Issues and opportunities for tunable chromatic dispersion compensation in 10- and 40-Gbps applications

Abstract

The problem of chromatic dispersion is well known and has long been a limiting effect in optical networks. The traditional solution for dealing with chromatic dispersion - dispersion compensating fiber - has a variety of drawbacks that limit its effectiveness in some 10 Gbps applications and in many 40 Gbps applications. Several new classes of tunable dispersion compensators have recently been developed to address these limitations. We will first review the causes and manifestations of chromatic dispersion and discuss the impact of residual chromatic dispersion, including its dependencies on transmission distance, bit rate, and data bandwidth. Then we will discuss the factors that create the need for tunability and examine how tunable dispersion compensators address these needs. Finally, we will review the technology behind currently available solutions for tunable chromatic dispersion compensation, including nonlinearly chirped fiber Bragg gratings, and contrast their advantages and disadvantages relative to the traditional solution of dispersion compensating fiber.