Thursday, October 05, 2006

"Feel" The Light

Wico Hopman (you have to love those Dutch names), a graduate student at the university of Twente, has managed to actually feel the wave pattern of photons trapped in an optical cavity fashioned from a tuned photonic crystal. His paper entitled "Nano-mechanical tuning and imaging of a photonic crystal micro-cavity resonance" describes how he uses an Atomic Force Microscope to image the trapped photons, and further, actually manipulate the wavelength tuning of the cavity by dipping the microscope probe tip into the cavity.

The photonic crystal trap is fashioned by etching holes in a very precise grid tuned to match the wavelength of light to be trapped, and leaving a small cavity with no holes that will act as a resonant cavity to confine the photons of a particular color. The resulting trap is therefore a very precise and effective color filter.

Hopman was then able to use the probe tip to map the field strength across the cavity,

and even affect the wavelength tuning of the cavity using the probe tip. Since the color selectivity can be regulated by moving the probe tip less than a few nanometers, a very simple setup that shines a monochromatic source through the tunable trap promises a very fast opto-mechanical switching device.

The full article can be found here at Optics Express.

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