Open AccessStudy of different spectral regions and delay bandwidth relation in slow light photonic crystal waveguides
Author(s) -
Hamza Kurt,
Kadir Üstün,
Lokman Ayas
Publication year - 2010
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.18.026965
Subject(s) - optics , slow light , group velocity , bandwidth (computing) , photonic crystal , physics , refractive index , group delay and phase delay , dispersion relation , brillouin zone , figure of merit , group delay dispersion , telecommunications , optical fiber , fiber optic sensor , computer science , dispersion shifted fiber
We investigate slow light propagation in monomode photonic crystal waveguides with different spectral features such as constant group index, high bandwidth and low group velocity dispersion. The form of the waveguide mode alters dramatically and spans three different spectral intervals by tuning the size of the boundary holes. Namely, slope of the band gap guided mode changes sign from negative to positive toward the Brillouin zone edge. In between there is a transition region where modes have nearly zero slopes. Maximum group index occurs at these turning points at the expense of high dispersion and narrow bandwidth. The apparent trade-off relationship between group index and bandwidth is revealed systematically. We show that as the radius of the innermost hole is increased above a certain value, the former one decreases and the latter one increases both exponentially but with a different ratio. The product of average group index and bandwidth is defined as a figure of merit which reaches up to a value of approximately 0.30 after a detailed parametric search. The findings of the frequency domain analysis obtained by plane wave expansion method are confirmed via finite-difference time-domain study.