A Tunable Multi-Port Fano Resonator Based on Mach-Zehnder Interferometers Coupling with Micro-Ring Resonators

Abstract

Fano resonance has an asymmetric and sharp resonance peak near the resonance wavelength, which can effectively enhance the all-optical signal processing capability and realize silicon photonic switches, sensors, and modulators. In this paper, a silicon photonic Fano resonator with Mach-Zehnder interferometer (MZI) structure coupling with micro-ring resonators (MRR) is designed. Two MRRs with different quality factors are coupled with two arms of an MZI, and the coupling zone is composed of two half-ring waveguides. Based on the transfer matrix method, the intrinsic and modulated transfer characteristics of the component are analyzed. By adjusting the optical amplitude and phase of MZIs and tuning the resonance wavelength of two MRRs, Fano resonance spectra are simulated at four output ports with the highest extinction ratios of 56.19 dB and maximum slope rates at 2175.74 dB/nm, and the transmission spectra of Fano resonance at the four output ports are experimentally demonstrated. As the four Fano resonance ports of the designed component have different performances, they can be used for various functions simultaneously. The advantage of the proposed scheme is the improvement of the multiplexing capacity and simultaneous utilization of the muti-port for the Fano resonator. Our four-port Fano resonator can be employed in the fields of optical switching, optical computing, and optical interconnect in the future.