Localization and polarization transformation of waves by an asymmetrical modified Fibonacci chiral multilayer

Dispersion blue-shift in an aperiodic Bragg reflection waveguide

“…the width and position of stopbands on the frequency scale, which are key characteristics that are taken into consideration when designing the Bragg reflection waveguides. As noted in our previous papers [18,19,20,21], stopbands in the spectra of aperiodic structures can appear to be shifted in comparison with the stopbands in the spectra of periodic structures assuming the same material parameters and number of layers in the multilayered systems. Therefore, in this paper, in order to provide a comparative study, we consider spectral features and dispersion characteristics of a Bragg reflection waveguide having either periodic or aperiodic configuration of layers in the cladding.…”

“…Here n j takes on values n g for the core layer, and n and n Υ for the Ψ and Υ cladding layers, respectively. The field amplitudes for the structure input and output are evaluated as [18,19,20]…”

“…is the transverse wavenumber in the core, n ef f = β/k 0 is introduced as an effective refractive index for each particular guided mode, k 0 = ω/c is the free space wavenumber, and R is the complex reflection coefficient of the Bragg mirror which is depended on the wave polarization. The reflection coefficient R can be derived engaging the transfer matrix formalism [18,19,20] (see, Appendix B).…”