Silica arrayed waveguide dynamic gain equalization filter

The arrayed-waveguide dynamic gain equalization filter consists of a Mach-Zehnder interferometer with a demultiplexer-multiplexer pair connected by an array of equal-length waveguide containing thermooptic phase shifters in one arm. The relative phases between the upper, 'non-filtered' waveguide and the waveguides connecting the demultiplexer and multiplexer, each of which contains a band of the optical spectrum of interest, determine the transmissivity through the interferometer