High-Q aluminum nitride photonic crystal nanobeam cavities

TL;DR

This paper reports the fabrication and characterization of aluminum nitride photonic crystal nanobeam cavities with high optical quality factors, enabling advanced integrated photonic devices using a low-loss, nonlinear material.

Contribution

Demonstrates high-Q AlN nanobeam cavities fabricated with a novel self-protecting release process, achieving quality factors up to 146,000 and high extinction ratios.

Findings

Quality factors up to 146,000 achieved

Extinction ratios over 15 dB demonstrated

Potential for integrated nonlinear photonic devices

Abstract

We demonstrate high optical quality factors in aluminum nitride (AlN) photonic crystal nanobeam cavities. Suspended AlN photonic crystal nanobeams are fabricated in sputter-deposited AlN-on-insulator substrates using a self-protecting release process. Employing one-dimensional photonic crystal cavities coupled to integrated optical circuits we measure quality factors up to 146,000. By varying the waveguide-cavity coupling gap, extinction ratios in excess of 15 dB are obtained. Our results open the door for integrated photonic bandgap structures made from a low loss, wide-transparency, nonlinear optical material system.