Fano-resonance-based Mach-Zehnder optical switch employing dual-bus coupled ring resonator as two-beam interferometer

Abstract

A kind of Mach-Zehnder optical switch with a dual-bus coupled ring resonator as a two-beam interferometer is proposed and investigated. The analysis based on the transfer matrix method shows that a sharp asymmetric Fano line shape can be generated in the transmission spectra of such a configuration, which can be used to significantly reduce the phase change required for switching. Meanwhile, it can also be found that complete extinctions can be achieved in both switching states if the structural parameters are carefully chosen and the phase bias is properly set. Through tuning the phase difference between the arms of the Mach-Zehnder interferometer, complete extinction can be easily kept within a large range of the ring-bus coupling ratios in the OFF state. By properly modulating the phase change in the ring waveguide, the shift of the resonant frequency and the asymmetry of the transmission spectra can be controlled to finally enable optical switching with a high extinction ratio, even complete extinction, in the ON state. The switching functionality is verified by the finite-difference time-domain simulation.

Tunable Fano resonances based on two-beam interference in microring resonator

“…A lot of theoretical and experimental works have been done to obtain the sharp asymmetric Fano resonances. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] In Ref. 2, Fan proposed the side-coupled waveguide-cavity systems to generate sharp Fano resonance and proved that its performance is greatly improved compared to the counterpart with symmetric line shape.…”

Study of silicon photonics based on standard CMOS foundry

“…With carefully design and fabrication, we achieved a Mach-Zehnder switch with an extinction ratio about 20 dB [8]. In order to improve the performance, a Fanoresonance-based Mach-Zehnder configurature with a dual-bus coupled ring resonator as two-beam interferometer is proposed and studied [9].…”

Reversible Image Contrast Manipulation with Thermally Tunable Dielectric Metasurfaces

“…FRs generally arises from the interference of a narrow resonance with a broader background . Fano resonant metasurfaces have been recently studied for other applications such as sensing, optical switches, and narrow‐band filters . Here, for the first time, we merge FR nature and thermo‐optical characteristic of a metasurface to reversibly switch images with high intensity contrast.…”