Eur. Phys. J. E (2007) 24: 297-302
https://doi.org/10.1140/epje/i2007-10239-7

Regular Article

Angular tuning of defect modes spectrum in the one-dimensional photonic crystal with liquid-crystal layer

¹ L.V. Kirensky Institute of Physics, Krasnoyarsk Scientific Centre, SB RAS, 660036, Krasnoyarsk, Russia
² Siberian Federal University, 660041, Krasnoyarsk, Russia

^* e-mail: gun@iph.krasn.ru

Received: 12 July 2007
Accepted: 5 November 2007
Published online: 5 December 2007

Abstract

A one-dimensional ZrO₂/SiO₂ photonic crystal with a 4-n -pentyl-4' -cyanobiphenyl (5CB) nematic defect layer was used to investigate the transmission spectra of light polarized parallel and perpendicular to the liquid-crystal director at different angles of incidence. The spectra of the photonic crystal were shown to split into four polarized components T_ij at oblique incidence. When the incident angle increased, the bandgap edges and the defect modes shifted towards short wavelengths, while the amplitudes of the defect modes increased for the transverse magnetic polarization and decreased for the transverse electric polarization. The observed discrepancy between the defect mode amplitudes in the center and near the edges of the photonic bandgap was found to be related to the radiation losses inside the defect layer of a non-ideal photonic crystal. The simulated transmission spectra obtained using recurrence relations and taking into account the decay of defect modes are in good agreement with the experimental data.