The effect of interfacial roughness on the normal incidence bandgap of one-dimensional photonic crystals

TitleThe effect of interfacial roughness on the normal incidence bandgap of one-dimensional photonic crystals
Publication TypeJournal Article
Year of Publication2005
AuthorsMaskaly, KR, Carter, WCraig, Averitt, RD, Maxwell, JL
JournalOptics Express
Volume13
Issue21
Pagination8380 - 8389
Date Published2005/10/17/
Abstract

As discussed previously, interfacial roughness in one-dimensional photonic crystals (1DPCs) can have a significant effect on their normal reflectivity at the quarter-wave tuned wavelength. We report additional finite-difference time-domain (FDTD) simulations that reveal the effect of interfacial roughness on the normal-incidence reflectivity at several other wavelengths within the photonic bandgaps of various 1DPC quarter-wave stacks. The results predict that both a narrowing and red-shifting of the bandgaps will occur due to the roughness features. These FDTD results are compared to results obtained when the homogenization approximation is applied to the same structures. The homogenization approximation reproduces the FDTD results, revealing that this approximation is applicable to roughened 1DPCs within the parameter range tested (rms roughnesses < 20% and rms wavelengths < 50% of the photonic crystal periodicity) across the entire normal incidence bandgap. (c) 2005 Optical Society of America.