Greg, here's where MRV et al will be going with new OEM products:
A conventional fiber optic cable that transmits telephone signals over long distances is a lot like a garden hose. Instead of water, though, light pours through it, contained by its walls.
But a new, extremely tiny light guide is designed quite differently. Instead of holding the light in, this nanoscale fiber lets about half its light energy flow outside in a glowing, evanescent field. It acts "like a rail for the light," said Eric Mazur, a professor of physics at Harvard University who led the research team that developed what are called optical nanowires.
The nanowires, made of glass, are very small - some are 50 nanometers, or 50 billionths of a meter, in diameter, or about one-thousandth the diameter of a human hair. Because the diameters are smaller than the wavelength of the transmitted light, the nanowires become the path around which the light waves flow. The thinner the wire, the more energy goes into the evanescent field around it.
In one of their experiments, for example, the Harvard team used a nanowire with a diameter of 360 nanometers to guide light with a wavelength of 633 nanometers.
The wires are meant not for the long hauls of conventional fiber optic cables that run between cities and under oceans, Dr. Mazur said, but for distances measured at most at an inch or so. For instance, they might be used as practical low-loss interfaces between optical fiber and the devices that process optical and electronic signals, making more compact, faster processors possible.
Right now, a standard fiber optic cable (which is closer to a human hair in diameter) carries thousands of conversations, each at a slightly different wavelength, that are combined through a process called multiplexing. But at journey's end, these light signals must be processed and converted to electronic signals. The new wire may one day be part of this processing, in tiny multiplexers that combine conversations and send them along, or demultiplexers at the other end that separate the signals into their individual components.
The balance can be found at:
nytimes.com
Dee Jay |
