Controllable finite ultra-narrow quality-factor peak in a perturbed Dirac-cone band structure of a photonic crystal slab

TL;DR

This paper demonstrates how a perturbed photonic Dirac-cone can produce ultra-narrow, tunable Q-factor peaks in wavevector space, enabling precise angular and frequency selection for optical devices.

Contribution

It introduces a method to realize and control finite ultra-narrow Q-factor peaks in photonic crystal slabs using Dirac-cone perturbations, with tunable peak value and width.

Findings

Achieved ultra-narrow, tunable Q-factor peaks in wavevector space.

Identified a lower bound for minimal peak width at given Q-value.

Demonstrated applications in optical devices requiring strong angle and frequency selection.

Abstract

We show that by using a perturbed photonic Dirac-cone, one can realize ultra-narrow and finite Q-factor peak in the wavevector space, with both the peak value and the width separately tunable. We also discuss a lower bound in the minimal viable width given a peak Q-value while maintaining sufficient Q differentiation among modes. The strong angular and frequency Q-selection finds applications in optical devices where strong angle- and frequency-selection is needed.