| 摘要 |
Electrooptic devices (100, 600, 700) include a left handed (102, 708) and right handed (104, 710) cholesteric phase liquid crystal layers. Electrodes (120, 122, 124, 126, 602, 604) or magnetic coils (704, 706) are used to apply electric or magnetic fields perpendicular to helical axes of the cholesteric phase liquid crystal layers. The fields lengthen the helical pitch of the liquid crystal layers thereby shifting the reflectance of the liquid crystal layers to longer wavelengths. Spectral reflectance of both left and right hand polarized light is controlled by the electrooptic devices. |
