The diffraction characteristics of a dual-periodicity superlattice-a diffraction grating whose unit cell contains two different regions, one homogeneous and the other periodically nonhomogeneous-were numerically simulated. After choosing the second region to have sinusoidally varying permittivity, the widely used rigorous coupled-wave approach was applied to compute the reflection and transmission efficiency spectrums. An extensive parametric study revealed that the dual-periodicity superlattice exhibits anomalies in the long-wavelength regime which can be considered to be resonance anomalies (RAs), which are distinct from the Rayleigh-Wood anomalies. Also, double-periodicity superlattices exhibit RAs at higher wavelengths than single-periodicity superlattices.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering