Integrated optics Bragg grating ring resonators with Q-factor on gigascale

TL;DR

This paper proposes a novel optical ring resonator design using a long period Bragg grating to achieve ultra-high Q-factors exceeding 10^9, promising significant advancements in physics and engineering applications.

Contribution

The paper introduces a new design for optical ring resonators that leverages band-edge resonances in Bragg gratings to significantly increase the Q-factor beyond conventional limits.

Findings

Q-factor higher than 10^9 demonstrated theoretically

Q-factor enhancement scales with the square of the number of grating periods

Numerical results show an order of magnitude improvement over traditional resonators

Abstract

In this paper we propose a new optical ring resonator with a very high Q-factor, to be used as a basic element in a wide range of physics and engineering applications. We theoretically demonstrate that in large size conventional ring resonators, a value of the Q-factor higher than 109 is achievable by exploiting the band-edge resonances in a waveguiding long period Bragg grating closed loop, excited through a bus waveguide. The dispersion introduced by the Bragg grating is responsible for a reduction in the band edge resonance linewidth, which is inversely proportional to the square of the number of periods of the grating, thus allowing the overall Q-factor to be enhanced. Numerical results show a substantial improvement in the Q-factor, giving a number of order of magnitude higher than that of a conventional large size ring resonator.