Diffraction inspired unidirectional and bidirectional beam splitting in defect-containing photonic structures without interface corrugations
Date
2016Source Title
Journal of Applied Physics
Print ISSN
0021-8979
Publisher
American Institute of Physics Inc.
Volume
119
Issue
19
Pages
10 - 1
Language
English
Type
ArticleItem Usage Stats
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Abstract
It is shown that strong diffractions and related dual-beam splitting can be obtained at transmission through the nonsymmetric structures that represent two slabs of photonic crystal (PhC) separated by a single coupled-cavity type defect layer, while there are no grating-like corrugations at the interfaces. The basic operation regimes include unidirectional and bidirectional splitting that occur due to the dominant contribution of the first positive and first negative diffraction orders to the transmission, which is typically connected with different manifestations of the asymmetric transmission phenomenon. Being the main component of the resulting transmission mechanism, diffractions appear owing to the effect exerted by the defect layer that works like an embedded diffractive element. Two mechanisms can co-exist in one structure, which differ, among others, in that whether dispersion allows coupling of zero order to a wave propagating in the regular, i.e., defect-free PhC segments or not. The possibility of strong diffractions and efficient splitting related to it strongly depend on the dispersion properties of the Floquet-Bloch modes of the PhC. Existence of one of the studied transmission scenarios is not affected by location of the defect layer.
Keywords
DiffractionDispersion (waves)
Asymmetric transmissions
Diffraction orders
Diffractive element
Dispersion properties
Dominant contributions
Floquet-Bloch mode
Photonic structure
Transmission mechanisms
Defects