2D Materials in Electro-optic Modulation: energy efficiency, electrostatics, mode overlap, material transfer and integration

TL;DR

This paper analyzes the physics and scaling laws of 2D material-based electro-optic modulators, highlighting energy efficiency improvements, temperature effects, mode overlap challenges, and a new method for integrating 2D materials into photonic chips.

Contribution

It provides a comprehensive analysis of 2D material electro-optic modulators, including scaling laws, temperature effects, and introduces a novel 2D material printing method for chip integration.

Findings

Energy per bit scales with device volume, enabling submicron plasmonic modulators.

Lowering temperature improves graphene modulator energy efficiency by 10x.

High index tunability of graphene compensates for small optical overlap in 2D modulators.

Abstract

Here we discuss the physics of electro-optic modulators deploying 2D materials. We include a scaling laws analysis showing how energy-efficiency and speed change for three underlying cavity systems as a function of critical device length scaling. A key result is that the energy-per-bit of the modulator is proportional to the volume of the device, thus making the case for submicron-scale modulators possible deploying a plasmonic optical mode. We then show how Graphenes Pauli-blocking modulation mechanism is sensitive to the device operation temperature, whereby a reduction of the temperature enables a 10x reduction in modulator energy efficiency. Furthermore, we show how the high index tunability of Graphene is able to compensate for the small optical overlap factor of 2D-based material modulators, which is unlike classical Silicon-based dispersion devices. Lastly we demonstrate a novel method towards a 2D material printer suitable for cross-contamination free and on-demand printing. The latter paves the way to integrate 2D materials seamlessly into taped-out photonic chips.