, however, limits its dynamic range. In this paper we demonstrate digital predistortion (DPD) linearization techniques to improve the linearity of RSOA external modulators. 64 quadrature amplitude modulation (QAM) signals are utilized to extract the model parameters. The dynamic AM/AM and AM/PM characteristics and power spectral densities of the modulated signals from the RSOA are demonstrated without and with DPD. Experimental results show clearly that the nonlinear distortion of RSOA external modulators in RoF links can be compensated using DPD linearization techniques.