Determination of guided-mode resonances in photonic crystal slabs

We present a design and analysis study of guided-mode resonances in photonic crystal slabs. Three-dimensional finite-difference time-domain (FDTD) simulations are used in parallel with a simplified model of guided-mode resonances to produce a representation of their evolution with structural parameters. From the analysis of the effective medium behavior of the system, we propose a simplified method able to predict the first guided-mode resonances at normal incidence with a good accuracy (similar to 1%) for holes with radius-to-period ratio smaller than 0.3 for the transverse magnetic polarization created internally. A substantial gain of time is, therefore, provided compared to FDTD (from the hours level to the seconds level). We also focus on two other important parameters, the quality factor and asymmetry of peaks, and present a way to design symmetric peaks with low sidebands. (C) 2011 Optical Society of America