Regenerative oscillation and four-wave mixing in graphene optoelectronics

TL;DR

This paper reports the first observation of ultralow power optical bistability, regenerative oscillations, and four-wave mixing in graphene-silicon hybrid devices, highlighting their potential for ultrafast optical applications.

Contribution

It demonstrates novel nonlinear optical phenomena in graphene-silicon hybrid devices enabled by graphene's large nonlinearities and high Q/V photonic cavities.

Findings

Ultralow power resonant optical bistability observed

Self-induced regenerative oscillations detected

Coherent four-wave mixing demonstrated

Abstract

The unique linear and massless band structure of graphene, in a purely two-dimensional Dirac fermionic structure, have led to intense research spanning from condensed matter physics to nanoscale device applications covering the electrical, thermal, mechanical and optical domains. Here we report three consecutive first-observations in graphene-silicon hybrid optoelectronic devices: (1) ultralow power resonant optical bistability; (2) self-induced regenerative oscillations; and (3) coherent four-wave mixing, all at a few femtojoule cavity recirculating energies. These observations, in comparison with control measurements with solely monolithic silicon cavities, are enabled only by the dramatically-large and chi(3) nonlinearities in graphene and the large Q/V ratios in wavelength-localized photonic crystal cavities. These results demonstrate the feasibility and versatility of hybrid two-dimensional graphene-silicon nanophotonic devices for next-generation chip-scale ultrafast optical communications, radio-frequency optoelectronics, and all-optical signal processing.