3 Optical components

3.1 Introduction

The basic optical-fibre link consisted of the source (laser or LED), the fibre and the detector, as was shown in Figure 1. Improvements in these components can increase the data rate, but the system is still a point-to-point transmission link and all signal processing, such as routeing, switching and regeneration, is done in electronics.

With the availability of devices that can process optical signals directly comes the possibility of using fibre in a more sophisticated way, leading eventually to an all-optical network.

This section considers some of the technology used and the components that have been created which might form the building-blocks of an optical network – or at least allow fibre to be used for slightly more than a point-to-point transmission link.