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Improving Internet with mid-wavelength infrared

Novel phototransistor device could result in faster, cheaper Internet

Date:
July 26, 2016
Source:
Northwestern University
Summary:
A novel phototransistor device could make the Internet faster and cheaper by replacing near-infrared wavelengths with mid-wavelength infrared, say scientists.
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With a growing number of people connecting to the Internet everyday, Internet cables are under the threat of a "bandwidth explosion."

Free-space optical (FSO) communication is a promising candidate to lighten the load. FSO uses visible or infrared light to wirelessly transmit data through open air as opposed to using cables, which have limited bandwidth. The new technology provides a low-cost and low-power alternative to traditional radio-frequency wireless data links.

"The current state-of-the-art in FSO communications is based around near-infrared sources and photodetectors," said Northwestern University's Manijeh Razeghi. "Unfortunately, using these wavelengths come with major problems."

At high power, near-infrared wavelengths can damage the human eye, and they are hampered by atmospheric scattering and absorption. Razeghi, who leads Northwestern's Center for Quantum Devices, has bypassed this issue by using mid-wavelength infrared radiation, which can benignly and flawlessly transmit through fog, smoke, and clouds.

Razeghi and her team have 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.

On July 12, the research was published online in Applied Physics Letters. Abbas Haddadi, a postdoctoral fellow in Razeghi's laboratory, was first author of the paper.

"For the first time, we have demonstrated a phototransistor that is totally made of an artificial semiconductor," said Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science in Northwestern's McCormick School of Engineering. "This extremely sensitive device could be a game changer for FSO communication technology by providing low-cost, high-speed data links."


Story Source:

Materials provided by Northwestern University. Note: Content may be edited for style and length.


Journal Reference:

  1. A. Haddadi, S. Adhikary, A. Dehzangi, M. Razeghi. Mid-wavelength infrared heterojunction phototransistors based on type-II InAs/AlSb/GaSb superlattices. Applied Physics Letters, 2016; 109 (2): 021107 DOI: 10.1063/1.4958715

Cite This Page:

Northwestern University. "Improving Internet with mid-wavelength infrared." ScienceDaily. ScienceDaily, 26 July 2016. <www.sciencedaily.com/releases/2016/07/160726123714.htm>.
Northwestern University. (2016, July 26). Improving Internet with mid-wavelength infrared. ScienceDaily. Retrieved March 18, 2024 from www.sciencedaily.com/releases/2016/07/160726123714.htm
Northwestern University. "Improving Internet with mid-wavelength infrared." ScienceDaily. www.sciencedaily.com/releases/2016/07/160726123714.htm (accessed March 18, 2024).

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