10.1007/s11447-008-2017-9

Abstract

Transmission spectra of a one-dimensional photonic crystal (PC) formed by two multilayer dielectric mirrors and a planar oriented layer of 5CB nematic liquid crystal (LC) that is sandwiched between these mirrors and serves as a structure defect are investigated experimentally. Specific features of the behavior of the spectrum of defect modes as a function of the angle of incidence of light on the crystal are studied for two polarizations: parallel and perpendicular to the director of the LC; the director either lies in the plane of incidence or is perpendicular to it. It is shown that, for the configurations considered, the maxima of the defect modes shift toward the short-wavelength region as the tilt angle of incidence radiation increases; this tendency is more manifest for the parallel-polarized component, when the director lies in the plane of incidence. In the latter case, the width of the photonic band gap (PBG) appreciably decreases. The temperature dependence of the polarization components of the transmission spectra of a PC is investigated in the case of normal incidence of light. The spectral shift of defect modes due to the variation of the refractive index of the LC at the nematic-isotropic liquid phase transition point is measured. It is shown that, in real PCs, the amplitude of defect modes decreases when approaching the center of the band gap, as well as when the number of layers in the dielectric mirrors increases. Theoretical transmission spectra of the PCs calculated by the method of recurrence relations with regard to the decay of defect modes are in good agreement with experimental data.

Polarization exchange of optical eigenmode pair in twisted-nematic Fabry-Pérot resonator

“…The Fabry-Pérot resonator includes two identical dielectric mirrors, each consisting of six 55nm-thick zirconium dioxide (ZrO 2 ) layers with a refractive index of 2.04 and five 102-nm-thick silicon dioxide (SiO 2 ) layers with a refractive index of 1.45 alternatively deposited onto a fused quartz substrate. The alternating ZrO 2 /SiO 2 layers produce a spectral reflection band, which is the stop-band, in the spectral range of 425-625 nm [15]. Thin indium tin oxide (ITO) electrodes preliminary deposited onto quartz substrates served to apply the voltage along the mirror surface normal.…”

Tunable hybrid Tamm-microcavity states

“…In the figure, one can see the motion of peaks corresponding to the hybrid modes. Since the bare TPP wevelength remains invariable, the motion of peaks can be explained by the sensitivity of the MC mode wevelengths to the applied temperature field 31 . As the temperature increases, the refractive index n e decreases, which leads to a decrease in the MC optical thickness and, consequently, to the blue shift of MC modes ( Fig.…”

“…The possibility of controlling MC modes in a 1D PC containing the nematic as a defect was demonstrated in [31][32][33] The MC modes were controlled using temperature, electric, and magnetic fields applied to the defect layer and by changing the angle of incidence and polarization of light.…”