@article{6be032c201104f798ce8983371c6a278,
title = "Strongly Confining Light with Air-Mode Cavities in Inverse Rod-Connected Diamond Photonic Crystals",
abstract = "Three-dimensional dielectric optical crystals with a high index show a complete photonic bandgap (PBG), blocking light propagation in all directions. We show that this bandgap can be used to trap light in low-index defect cavities, leading to strongly enhanced local fields. We compute the band structure and optimize the bandgap of an inverse 3D rod-connected diamond (RCD) structure, using the plane-wave expansion (PWE) method. Selecting a structure with wide bandgap parameters, we then add air defects at the center of one of the high-index rods of the crystal and study the resulting cavity modes by exciting them with a broadband dipole source, using the finite-difference time-domain (FDTD) method. Various defect shapes were studied and showed extremely small normalized mode volumes (Veff) with long cavity storage times (quality factor Q). For an air-filled spherical cavity of radius 0.1 unit-cell, a record small-cavity mode volume of Veff~2.2 × 10−3 cubic wavelengths was obtained with Q~3.5 × 106. ",
keywords = "photonic bandgap materials, photonic crystals, microcavities",
author = "Mike Taverne and Ho, {Ying-Lung Daniel} and Rarity, {John G.}",
note = "Funding information: This research was funded by the Engineering and Physical Sciences Research Council (EPSRC), grant number EP/V040030/1, EP/M009033/1 and EP/M024458/1. ",
year = "2022",
month = feb,
day = "22",
doi = "10.3390/cryst12030303",
language = "English",
volume = "12",
journal = "Crystals",
issn = "2073-4352",
publisher = "MDPI AG",
number = "3",
}