Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 15: Poster: New Instruments and Methods

CPP 15.18: Poster

Dienstag, 27. März 2012, 18:15–20:15, Poster A

Improving the performance of liquid crystal lasers by electric fields — •Jürgen Schmidtke, Lu Lu, and Heinz-Siegfried Kitzerow — Department Chemie, Universität Paderborn, Germany

During the past decade, self-assembled photonic band edge lasers based on dye-doped cholesteric liquid crystals have attracted considerable interest as tunable, miniature light sources. We demonstrate that the lasing threshold and slope efficiency of a liquid crystal laser can be improved by application of an electric field: Using a dye-doped cholesteric liquid crystal with negative dielectric anisotropy as the DFB laser structure, emission characteristics improves with increasing ac electric field along the cholesteric helix. Possible reasons are a partial suppression of thermally driven director fluctuations, as well as a stabilization of the planar cholesteric texture against disturbances by the optical pumping process.