Analysis and Applications of Nonlinearities in Optical Fibres in Wavelength Division Multiplexed Systems

摘要

Optical nonlinearities play a major role in optical fibre with respect to transmission capacity and performance of the system. This degrades the system performance, especially in wavelength division multiplexing (WDM) systems, where several channels co-exist in the same fibre and propagating simultaneously, resulting in high optical intensities. They can result in pulse distortion referred to as self phase modulation (SPM), cross phase modulation (XPM), crosstalk between channels, and four wave mixing (FWM). However, these non-linearities also have many useful applications, especially for the implementation of all-optical functionalities in optical networks. In this paper, we briefly review the different kinds of optical nonlinearities encountered in fibres, identify the essential materials and fibre parameters that determine them. The paper simulates two channel WDM optical communication systems in single mode fibre over long haul of 100 km to investigate the effect of SPM, XPM and FWM. Their thresholds, managements and applications are also discussed; and comparative study of these effects is presented.