ULTRA-FAST TUNABLE OPTICAL FILTERS FOR WDM NETWORKS

One missing component in the next generation optical communications li nk is an ultra-fast tunable filter. This is a crucial element in dense wavelength division multiplexing systems. Here, a novel fiber loop co nfiguration is proposed, which operates as such a filter. The filter i mplementation is based upon currently available technologies. It is sh own that with the suggested technique, optical selective elements can be generated with a tuning speed of a few nanoseconds. This is three o rders of magnitude faster than other currently available filters. The filter can be designed as compact and is immunized to external instabi lities. Using compound configurations, the filter can be designed with a very wide range of filter finesse and free spectral range.