Design and Experimental Evaluation of Active-Passive Integrated Microring Lasers: Threshold Current and Spectral Properties

The relation between the structural parameters and the operating characteristics of microring lasers is examined through theoretical estimations, waveguiding simulations, and experimental measurements. The effects of ring radius, waveguide profile, and overall geometry on the coupling efficiency and subsequently on threshold and spectral characteristics are thoroughly investigated. Coupling efficiency is calculated through 3-D finite difference in time domain methods. Fabricated devices consist of active microrings integrated with passive bus waveguides using wafer bonding techniques.