Open AccessHyper collimation ability of two-dimensional photonic crystals
Author(s) -
Guangzhe Ru,
Yaxu Zheng,
Jiaxi Liu,
Xunya Jiang
Publication year - 2019
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.011968
Subject(s) - collimated light , optics , photonic crystal , flatness (cosmology) , dimensionless quantity , lattice (music) , physics , materials science , laser , acoustics , cosmology , quantum mechanics , mechanics
We theoretically investigate the collimation ability of photonic crystals (PhCs) and present a design of rectangular lattice PhC structure which has ultra-high collimation ability, referred to hyper collimation ability of PhC in this work. The competition between the range and the flatness of a "flat segment" on the PhC equi-frequency contour (EFC) is revealed, so that both should be considered simultaneously if we hope to evaluate the collimation ability of a PhC structure. We introduce a new dimensionless value, the normalized collimation length (NCL), to evaluate the collimation ability of a PhC structure. We find that the hyper collimation ability can be achieved by tuning the aspect ratio of a rectangular lattice PhC. It is also demonstrated that our theoretical predictions of the propagation behavior of beams agree very well with numerical experiments. We propose that the PhCs with hyper collimation ability could be widely used in the design of photonic circuits and other devices.