Omnidirectional photonic bangap in dielectric mirrors: a comparative study

We report the theoretical comparison of the omnidirectional photonic band gap (OPBG) of one-dimensional dielectric photonic structures, using three different refractive index profiles: sinusoidal, Gaussian and Bragg. For different values of optical thickness, the tunability of the OPBG of each profile is shown to depend on the maximum, minimum and the difference of the refractive indices. An experimental verification was carried out with a multilayered dielectric porous silicon structure for all the three profiles. The optimal combination of refractive indices for each structure which generates the maximum OPBG has also been calculated. Such study can be useful to design the required OPBG structures for photonic applications.