Wednesday, October 06, 2010

#OPTICS Microscopic Antennas for Light Beat Fiber Optics

Optical signals use light not only for telecommunications, but for sensors that can detect even scant amounts of toxins. Most optical signals are routed down fibers like a conduit, but now Rice University researchers are proposing to use microscopic optical antennas to receive light in the same way a cell phone's antenna receives radio waves. Look for super-sensitive detectors built using optical antennas within five years. RColinJohnson @NextGenLog

Artist's rendering of how plasmons in a pair of gold sub-nanometer electrodes concentrate light from a laser. (Image courtesy Natelson Lab/Rice University)
Electromagnetic radiation runs the gamut from long-wavelength radio waves to short-wavelength light waves, but antennas are usually thought of as useful only for radio waves. Since an antenna's size is related to the wavelength it is intended to receive, radio antennas must be a millimeter or longer. Since light's wavelength is measured in nanometers, antennas scaled down to that size should be able to receive the nanometer wavelengths of light.
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