Liquid Crystal Lasers Could be Mass-Printed to Create ‘Smart’ Materials_Featured_, Technology Monday, September 24th, 2012
(Wired) A team of physicists has published a study detailing how it has devised a cheap way to print lasers on to nearly any surface using an ordinary inkjet printer — a find that could revolutionise the future production and use of lasers.
The paper, published in the journal Soft Matter, explains how a team of University of Cambridge physicists and engineers printed hundreds of small dots of chiral nematic liquid crystal molecules (LC) — which are already used to create organic lasers — on to a material coated with a wet polymer solution. When that solution dries, it reacts with the liquid crystals, causing them to align and be transformed into individual multi-colour lasers, without the addition of mirrors.
Normally, physicists align LCs to create lasers by carefully placing the molecules between two tiny glass plates, covered with a polymer coating and spaced apart to allow the reflection of light. By aligning the molecules, the LC becomes an optically resonant cavity — an array that directs pure light. The process is a costly and time-consuming one, and really allows for the lasers to only be created on glass or silicon. The process being proposed by the University of Cambridge is not only far more cost-effective, but could totally change the way we use lasers since it allows them to be produced on any surface imaginable. Without the need for mirrors (the molecules are aligned solely using the polymer solution) the team suggests that ordinary printing presses could even be converted to mass-produce the effect for things like “smart wallpaper”.
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