Photo-thermal tuning of graphene oxide coated integrated optical waveguides

TL;DR

This study explores how light power can reversibly or permanently modify graphene oxide films on optical waveguides through photothermal effects, revealing insights for photonic device engineering.

Contribution

It provides experimental analysis of power thresholds for GO reduction and compares effects of continuous and pulsed lasers on photothermal tuning.

Findings

Identified power thresholds for reversible and permanent GO reduction.

Confirmed that photothermal tuning depends mainly on average laser power.

Characterized inhomogeneous GO reduction along waveguides.

Abstract

We experimentally investigate power sensitive photothermal tuning (PTT) of two dimensional (2D) graphene oxide (GO) films coated on integrated optical waveguides. We measure the light power thresholds for reversible and permanent GO reduction in silicon nitride (SiN) waveguides integrated with 1 and 2 layers of GO. Raman spectra at different positions of a hybrid waveguide with permanently reduced GO are characterized, verifying the inhomogeneous GO reduction along the direction of light propagation through the waveguide. The differences between the PTT induced by a continuous wave laser and a pulsed laser are also compared, confirming that the PTT mainly depend on the average input power. These results reveal interesting features for 2D GO films coated on integrated optical waveguides, which are of fundamental importance for the control and engineering of GO properties in hybrid integrated photonic devices.