Silicon-Family Materials and Waveguides

Abstract

The optical properties of three silicon-family materials—silicon, silicon nitride, and silica—are introduced. These materials have attracted tremendous interest from academia and industry and gained widespread applications. This chapter discusses the optical properties of these materials. In parallel to the silicon-family materials, other new opto-electronic materials have emerged, such as 2D materials, thin-film lithium niobate, and alumina. Hybrid integration with these materials on the silicon platform is of great interest to achieve new functions or superior performances. Subsequently, we examine the optical waveguide properties made of silicon-family materials and hybrid materials, covering the waveguide dimension, losses, and dispersion. In detail, we discuss nano-scale silicon wire waveguides, silicon nitride waveguides, multi-layer waveguides, micro-scale GeO2-doped silica waveguides, graphene–silicon waveguides, thin-film lithium niobate on silicon, and alumina on silicon for applications ranging from the infrared to the ultra violet regimes.