Laser light can switch a vanadium oxide film between reflective and transparent states without heating or cooling, according to recent research by Vanderbilt University and the teams of Alfred Leitenstorfer of Konstanz University in Germany and Richard Haglund at Vanderbilt University, New York. It is one of the few examples of light being used to induce a direct physical transition without changing a material's temperature. Such "coherent control" has been used previously to control photosynthesis and is being investigated in quantum bit, qubit, research. The work could represent the first step towards a new generation of ultra-fast optical switches for telecommunications.
An Optical Open and Shut Case