Kerr and free-carrier ultrafast all-optical switching of GaAs/AlAs nanostructures near the three-photon edge of GaAs

TL;DR

This paper demonstrates ultrafast all-optical switching of GaAs/AlAs nanostructures using Kerr effect and free carriers, with measurements of nonlinear coefficients near the three-photon absorption edge, enabling control of high-Q photonic cavities.

Contribution

It provides new measurements of Kerr and three-photon absorption coefficients in GaAs near the three-photon edge, enabling efficient all-optical switching of high-Q nanocavities.

Findings

Kerr effect can switch high-Q GaAs/AlAs cavities.

Measured Kerr coefficients over a broad wavelength range.

Determined three-photon absorption coefficients at near-infrared wavelengths.

Abstract

We performed non-degenerate pump-probe experiments on a GaAs/AlAs photonic structure. We switched the photonic properties using the optical Kerr effect and free carriers excited by three photon absorption. From these measurements we extracted the non-degenerate Kerr coefficients over a broad wavelength range and we extracted the three photon absorption coefficient for GaAs at three wavelengths in the near infrared. We show that the optical Kerr effect is large enough to switch a cavity resonance with a high \emph{Q} ($Q>1000$) photonic cavity.