Department of Nuclear and Atomic Physics Seminars
Distributed Feedback Lasers from Cholesteric Liquid Crystals
by Dr. Arun Kumar T. (University of Hyderabad)
Friday, November 30, 2012
from
to
(Asia/Kolkata)
at Colaba Campus ( P305 )
at Colaba Campus ( P305 )
Description |
We considered a negative dielectric anisotropic nematic liquid crystal (CCN-47) in a Perfluoropolymer (CYTOP) treated liquid crystal cell which shows discontinuous anchoring transition (Orientational Transition) from planar to homeotropic state. Cholesteric liquid crystals (CLCs) which are prepared from CCN-47 and some chiral agents also shows anchoring transition from fan shape to finger print texture and finger print to homeotropic state. This means that the helix of CLCs changes from normal to tangential. The helix switching between normal and tangential to the surface may provide new applications. For instance, tuning of beam direction in dye-doped CLC lasers becomes possible. Moreover, continuous tuning of wavelength by external stimuli is possible, if the molecules are released from strongly anchored surfaces. |
Organised by | Dr. Vaibhav Prabhudesai |