Christian Bohley, featured ILCC liquid crystal artist, November 2009

Cholesteric Phase of 55% CB15 (chiral dopant) in E48 (liquid crystal) in a sandwich cell observed between crossed polarizers. The blue areas are regions where the helical axis of the liquid crystal is in the viewing direction. There, a selective Bragg reflection takes place that is dependent on the liquid crystal properties and on the polarization of the incoming light. Interestingly, a strong reflection occurs if the light is circularly polarized and if the handedness of this polarization is of the same sense as the handedness of the cholesteric helix. The irregular areas are the so-called oily streaks, representing zones where the helices are deformed resp. rather perpendicular to the viewing direction. Oily streaks are typical for the beginning transition between cholesteric and isotropic phase.

Real width of the picture is about 3 x 2 mm.

Jury comment: a beautiful and perfectly photographed example of a classic liquid crystal texture. The colors are fantastic.
Christian Bohley graduated in Mathematics in 1991 at the University of Halle/Saale (Germany). In 2004 he obtained a PhD from the University of Neuchâtel (Switzerland). Then he worked at the University of Magdeburg (Germany) on nonlinear phenomena and since 2009 on optics of functional devices at the Institute of Physics at the Martin-Luther-University in Halle. His further research activities are in the mathematics of optics, optics of anisotropic media and self-organization phenomena in liquid crystals.