JungHyun Noh, Irena Drevensek-Olenik, Jun Yamamoto, and Jan P. F. Lagerwall, “Dynamic and complex optical patterns from colloids of cholesteric liquid crystal droplets,” Emerging Liquid Crystal Technologies X, Liang-Chy Chien, Harry J. Coles, Hirotsugu Kikuchi, Ivan I. Smalyukh, Editors, Proc. SPIE 9384, 93840T (2015). Copyright 2015 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
All documents in ORBilu are protected by a user license.
[en] Drops or shells of a planar-aligned short-pitch cholesteric liquid crystal exhibit unique optical properties due to the combination of Bragg reflection in the cholesteric helix and a radial orientation of the helix axis. If such a droplet is illuminated from above, light is reflected into a continuous set of cones, the opening angles of which depend on where on the droplet the light hits its surface. For the wavelength that fulfills the Bragg condition the reflection is dramatically enhanced, yielding the light cones colored. A photonic cross communication scheme arises for certain angles, reflecting light back to the observer from a different droplet than the one originally illuminated. This gives rise to an intricate pattern of colored and circularly polarized spots. A number of interesting applications may be developed based on this pattern, e.g. in identification and authentication devices. We have carried out a detailed spectrophotometric analysis of the patterns, localized to individual spot maxima. A quantitative comparison between the measured spectra and the reflection wavelength expected from a model for the pattern generation allows us to conclude that the droplets are in fact not spherical but slightly ellipsoidal.
Disciplines :
Materials science & engineering
Author, co-author :
Noh, Junghyun ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Drevensek-Olenik, Irena; University of Ljubljana > Faculty of Mathematics & Physics
Yamamoto, Jun; Kyoto University > Department of Physics
Lagerwall, Jan ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
External co-authors :
yes
Language :
English
Title :
Dynamic and complex optical patterns from colloids of cholesteric liquid crystal droplets
Publication date :
2015
Event name :
SPIE Opto
Event organizer :
SPIE
Event place :
San Francisco, United States
Event date :
February 7-12, 2015
By request :
Yes
Audience :
International
Journal title :
Proceedings of the SPIE
eISSN :
1996-756X
Publisher :
Bellingham, Wash. : The International Society of optical engineering.