Spread spectrum communication network using optical signal processing

A novel implementation of an all-optical signal processor is proposed for local area networks. The scheme based on a bipolar tap implementation incorporating a nonlinear component, and utilising a spread spectrum technique, allows multiple access to local area networks. Recently a spread spectrum technique, referred to as code division multiple access (CDMA), has been described for local area networks. In this scheme each user is assigned orthogonal codes, which results in a substantial increase in the bandwidth of the transmitted signal. The bandwidth requirements of this technique can only be supported by widebandwidth channels such as fibre-optics, as well as requiring widebandwidth signal processors at the receiver. Conventional receivers for CDMA use electronic processors, but much effort is focussed into the development of all-fibre and integrated optical devices which could realise all optical processing. Maximum potential of techniques such as CDMA can only be realised if high bandwidth, all-optical signal processors are available