Dynamic gain equalisation filter based on integrated optical transversal filter with asymmetric combiner

A compact dynamic gain equalisation filter on a silica-based planar lightwave circuit has been fabricated. The filter is based on the authors' newly developed optical transversal filter that uses an asymmetric combiner. This device flattened the amplified spontaneous emission spectrum of an erbium-doped fibre amplifier to a ripple of /spl sim/1 dB over a wavelength range of 30 nm.