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

• Published in: Journal of lightwave technology Vol. 14; no. 11; pp. 2567 - 2574
• Main Authors: LIN, H.-T, KAO, Y.-H
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-11-1996; Institute of Electrical and Electronics Engineers
• Subjects: Circuits; Diode lasers; Exact sciences and technology; Fiber lasers; Fundamental areas of phenomenology (including applications); Laser noise; Lasers; Nonlinear distortion; Nonlinear equations; Optics; Physics; Predistortion; Semiconductor device noise; Semiconductor lasers; Semiconductor lasers; laser diodes; Signal generators; Semiconductor lasers; Optical transmission; Compensation; Performance characteristic; Rate equation; Cable television; Injection laser; Non linear distortion; Distributed feedback lasers
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/50.548156

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.