Microwave-frequency carriers on optical fibres

Abstract

The use of microwave carrier frequencies in wideband optical-fibre networks is a promising new approach to the distribution of voice, data and video services to subscribers. This paper discusses the general features and design rules of microwave multiplexed wideband optical-fibre systems and reports on several specific systems developed at GTE Laboratories. These include transmission of 60 frequency modulated (FM) video channels multiplexed on carriers in the 2.7-5.2 GHz band, and the transmission of 20 frequency-shift-keyed (FSK) 100 Mb s -1 digital video channels in the 2-6 GHz band. A hybrid system is also described that transmits a 100 Mb s -1 baseband signal in addition to the 60 FM video channels. These transmission experiments illustrate the large bandwidth capability and design flexibility of microwave-multiplexed lightwave systems. As lightwave systems push towards larger and larger bandwidths, microwave-multiplexing may emerge as the more natural way to exploit the enormous bandwidth of lightwave components.