Dispersion blue-shift in an aperiodic Bragg reflection waveguide

Abstract

A particular feature of an aperiodic design of cladding of Bragg reflection waveguides to demonstrate a dispersion blue-shift is elucidated. It is made on the basis of a comparative study of dispersion characteristics of both periodic and aperiodic configurations of Bragg mirrors in the waveguide system, wherein for the aperiodic configuration three procedures for layers alternating, namely Fibonacci, Thue-Morse and Kolakoski substitutional rules are considered. It was found out that, in a Bragg reflection waveguide with any considered aperiodic cladding, dispersion curves of guided modes appear to be shifted to shorter wavelengths compared to the periodic configuration regardless of the modes polarization.

Dispersion properties of Kolakoski-cladding hollow-core nanophotonic Bragg waveguide

“…Remarkably, even in the case when constitutive materials of layers in the core and cladding are considered to be without intrinsic losses, for a finite number of these layers N in the multilayered system, solutions of dispersion equation (11) appear in the field of complex numbers β because there is an inevitable energy leakage through the outermost layers. Thus, the resulting propagation constant is sought in the complex form as β = β ′ + iβ ′′ .…”

“…Such photonic bandgap guidance brings several attractive features to the waveguide characteristics [8], in particular, because most of light is guided inside a lowindex core (which can even be an air channel), losses and nonlinear effects can be significantly suppressed. Moreover, the mode area, mode profile, and dispersion properties of Bragg reflection waveguides can be optimized by providing specific choice of constituents and cladding configuration (e.g., by utilization of chirping [9] or aperiodic [10,11] designs for the Bragg mirrors). The interest to the mentioned unique features of Bragg reflection waveguides arises sufficiently in recent years because of the advances in the deposition and crystal growth technologies, which made possible the fabrication of waveguides with complicate designs assuring an appropriate quality.…”

Complex waveguide based on a magneto-optic layer and a dielectric photonic crystal

“…[4]. The aperiodic Bragg reflection waveguides have been also investigated to demonstrate a dispersion blue-shift [8]. Effects of linear chirp either in thickness or in refractive index of the cladding layers on the propagation characteristics of one-dimensional photonic band gap planar Bragg reflection waveguides are reported in [16].…”