High Q micro-ring resonators fabricated from polycrystalline aluminum nitride films for near infrared and visible photonics

TL;DR

This paper demonstrates high-Q micro-ring resonators made from sputter-deposited aluminum nitride films, achieving low loss and high-quality factors across near-infrared and visible wavelengths for integrated photonics.

Contribution

It introduces a fabrication process for aluminum nitride micro-ring resonators with record-high quality factors in both near-infrared and visible spectra.

Findings

Achieved Q factor of 440,000 in the telecom C-band

Demonstrated intrinsic Q factors over 30,000 at 770 nm

Realized critical coupling with extinction ratios above 30 dB

Abstract

We demonstrate wideband integrated photonic circuits in sputter-deposited aluminum nitride (AlN) thin films. At both near-infrared and visible wavelengths, we achieve low propagation loss in integrated waveguides and realize high-quality optical resonators. In the telecoms C-band (1520-1580 nm), we obtain the highest optical Q factor of 440,000. Critical coupled devices show extinction ratio above 30 dB. For visible wavelengths (around 770 nm), intrinsic quality factors in excess of 30,000 is demonstrated. Our work illustrates the potential of AlN as a low loss material for wideband optical applications.