Cherenkov radiation in liquid crystals
Abstract
The up-to-date state of investigations of charged particle coherent radiation in liquid crystals is presented with most attention being paid to coherent radiation in chiral liquid crystals. A detailed analysis of Cherenkov radiation and "structure Cherenkov" radiation in cholesteric liquid crystals is given. It is shown that there are essential differences in the characteristics of Cherenkov radiation in cholesterics compared to Cherenkov radiation in homogeneous media. These reveal themselves in the spectral and angular distributions of the radiation and in its polarization properties. Many of these, in particular the two cones of emission, the divergence of the differential with respect to frequency (or angle) of the emission intensity and the shift of the threshold velocity for Cherenkov radiation, are common to Cherenkov radiation in any periodic medium. The prospects for experimental observation of the examined Cherenkov radiation peculiarities in chiral liquid crystals are briefly discussed, and the significance of the relevant measurements for studying coherent radiation from charged particles in other periodic media and other frequency ranges are noted.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- July 1986
- DOI:
- 10.1016/0168-9002(86)90492-4
- Bibcode:
- 1986NIMPA.248...20B