Photo-thermal tuning of graphene oxide thin film coated integrated
optical waveguides
Abstract
We experimentally investigate power-sensitive photo-thermal 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’s properties in hybrid
integrated photonic devices.