Wide-Range Tunable Microring Resonator Filter by Thermo-Optic Effect in Polymer Waveguide

A tunable Add/Drop filter is demanded for a scalable photonic network. A vertically coupled microring resonator (VCMRR) filter has many advantageous characteristics, such as a narrow bandwidth, the possibility of dense integration, and the ease of filter response synthesis. However, since a conventional tunable ring resonator filter utilized the thermo-optic effect of silica waveguides, the tunable wavelength range was not sufficiently wide. Thus, in this study, tunable vertically coupled microring resonator filters were demonstrated utilizing the large thermo-optic (TO) coefficient of polymer materials. The maximum center wavelength shift of 9.4 nm and the low power consumption of 60 mW were achieved.