Four channel fibre grating demultiplexer

-..i........ j......... j........ i....... j......... f.........:....... f........:....................................................................................................................................................... The authors demonstrate a four channel all-fibre demultiplexer based on a 1x4 fused fibre coupler foUowed by strong fibre grating passband filters. With the success of erbium fibre amplifiers there is increased inter-est in wavelength division multiplexed (WDM) optical communi-cations systems. One of the most difficult devices to manufacture to the tight tolerances required for dense WDM applications is the demultiplexer (DEMUX). For example, a recent proposal to the International Telecommunication Union calls for channel spacings based on multiples of 100 GHz (-8A at 1. 5 5 ~ ). Here we demon-strate a simple four channel all fibre DEMUX which can meet such requirements.