Light localization in finite one-dimensional graphite-GaN heterostructures

The properties of light localization in finite one-dimensional photonic heterostructures composed of alternating layers of graphite and wurtzite GaN are studied theoretically. Results are obtained within the transfer-matrix formalism for both transversal-magnetic and transversal-electric polarizations of the incident electromagnetic wave in the infrared region of the electromagnetic spectrum. A structural disorder is introduced into the system by assuming that the width of the slabs in the heterostructure may randomly fluctuate around its mean value. For oblique incidence and transversal-magnetic polarization, a coupling of the infrared photon modes with the longitudinal optical phonons is discussed. This photon–phonon coupling gives rise to signatures of the phonon-polariton modes in the transmission and localization properties of the system, which are observed in the cases of low and moderate levels of structural disorder. The dependence of the properties of the light localization on the number of graphite-GaN double layers is also analyzed.