Ultra-high-Q UV microring resonators based on single-crystalline AlN platform

TL;DR

This paper reports the development of ultra-high-Q ultraviolet microring resonators using single-crystalline aluminum nitride, achieving record quality factors and enabling advanced UV photonic applications.

Contribution

Demonstration of a record quality factor of 2.1 x 10^5 in AlN microrings at 390 nm, advancing UV photonic integrated circuits.

Findings

Record quality factor of 2.1 x 10^5 at 390 nm

Low optical loss of approximately 8 dB/cm

Compatibility with UV emitters and quantum photonic applications

Abstract

Development of low-loss photonic components in the ultraviolet (UV) band will open new prospects for classical and quantum optics. Compared with other integrated platforms, aluminum nitride (AlN) is particularly attractive as it features an enormous bandgap of ~6.2 eV and intrinsic chi(2) and chi(3) susceptibilities. In this work, we demonstrate a record quality factor of 2.1 x 105 (optical loss ~ 8 dB/cm) at 390 nm based on single-crystalline AlN microrings. The low-loss AlN UV waveguide represents a significant milestone toward UV photonic integrated circuits as it features full compatibility for future incorporation of AlGaN-based UV emitters and receivers. On-chip UV spectroscopy, nonlinear optics and quantum information processing can also be envisioned.