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Ewing, NJ - October 2, 2008
Discovery Semiconductors (DSC), Air Force Research Laboratory, Space Vehicles Directorate (AFRL/RV), Science Applications International Corp. (SAIC), and Schafer Corp. have collaborated on a 10Gb/s free space optical (FSO) communications link. It was demonstrated that more than 80 dB of link loss can be overcome with this system [1]. Dr. Christoph Wree, the Program Manager at DSC said, “The 10Gb/s system uses a wavelength of 1550nm where powerful optical amplifiers can be used to boost the transmitted signal and pre-amplify the received signal. The use of differential phase-shift keying (DPSK) gave us an excellent receiver sensitivity of 27 photons/bit at a bit error ratio of 1e-9. This is only 5 photons away from the quantum limit.” Patrick Collier from SAIC tested the system at the Kirtland Air Force Base (NM) in the presence of atmospheric turbulence. He added, “In comparison to other investigated modulation formats, RZ-DPSK showed the best resilience against scintillation effects introduced by atmospheric effects.”
The use of FSO comm links allows Air Force to increase the data rate and reduce the space, weight, and power consumption with respect to RF comm links. This FSO project demonstrates that the system can overcome large link losses which can be introduced either by ultra long inter-satellite link distances or by link losses arising from atmospheric turbulence. This makes the 10Gb/s RZ-DPSK system a promising candidate for future FSO comm links.
[1] Presented at SPIE Free Space Laser Communications Conference, San Diego, CA, August 2008, Paper 7091-2.
Discovery Semiconductors is an industry leader in manufacturing ultrafast, high optical power handling InGaAs photodiodes, radio frequency over fiber optical receivers, balanced optical receivers and several other custom products for applications ranging from analog RF links to ultrafast digital communications. Discovery’s subsystems include Kitty Hawk, an ultra-fast Optical Coherent System.
For additional information, including complete product specifications, operational capabilities and pricing, or to discuss your application in detail, please call Discovery at: (609) 434-1311 or fax: (609) 434-1317.
