| Attributs | Valeurs |
|---|
| type
| |
| Is Part Of
| |
| Subject
| |
| Title
| - Phase-Type Gratings Formed by Photochemical Phase Transition of Polymer AzobenzeneLiquid Crystal. 2. Rapid Switching of Diffraction Beams in Thin Films
|
| has manifestation of work
| |
| related by
| |
| Author
| |
| Abstract
| - Dynamic holographic gratings were investigated with thin films of polymer azobenzene liquid crystals byperiodic induction of photochemical nematic-to-isotropic phase transition. On irradiation of writing beams(488 nm), multiple diffraction beams of a reading beam (633 nm) were immediately observed. The first-order diffraction efficiency reached to a maximum value within several tens of milliseconds: the rise timewas approximately 50 ms for PM6AB2 films and 30 ms for PA6ABCN films. Quite large modulation inrefractive index (∼0.08) was obtained in both polymer films. Studies on effects of temperature and lightintensity on the grating formation suggested that photochemical reactions of azobenzene moieties followedby photochemical phase transition in bright fringes of the interference pattern would be responsible for theformation of holographic gratings. By turning on and off the writing beams, the diffraction beams could beswitched dynamically without significant fatigue.
|
| article type
| |
| is part of this journal
| |
