Demultiplexers for multichannel networks

The authors report the design of two prototype demultiplexing components for high capacity wavelength multiplexed networks. Two of a number of devices under development at STL are described. They have very different modes of operation and application. The rotating etalon channel selector use components that are commercially available now or are modified versions of such components. This has enabled a prototype device to be incorporated into a system demonstrator where the incoming data stream on different wavelength channels can be selected consecutively. The grating demultiplexer has the ability to select all wavelength channels simultaneously. The wavelength channels separated by the grating are received directly on linear arrays of small area detectors or on fibre arrays connected to discrete detectors. This device has the potential advantage of long term integration with the receiver electronics with consequent size and cost reduction and has no moving parts