A highly accurate engineering of silicon integrated microring resonators based on the nanofabrication technique

Abstract

ABSTRACT In this work we present our theoretical and experimental study on the technique for the ne modi cation of asilicon integrated microring resonator spectral response. The method involves the local atomic layer depositionof a thin TiO 2 overlayer and is applicable for standard nanophotonic waveguides. The approach is based on thedispersion management due to the speci c dispersion properties brought by the thin TiO 2 lm deposition. Inaddition, the technique is able to partially compensate the fabrication imperfections and reduce the propagationlosses.Keywords: Silicon photonics, ring resonators, optical waveguides, thin lms, atomic layer deposition, chromaticdispersion 1. INTRODUCTION Optical microring resonators are well established fundamental components in modern photonic integrated cir-cuits. They constitute lters, switches, and sensing schemes, 1 giving means to build up optical integrated logic.Although the mass manufacturing lithography techniques are highly advanced for microring resonators, thereis a great interest in further optimization of their operation properties. In order to preserve high repeatabilityof the ring resonator manufacturing, a ne control of the fabrication tolerances is crucial at both lithographyand etching stages. The problem is often relevant for ring resonators fabricated by optical lithography as theyneed some additional processing to match the speci cations. The post-processing stage typically includes themodi cation of the waveguide geometry such as, e.g., etching of the waveguide core or a deposition of an extracladding.