Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5442634 | Optical Materials | 2017 | 6 Pages |
Abstract
In this paper, we have experimentally investigated polarization properties of the blue phase of a cholesteric liquid crystal in polycrystalline cells with different alignment layers. Experiments were carried out by various temperatures and wavelengths within the spectral range covering Bragg reflection. It was conclusively demonstrated that the change of polarization state of transmitted light through polycrystalline BP-cell is mainly due to Bragg reflection, while optical activity is relatively small. Besides, the linear birefringence was not observed, as expected. It was shown that the ellipticity of the outgoing polarization state can change from almost linear (1.33%) to elliptic (7.33%), depending on sample orientation, with negligible changing of optical rotatory power (for BP I at 470Â nm). The results indicate that also polycrystalline BPLC structure, although locally anisotropic, is macroscopically isotropic showing non-negligible optical activity only for resonant wavelengths, although being much lower than that in a typical cholesteric phase. It was also shown that different alignment layers in BP-cell may shift Bragg reflection spectral range, so influencing the outgoing polarization state for particular wavelength.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Kamil Orzechowski, Marek W. Sierakowski, Marzena Sala-Tefelska, Pankaj Joshi, Tomasz R. WoliÅski, Herbert De Smet,