On-Chip Fano-Like Resonator With a High Slope and Low-Complexity Fabrication Processing

Fano resonators have attracted great attention due to their high extinction ratio and sharp asymmetric line shape. And Fano-like resonators have also been investigated and analyzed in plenty of fields, such as optical sensing, signal processing and so on. We propose and demonstrate a Fano-like resonator with a high slope rate (SR) and low-complexity fabrication processing. Our scheme is based on a symmetrical 2 × 2 multimode interferometer (MMI) and two parallel microring resonators (MRRs) which are sandwiched between the two branches of MMI. By appropriately tuning the voltages are applied on the lower branch of MMI and the right MRR, tunable SRs can be obtained. The SR of our scheme can vary from -115.04 dB/nm to -247.54 dB/nm, and the maximum SR is obtained when the power consumption of the micro-heater integrated on right MRR is 6.79 mW. Besides, the SR of our Fano-like resonator can be tuned between positive and negative within a wavelength range of 0.06 nm. Our scheme has the advantages of compact structure, low-complexity fabrication processing, and high flexibility. And it can be widely used in color filters, all-optical switches, and optical sensing.