1D randomized photonic crystals: influence as single- and dual-channel narrowband filter

Nowadays, optical filters with high-level performance are highly demanded. While examining the light transmission properties of both periodic and random one-dimensional (1D) photonic crystals, it is observed that random 1D photonic structures have more favorable properties to meet these demands. With the influence of randomness, novel single- and dual-channel narrowband filters at a 1550 nm wavelength for optical telecommunication are presented in this study. For designing narrowband filters, the central wavelength precision, quality factor and peak transmission are of great importance. Randomness can be attained by permuting the refractive indices of two dielectric materials through the binomial coefficient method, wherein the light transmission properties are calculated using the transfer matrix method. The proposed filters show a minimum full width at half maximum of 0.24 nm in the single-channel narrowband filter and 0.08 and 0.095 nm in the dual-channel narrowband filter at the chosen spectral region. This filters have ultra-narrowband transmission peaks compared with those of existing narrowband filters based on defective 1D photonic structures.