Graphene oxide for enhanced nonlinear optics in low and high index contrast waveguides and nanowires

TL;DR

This paper demonstrates significant enhancement of four-wave mixing efficiency in doped silica waveguides by integrating graphene oxide layers, showing both experimental results and theoretical predictions for various waveguide geometries.

Contribution

The study introduces the integration of graphene oxide layers into waveguides to substantially improve nonlinear optical performance, with experimental validation and theoretical analysis.

Findings

Up to 9.5 dB FWM efficiency enhancement in silica waveguides with GO layers

Theoretical predictions of ~20 dB enhancement in various waveguide geometries

Potential for over 30 dB enhancement in silicon nanowires and slot waveguides

Abstract

We demonstrate enhanced four-wave mixing (FWM) in doped silica waveguides integrated with graphene oxide (GO) layers. Owing to strong mode overlap between the integrated waveguides and GO films that have a high Kerr nonlinearity and low loss, the FWM efficiency of the hybrid integrated waveguides is significantly improved. We perform FWM measurements for different pump powers, wavelength detuning, GO coating lengths, and number of GO layers. Our experimental results show good agreement with theory, achieving up to ~9.5-dB enhancement in the FWM conversion efficiency for a 1.5-cm-long waveguide integrated with 2 layers of GO. We show theoretically that for different waveguide geometries an enhancement in FWM efficiency of ~ 20 dB can be obtained in the doped silica waveguides, and more than 30 dB in silicon nanowires and slot waveguides. This demonstrates the effectiveness of introducing GO films into integrated photonic devices in order to enhance the performance of nonlinear optical processes.