From Event: SPIE Organic Photonics + Electronics, 2017
By illuminating a photo-alignment layer with two interfering UV laser beams with opposite circular polarization, a periodic alignment pattern is obtained for nematic liquid crystal. In a liquid crystal cell two substrates are used with periodic photo-alignment, with the periodicities perpendicular to each other. After filling with nematic liquid crystal the director obtains a 3D pattern with period twice that of the photo-alignment. The resulting 3D structure depends on the cell thickness (between 3 and 20 m) and the periodicity of the photo-alignment (also between 3 and 20 m). The director pattern can be estimated by performing numerical simulation with a Q-tensor method. The simulation results can be verified by polarization optical microscopy or by observing the diffraction properties of the structure. For a long range periodicity combined with a small period, the light is efficiently distributed over a small number of diffraction orders. The director pattern can be reoriented by applying a potential difference between the two substrate electrodes. Optical and electrical steering is investigated for devices with different dimensions.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the conference proceedings. They include the speaker's narration along with a video recording of the presentation slides and animations. Many conference presentations also include full-text papers. Search and browse our growing collection of more than 14,000 conference presentations, including many plenary and keynote presentations.
Study of self-shadowing effect as a simple means to realize nanostructured thin films and layers with special attentions to birefringent obliquely deposited thin films and photo-luminescent porous silicon