Hydex Glass and Amorphous Silicon for Integrated Nonlinear Optical Signal Processing

TL;DR

This paper reviews recent advances in nonlinear optical signal processing using Hydex glass and amorphous silicon, highlighting their advantages over silicon-on-insulator for integrated photonics applications.

Contribution

It provides a comparative analysis of Hydex glass and amorphous silicon as CMOS-compatible platforms for nonlinear optics, emphasizing their potential and challenges.

Findings

Hydex glass enables efficient on-chip optical frequency comb generation.

Amorphous silicon offers ultrafast optical pulse generation.

Both materials overcome limitations of silicon-on-insulator at telecom wavelengths.

Abstract

Photonic integrated circuits that exploit nonlinear optics in order to generate and process signals all-optically have achieved performance far superior to that possible electronically - particularly with respect to speed. Although silicon-on-insulator has been the leading platform for nonlinear optics for some time, its high two-photon absorption at telecommunications wavelengths poses a fundamental limitation. We review the recent achievements based in new CMOS-compatible platforms that are better suited than SOI for nonlinear optics, focusing on amorphous silicon and Hydex glass. We highlight their potential as well as the challenges to achieving practical solutions for many key applications. These material systems have opened up many new capabilities such as on-chip optical frequency comb generation and ultrafast optical pulse generation and measurement.