Three-dimensional rendering (IMAGE) Optica Caption Three-dimensional rendering of the frequency translating add/drop filter showing two coupled active microring resonators, interferometric input/output waveguides, metal wires connected to electro-optic and thermo-optic phase shifters, and vertical grating couplers. Credit Hayk Gevorgyan, Boston University Usage Restrictions N/A License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.