Photonic band gap structures based on periodically grooved silicon

Using wet anisotropic etching of [110] Si a number of periodically grooved Si structures with lattice constant, A, ranging from 3 to 16 μm have been designed and fabricated. A number of structures with different type of "defects" have also been designed and fabricated. These structures with high contrast in refractive index (n_si/n_air = 3.42/1) not only possess a wide main band gap for the photons, but also have reasonably wide secondary stop bands at shorter wavelengths. The IR reflectance spectra for such structures simulated using the method of characteristic matrix showed good agreement with the experimental data. Based on these calculations a "gap map" was produced for periodically grooved Si acting as a 1D photonic crystal.