Nonlinear distortions and compensations of DFB laser diode in AM-VSB lightwave CATV applications

Author

Lin, Hung-Tser ; Kao, Yao-Huang

Author_Institution

Dept. of Commun. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

14

Issue

11

fYear

1996

fDate

11/1/1996 12:00:00 AM

Firstpage

2567

Lastpage

2574

Abstract

The nonlinear distortions of a directly modulated laser diode applied to AM-VSB lightwave CATV systems are studied from the viewpoint of rate equations. A simple method for calculating composite second-order distortion (CSO) is proposed, which is called the quasidynamic approach. The contribution to nonlinearity from fiber dispersion and laser chirping is also discussed. The dependences on the variations of parameters of rate equations are investigated to determine the dominant factor for CSO degradation. This approach explains quite well the experimental results and suggests a method for constructing a predistortion circuit with at least 10 dB improvement

Keywords

amplitude modulation; cable television; chirp modulation; compensation; distributed feedback lasers; harmonic distortion; laser beams; laser noise; optical fibre dispersion; optical modulation; rate distortion theory; semiconductor lasers; television interference; AM-VSB lightwave CATV; DFB laser diode; composite second-order distortion; directly modulated laser diode; distortion compensation; fiber dispersion; laser chirping; nonlinear distortions; predistortion circuit; quasidynamic approach; rate equations; second harmonic distortion; Circuits; Diode lasers; Fiber lasers; Laser noise; Nonlinear distortion; Nonlinear equations; Predistortion; Semiconductor device noise; Semiconductor lasers; Signal generators;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.548156

Filename

548156