Local tuning of photonic crystal cavities using chalcogenide glasses

TL;DR

This paper presents a technique for locally tuning photonic crystal cavities by photodarkening a chalcogenide glass layer, enabling precise resonance adjustments with minimal quality factor loss.

Contribution

The authors introduce a novel postproduction tuning method using chalcogenide glasses to adjust photonic device resonances with high precision and minimal impact on device quality.

Findings

Achieved up to 3 nm resonance tuning at 940 nm

Only 5% deterioration in cavity quality factor

Broad applicability for photonic device postproduction tuning

Abstract

We demonstrate a method to locally change the refractive index in planar optical devices by photodarkening of a thin chalcogenide glass layer deposited on top of the device. The method is used to tune the resonance of GaAs-based photonic crystal cavities by up to 3 nm at 940 nm, with only 5% deterioration in cavity quality factor. The method has broad applications for postproduction tuning of photonic devices.