20.500.12556/RUL-174870 Focused beam propagation in cholesteric liquid crystals In this paper, we develop a numerical technique that allows us to study the propagation of tightly focused scalar or vector beams through a stratified birefringent material. The technique is based on the Berreman 4 × 4 transfer matrix method and modal decomposition using the Fourier transform. Instead of the usual Berreman vector, describing the electric and magnetic field components, we introduce a novel concept and represent the field vector components using a generalized bi-directional Jones vector. The Jones vector formulation simplifies the creation of focused beams and allows studying the beams’ polarization state, intensity, and propagation direction using the usual 2 × 2 Jones matrix formalism. We develop a numerical model for an ideal high numerical aperture lens transform, and we use the technique to focus a tilted beam and propagate the beam through the cholesteric liquid crystal. Compared to plane waves at normal incidence, the transmission spectra of focused beams start to differ when the beam’s Rayleigh length becomes comparable to the cholesteric thickness. The bandgap of the cholesteric liquid crystal remains unchanged, but we observe a reduced transmission in the side lobes near the edge of the bandgap. The effect is significantly enhanced when propagation is at oblique incidence with respect to the helical axis and for tightly focused beams, where the resonances near the bandgap disappear. cholesteric liquid crystals optics holesterični tekoči kristali optika true false true Angleški jezik Slovenski jezik Članek v reviji 2025-10-10 11:46:56 2025-10-10 11:46:56 2025-12-01 03:52:07 0000-00-00 00:00:00 2025 0 0 Str. 32955-32975 iss. 16 Vol. 33 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 535:538.9 1094-4087 10.1364/OE.565420 252679427 oe-33-16-32955.pdf oe-33-16-32955.pdf 1 E3771CE5A6AC6179A7B1591FF6AE3F22 e563830433acd9da7663b91c31b74058141c1fb78c9872e42afa3a6ab56b1852 f257e531-a5bd-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=219775 https://opg.optica.org/oe/fulltext.cfm?uri=oe-33-16-32955 0 0165c6f8-a5be-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=219776 Fakulteta za matematiko in fiziko 0 0 0