Non-Linear Properties of Graphene May Enable Photonic ComputingCategory: Science & Technology
Posted: July 23, 2012 10:08AM
Silicon, the modern backbone of electronics, and its potential successor, graphene, have teamed up to create a device with extraordinary non-linear optical properties. Researchers at Columbia University and the Institute of Microelectronics in Singapore discovered a device that can generate and control multiple frequencies of light by just manipulating the input laser and the responses of the material.
Linear optics are what most people are familiar with as they expect that when they look through a window to see what is on the other side as though the window were not there. Non-linear optics however have the ability to shift the wavelengths of light which passes through it. A non-linear window could, in principle, make green grass look blue and the blue sky invisible, as our eyes cannot see ultraviolet light.
When the researchers shined a laser onto the silicon-graphene photonic crystal they found they could control the output light's transmittance and wavelength by manipulating the power of the laser. Also, by optically controlling the electronic and thermal properties of the photonic material the researchers were able to generate a radio frequency carrier on top of the output light. By careful tweaking of the laser's intensity and frequency they were able to control the radio frequency's modulation. All of this was accomplished at considerably lower energy levels than other photonic crystals require.
Such functionality at low power gives this technology the capability to be used within computer chips. As photons travel faster than electrons, this could aid in the development of advanced optical telecommunications that operate at great speed, while still being on a chip.