Testing, characterization and engineering analysis of an array of photonic integrated circuits-based optical ring resonators with varying ring radius, coupling gap, and coupling angle

Abstract

We report on the experiment, testing, characterization, and performance of an array of pulley-type optical microring resonators (MRR) fabricated on a passive silicon-on-insulator (SOI) platform using e-beam lithography. The waveguide dimensions are 220 nm height and 500 nm width. These MRRs were designed with different parameter values such as (i) ring radius, (ii) gap length, (iii) coupling angle to obtain experimentally the optimal values. We performed intensity-vs-wavelength measurements for over 206 MRR-based photonic circuits by sweeping the wavelength of the tunable laser from 1527 nm to 1567 nm. We compared the measured free spectral range (FSR) and average extinction ratio (ER) with the designed MRR performance. 127 out of the 206 samples had measurable resonance ER. It was determined that the gap length parameter largely correlates to the MRR ER which was supported by doing principal component analysis (PCA).