US 11,757,529 B1
Reducing scintillation noise in free space optical communications
Thomas M. Chaffee, Lexington, VA (US); Wayne H. Knox, Rochester, NY (US); Alexander B. LeBon, Lexington, VA (US); Brian M. Gregory, Lexington, VA (US); and Taz M. Colangelo, Lexington, VA (US)
Assigned to Attochron, LLC, Lexinton, VA (US)
Filed by Attochron, LLC, Lexington, VA (US)
Filed on Feb. 6, 2023, as Appl. No. 18/164,947.
Application 18/164,947 is a continuation of application No. 17/932,364, filed on Sep. 15, 2022, granted, now 11,575,433.
This patent is subject to a terminal disclaimer.
Int. Cl. H04B 10/112 (2013.01)
CPC H04B 10/1123 (2013.01) [H04B 10/1129 (2013.01)] 16 Claims
OG exemplary drawing
1. An optical communication system for optically transmitting data through a variably refractive medium, the optical communication system comprising:
an optical source configured to generate a beam comprising a series of light pulses;
a modulator configured to modulate the series of light pulses in response to a data transmission signal, thereby encoding transmission data into the series of light pulses;
a photoreceiver, the photoreceiver having:
a detection window duration of 1 nanosecond or less; and
a detection threshold, wherein the photoreceiver is configured to indicate whether a received optical energy during a given detection window is greater than the detection threshold;
the series of light pulses comprises a first pulse having a coherence length of less than 400 microns;
when the first pulse travels through the variably refractive medium, photons in the first pulse are refracted to travel along different ray paths having different lengths to the photoreceiver;
the photons of the first pulse arrive at the photoreceiver according to a temporal distribution curve that depends, at least in part, on a duration of the first pulse and lengths of the different ray paths taken by the photons in the first pulse to the photoreceiver;
a full width at half-maximum value (FWHM value) of the temporal distribution curve is greater than a coherence time value equal to the coherence length of the first pulse divided by a speed of light through the variably refractive medium; and
the detection window duration of the photoreceiver is greater than the FWHM value of the temporal distribution curve.