Propagating and Evanescent TE-Polarized Bessel Light Beams in PT-Symmetric Systems

Parity-time (PT) symmetry offers a well-established route for enhancing light-matter interaction by means of formation of exceptional points. The model of plane waves is commonly used for finding and investigating exceptional points in open multilayer systems. Here we study behaviors of TE-polarized Bessel light beams in PT-symmetric multilayer structures. It is shown that, due to the translational invariance of the planar interfaces, the exceptional and diabolic points of the Bessel beam are identical to those of a conventional plane wave with the same angle of incidence. Basing on this equivalence, we adopt the method of scattering matrices to TE-polarized non-paraxial Bessel beams and determine positions of exceptional points depending on the transverse wave number and non-Hermiticity parameter for both propagating and evanescent beams. We reveal the evolution of exceptional and diabolic lines when the number of layers changes and find their link to the transmission and reflection spectra. This research may pave the way for exploiting light beams in non-Hermitian photonics.