Abstract
We have studied both theoretically and experimentally an omnidirectional reflector operating at the wavelength region of 1.3 $\mu$m. The omnnidirectional reflector, a special case of one-dimensional photonic crystals, was prepared by alternately sputtering two dielectric materials, amorphous silicon and silicon dioxide. Measured reflectance spectra, very consistent with simulated results at all angles and polarizations, clearly showed the existence of an omnidirectional photonic bandgap.