In contrast, the new materials are solid, stable films that are as clear as glass but whose molecules are also highly ordered, unlike normal glass. It's also easy to process using current technology. The materials are actually stacks of layers of molecules, each rotated slightly so that together the molecules form a clear spiral path for light to follow. Altogether the layers, which form themselves spontaneously into this rotational pattern, are anywhere from 4 to 35 microns thick, less than half the thickness of a human hair. When hit with unpolarized light from an ultraviolet source, the materials emit circularly polarized, color light.
Residual light is reflected and recycled, rather than absorbed and wasted as in current systems.
Most displays today use linear polarization, even though it's not as efficient as circular polarization, then use additional optical devices to produce color. We're hoping to make circular polarization an option for display technology. Besides brighter and more efficient displays, other applications of glassy liquid crystals include laser goggles that selectively filter out laser light at certain wavelengths, electro-optic devices for optical communication, and a new method to chemically convert explosives into useful display materials. Chen says the materials also have potential for optical storage, since at high temperatures they can switch states instantly in response to heat or light. Chen has been invited to discuss the findings as a plenary speaker at an international conference on novel optical materials and applications this summer in Italy.