ABSTRACT
Optical fibre communications has been one of the major users of lasers and their related optical components, such as amplifiers, modulators and receivers [1]. The optical carrier frequency is in the near-infrared spectrum and it can be modulated to provide a greater overall bandwidth than any other means of data transmission [2]. Progress in the technology has been very rapid and the subject has had a history of recordbreaking propagation lengths, information capacities and numbers of customers served. Consequently, the effect that optical communications has had on society has been revolutionary [3].
