Design and Analysis of Nonvolatile GSST-based Modulator Utilizing Engineered Mach-Zehnder Structure with Graphene Heaters

TL;DR

This paper proposes a novel nonvolatile Mach-Zehnder modulator using GSST phase change material and graphene heaters, addressing design challenges caused by phase transition effects for improved optical modulation.

Contribution

It introduces loss-balancing and pre equalization design methods for GSST-based MZMs with graphene heaters, enabling high-performance nonvolatile optical modulation.

Findings

Effective loss balancing improves modulator performance.

Pre equalization enhances phase transition control.

Design methods enable nonvolatile reconfigurable PICs.

Abstract

Photonic integrated circuits (PICs) are the foundation of on-chip optical technologies. Mach-Zehnder modulators are appealing building blocks of PICs which mostly rely on weak and volatile optical effects in materials. In contrast, phase change materials such as GSST are promising candidates to realize efficient and nonvolatile reconfigurable optical devices. However, the phase transitions of PCMs are accompanied by large changes in the imaginary parts of their refractive indices which make the design of MZMs challenging. In this paper, two interesting design methods named as loss-balancing and pre equalization are introduced to propose high performance GSST based MZMs. In this regard, a GSST based waveguide with graphene as a microheater is proposed which plays the role of configurable active waveguide in both the introduced methods.