New device may lead to faster, cheaper internet

New York:Researchers have developed a novel photo- transistor device that provides a low-cost and low-power alternative to traditional radio-frequency wireless data links, thus lightening the load on internet cables which are under the threat of a "bandwidth explosion." "The current state-of-the-art in FSO (free-space optical) communications is based around near-infrared sources and photodetectors," said Northwestern University's Manijeh Razeghi. But unfortunately, using these wavelengths come with major problems", she added. At high power, near-infrared wavelengths can damage the human eye, and they are hampered by atmospheric scattering and absorption. However, Razeghi's team bypassed this issue by using mid-wavelength infrared radiation, which can benignly and flawlessly transmit through fog, smoke and clouds. The team developed an extremely sensitive mid-wavelength infrared photodetector that has potential to replace near-infrared FSO communications links in many applications.  Called a phototransistor, the novel device is a combination of an electronic transistor and optoelectronic photodiode.  "This extremely sensitive device could be a game changer for FSO communication technology by providing low-cost, high-speed data links," Razeghi said in a paper appeared in the journal Applied Physics Letters.