Design, fabrication, and experiment of SOI-based embedded microring resonators exhibiting Fano lineshape

Abstract

An array of photonic integrated circuit (PIC)-based embedded microring resonators (EMRR) was designed, fabricated, and experimentally characterized for sensor and telecommunication applications. The photonic chip was fabricated using e-beam lithography. The physical parameters (coupling length and gap length) for both the ring-to-ring and bus-to-ring coupling sections were varied. Changing the physical parameters altered the measured free spectral range (FSR), resonance extinction ratio (ER), and full width half maximum (FWHM) values. Asymmetric resonance structures were observed, which were attributed to the Fano resonance phenomenon. These asymmetric resonances can be tuned by changing the microring's coupling coefficients.