Researchers from the University of Minnesota have developed a chip on which both sound wave and light wave are generated and confined together so that the sound can efficiently control the light. The chip consists of a silicon base coated with a layer of aluminum nitride. Applying alternating electrical signal to the system causes the material to deform periodically and generate sound waves that grow on its surface. The technology has been widely used in cell phones and other wireless devices as microwave filters. The novelty is to integrate optical circuits in the same layer of material with the acoustic device in order to attain strong interaction between light and sound waves. In the chip, arrays of electrodes have a width of about 100 nanometers, which means it generates sound waves at a frequency that is higher than 10 GHz. The platform could improve wireless communications systems using optical fibers and be used for quantum computation. For quantum applications, the researchers are investigating the interaction between single photons and single phonons. They plan to use sound waves as the information carriers in quantum computing.
Source: University of Minnesota