Synthesis of multifunction optical filter based on digital signal processing method

By a digital signal processing method, a multifunction optical filter is synthesized. The filter is formed by a Mach–Zehnder interferometer with two cascaded double-ring resonators and a single-ring resonator on the two arms respectively. It can operate as a symmetrical interleaver, an asymmetrical interleaver with arbitrary duty cycles, a notch filter with a single notch point and a notch filter with two notch points. These four functions can be realized by choosing appropriate structural parameters. The configurable and tunable features make it useful in the future intelligent optical communication networks.