Electrical Control of Silicon Photonic Crystal Cavity by Graphene

TL;DR

This paper demonstrates that electrostatic gating of graphene on a photonic crystal cavity significantly alters its optical resonance, enabling efficient, high-speed, low-power electro-optic modulation in integrated photonic devices.

Contribution

It introduces a novel graphene-photonic crystal device that achieves large resonance shifts and reflectivity changes through electrostatic gating, advancing integrated optoelectronic modulation.

Findings

Resonance linewidth changed by ~2nm

Resonance reflectivity changed by nearly 400% (6 dB)

Device potential for high-speed, low-power modulation

Abstract

Efficient conversion of electrical signal to optical signal in nano-photonics enables solid state integration of electronics and photonics. Combination of graphene with photonic crystals is promising for electro-optic modulation. In this paper, we demonstrate that by electrostatic gating a single layer of graphene on top of a photonic crystal cavity, the cavity resonance can be changed significantly. A ~2nm change in the cavity resonance linewidth and almost 400% (6 dB) change in resonance reflectivity is observed. In addition, our analysis shows that a graphene-photonic crystal device can potentially be useful for a high speed, and low power absorptive and refractive modulator, while maintaining a small physical footprint.