Title :
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
fDate :
11/1/1996 12:00:00 AM
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;
Journal_Title :
Lightwave Technology, Journal of
