Open AccessControl of radiation angle by introducing symmetric end structure to oblique waveguide in three-dimensional photonic crystal
Author(s) -
Kou Gondaira,
Kenji Ishizaki,
Keisuke Kitano,
Tanemasa Asano,
Susumu Noda
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.013518
Subject(s) - optics , waveguide , oblique case , radiation , photonic crystal , physics , total internal reflection , polar coordinate system , polar , optical axis , wavenumber , materials science , geometry , philosophy , linguistics , astronomy , lens (geology) , mathematics
We investigate the radiation angle of an oblique waveguide in a stripe-stacked three-dimensional photonic crystal. We show that the output-light is radiated in a different direction from the oblique waveguide direction. Moreover, the radiation polar angle varies from 30° to 50° depending on the frequency. To inhibit the frequency dependence and obtain vertical radiation, we introduced a symmetric structure at the end of the waveguide. As a result of cancellation of the in-plane asymmetric wavenumber, the radiation polar angle is less than 6° from the surface-normal direction and does not depend on frequency.