Optimization of wide-band quasi-omnidirectional 1-D photonic structures

We design, optimize, fabricate, and characterize highly reflective quasi-omnidirectional multilayered structures with a wide angular spectral range. consider chirped layers of gradually varying thicknesses made by stacking Bragg-type sub-structures, we maximized their numerically calculated reflectance averaged over different ranges keeping minimum thickness for given pairs refractive indices. fabricated some these porous silicon low contrast between adjacent layers, compared measured optical properties to the theoretical results previous works. obtained relatively thin mirrors bands wavelength that compare favorably others reported in literature.