Systems and Methods for Free Space Optical Communication

Patent ID: 5919 | Patent Number 7,941,050 | Status: Granted


We have adapted a variation of wavelength modulated (WM) spectroscopy to develop a long distance free space optical communications (FSOC) technique that is resistant to both atmospheric turbulence and atmospheric visibility changes ¡V two key parameters that currently limit FSOC implementation. The technology uses long wave infrared (LWIR) because this wavelength transmits best through fog, etc and cannot be seen by human bystanders. The technology uses quantum cascade laser (QCL) wavelength modulation (WM) to toggle between two bit states +1 and -1, and uses our patented intensity normalization routine to further cancel turbulence noise. The (+1, -1) bit protocol eliminates false 0 bit readings caused by turbulence induced intensity fluctuations. The bit error rate (BER) of our novel system will be extremely low, and the transmit distance should be at least 20 km.

Application Number



Harper,Warren W
Pratt,Rick M
Aker,Pam M

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