Exploiting long-range disorder in slow-light photonic crystal waveguides

TL;DR

This paper demonstrates that introducing long-range correlated disorder in photonic crystal waveguides can significantly enhance light localization and quality factors, opening new avenues for optical device applications.

Contribution

It provides a rigorous analysis of how long-range correlations reduce radiative losses and increase cavity quality factors in photonic crystal waveguides, a novel approach in disorder engineering.

Findings

Long-range correlated disorder enhances cavity Q factors.

Inter-hole correlations reduce radiative losses.

Increased intensity fluctuations with correlation length.

Abstract

The interplay between order and disorder in photonic lattices opens up a wide range of novel optical scattering mechanisms, resonances, and applications that can be obscured by typical ordered design approaches to photonics. Striking examples include Anderson localization, random lasers, and visible light scattering in biophotonic structures such as butterfly wings. In this work, we present a profound example of light localization in photonic crystal waveguides by introducing long-range correlated disorder. Using a rigorous three-dimensional Bloch mode expansion technique, we demonstrate how inter-hole correlations have a negative contribution to the total out-of-plane radiative losses, leading to a pronounced enhancement of the quality factor, $Q$, and $Q/V$ cavity figures of merit in the long-range correlation regime. Subsequently, the intensity fluctuations of the system are shown to globally increase with the correlation length, highlighting the non-trivial role of long-range disorder on the underlying scattering mechanisms. We also explore the possibility of creating ultra-high quality cavity modes via inter-hole correlations, which have various functionalities in chip-based nonlinear optics and waveguide cavity-quantum electrodynamics.