Silicon-Based MZI-Embedded Fano Resonator With Widely Tunable Slope Rate and Its Applications

A widely tunable Fano resonator based on a MachZehnder interferometer-embedded microring resonator (MZER) is proposed and fabricated on a silicon-on-insulator platform. Fano resonance with asymmetric line shapes can originate from the interference and coupling between resonant modes of the core MZER structure. Besides, the embedded equal-armed MachZehnder interferometer is used to tune ”ON” and ”OFF” states of Fano resonance at each operating wavelength. The measured results show that the fabricated MZER-based Fano resonator has a maximal extinction ratio of 67.34 dB and an ultra-wide tuning range of slope rate (SR) from -2166.08 dB/nm to 2817.54 dB/nm. Moreover, due to the ultra-sharp asymmetric line shape and the widely tunable SR, the proof-of-principle applications of such proposed MZER-based Fano resonator are experimentally demonstrated, including tunable slow and fast light generation with the group delay tuned from 946.36 ps to -568.26 ps, microwave frequency measurement with a resolution of ±0.15 GHz in a frequency measurement range of 5 GHz, and optical temporal differentiation of a Gaussian pulse with a temporal full width at half maximum of 90 ps.