kimjinbu 2008-08-26 16:58
IBM makes first steps toward carbon nanotube-based
IBM said its scientists furthered the development of carbon nanotube transistor devices by controlling the light emission from a nanotube, and by manipulating and directing light from a single carbon nanotube. As such, the researchers achieved this milestone in the potential development of nanotube-based “nanophotonic” devices, with the goal of building ICs that manipulate light signals, similar to the way electrical signals are manipulated in today’s silicon-based computer chips.?P*xna3[
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This development involved a series of steps, with the first being IBM scientists combining a single nanotube-based field-effect-transistor (FET) with a pair of metallic nano-mirrors on a chip. The scientists said they were then able to control the optical emission properties from the nanotube which is 2-nm in diameter, including the emission wavelength, the spectral and spatial distribution of the emitted light, and even the efficiency of the emission.)G p0Lq"I
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This work demonstrates an unprecedented level of control over electrically-driven light nano-emitters, IBM believes.
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IBM said that scientists have known how to control the emission from optically active materials for some time using optical cavities, in which light can bounce back and forth, and interact with the active materials and the cavity leading to emitted light whose characteristics are dominated by the cavity structure, with the laser being one example of a cavity-controlled light source. J^ [D$xPAR+j3VN-V
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By proving that nano-cavities can be used to control and improve the properties of individual, single-walled carbon nanotubes, IBM said its researchers have opened up the possibility of their use in integrated nanophotonic circuits, quantum optics and high performance, on-chip optical interconnects and sensors.
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The technology is described in detail in the journal Nature Nanotechnology.