Advances in optical transmission and electronic Integrated circuit technology have led to the emergence of the switched star network architecture1,2 In which high-capacity shared or concentrated optical feeder links radiate from a central service point to remote electronic switching points sited close to the subscriber. As information requirements expand at individual terminals, for example, through the growth of viewphone or video library services, additional feeder fibers are needed. Alternatively a wavelength division multiplex (WDM) scheme operating with channel spacings > 1 nm and using free running single-mode or multimode lasers could be used to meet this growth without the need for additional fibers (Fig. 1). WDM also offers the advantage of allowing several switch points to be served by a single-feeder fiber and could allow direct optical channels to selected subscribers.
© 1987 Optical Society of AmericaPDF Article