GaAs photonic crystal cavity with ultra-high Q: microwatt nonlinearity at 1.55 $\mu $m

TL;DR

This paper demonstrates a GaAs photonic crystal nanocavity with an ultra-high quality factor of 700,000, enabling nonlinear optical effects at microwatt power levels, highlighting GaAs's potential for nonlinear photonics.

Contribution

The work presents the realization of a GaAs nanocavity with an ultra-high Q factor, showing feasibility and nonlinear functionality at very low power levels.

Findings

Achieved Q=700,000 in GaAs nanocavity

Nonlinear effects occur at microwatt power levels

GaAs exhibits larger two-photon absorption than silicon

Abstract

We have realized and measured a GaAs nanocavity in a slab photonic crystal based on the design by Kuramochi et al. [Appl. Phys.Lett., \textbf{88}, 041112, (2006)]. We measure a quality factor Q=700,000, which proves that ultra-high Q nanocavities are also feasible in GaAs. We show that, due to larger two-photon absorption (TPA) in GaAs, nonlinearities appear at the microwatt-level and will be more functional in gallium arsenide than in silicon nanocavities.