As part of an international research team, scientists at Siberian Federal University (SibFU) have extended the life of a special state of light that arises at the interface between a cholesteric liquid crystal and a layered medium. This will help create devices for taking medical tests at home. The study results were published in Crystals magazine.
The optical state studied by the research team is localised light that forms at the interface between two media playing the role of mirrors. Due to multiple re-reflections, the light turns out to be “trapped” and “blocked” at the interface. When light falls at the interface between the media, reflected and refracted rays appear.
When there is a limiting angle of total reflection, a beam can appear that glides along with the interface — a surface light wave.
Using the cholesteric liquid crystal, the scientists have managed to spin the stopped light like a whirligig toy. This liquid crystal doesn’t have mirror symmetry, since it consists of oriented oblong molecules, the direction of which is twisted into a spiral, like a spiral staircase.
The resulting “light top” lives longer than ordinary waves. The scientists called it the chiral optical Tamm state.
The research team also included scientists from Kirensky Institute of Physics, Federal Research Center KSC SB RAS and National Chiao Tung University (Taiwan).
The study results were published in Crystals magazine.