Photonic passbands induced by optical fractal effect in Cantor dielectric multilayers

Abstract

We investigate the splitting and incorporation of optical fractal states in one-dimensional photonic quasi-crystals. The aperiodic crystals which are composed of two different dielectrics submit to Cantor sequence. Defects in Cantor crystals can greatly enhance the localization of electric field, which induces the optical fractal effect. The number of optical fractal states increases exponentially with the generation number of Cantor sequence. Moreover, the optical fractal characteristics depend on the incident angle of light, of which the fractal states may split/incorporate by modulating the value of incident angle. This study could be utilized for band-pass filters and reflectors.

Photonic Band Gap and Fractal Resonances in Aperiodic Cantor-like Self-Similar a:SiNx Photonic Structures

“…The exponential growth of the constituent number of layers (3 N ) generally hinders the fabrication of more than N=2 cantor sequences with accuracy and precision as desired. 41 Considering the ease of fabrication and experimental realization of the aperiodic structures, we focus on the cantor tripartite (N = 2) structures consisting of 9 layers (as depicted in Figure 1), exhibiting a pronounced transmission resonance cavity mode in the visible region. Owing to its wide tunability in the refractive index and band gap a:SiN x along with a change in its stoichiometry, it has been used as a constituting layer for the fabrication of the photonic structures.…”

“…Spectral behavior of ACPQ structures of N = 2 by varying the constituent layer thicknesses (λ/ n to λ/20 n , n is the refractive index) has been demonstrated using TMM simulations (Supporting Figure S3). The exponential growth of the constituent number of layers (3 N ) generally hinders the fabrication of more than N=2 cantor sequences with accuracy and precision as desired …”