Researchers Invent Ultra-Small Nanoscale Optical Switch
20 March 2014
A team of researchers has developed a new ultra-small optical device that can switch on and off trillions of times a second, potentially bringing closer the day when photons will take the place of electrons in consumer products.
This ultra-fast optical switch was created by scientists from Vanderbilt University, University of Alabama-Birmingham and Los Alamos National Laboratory. The device was made out of “metamaterial” and consists of individual switches with a diameter of 200 nanometers, or one five-hundredth of the width of a human hair.
The device is much smaller than conventional optical switches and was assembled out of nanoscale particles of vanadium dioxide (VO2), which are deposited on a glass substrate and coated with a “nanomesh” of small gold nanoparticles. By targeting these nanoparticles with brief pulses from an ultra-fast laser, the scientists enabled the generation of hot electrons in the gold nanomesh that spring into the vanadium dioxide, thus triggering its phase change within a period lasting a few trillionths of a second.
The integration of optics into electronics is an area currently seeing significant investment by both industry and government, given the potential of optics to bring information and communications technology to the next level. In the last five years a number of companies have been focusing on the creation of chips with increasing optical functionalities that perform at gigahertz speeds, or a thousandth that of the vanadium dioxide switch. According to the researchers, the novel device has the potential to overcome one of the major technical limitations to the spread of electronic devices that detect and control light by making the process of miniaturization of ultra-fast optical switches possible.