Optically switched transistor developed by research team
1 min read
Researchers at the Ecole Polytechnique Fédérale de Lausanne and the Max Planck Institute of Quantum Optics have discovered a way to switch light optically on a chip using the interaction of photons with phonons, or mechanical vibrations.
The development allows the transmission of a light beam past a chip based optical microresonator to be controlled directly by a second, stronger, light beam. The device could have applications in telecommunication and quantum information applications.
While a similar effect – electromagnetically induced transparency – has been observed through the interaction of laser light with atomic vapours, the approach is restricted to light with wavelengths matching the natural resonances of atoms.
The new approach – called OMIT, or optomechanically induced transparency – is based on optomechanical coupling of photons with mechanical oscillations inside an optical microresonator. When light is coupled into the resonator, the photons exert radiation pressure. This usually small force is enhanced within an optical microresonator and can deform the cavity, coupling the light to the mechanical vibrations. A control laser can be coupled to the resonator and the beating of the two lasers causes the mechanical oscillator to vibrate. This prevents signal light entering the resonator.
Future developments of the approach could enable the conversion of a stream of photons into mechanical excitations (phonons) to allow optical based narrow band filtering. OMIT could also realise buffers that allow optical information to be stored for several seconds.
