US 12,250,021 B1
Active feedback noise reduction for free space optical communications
Thomas M. Chaffee, Lexington, VA (US); and Wayne H. Knox, Rochester, NY (US)
Assigned to Attochron, LLC, Lexington, VA (US)
Filed by Attochron, LLC, Lexington, VA (US)
Filed on Oct. 22, 2024, as Appl. No. 18/922,680.
Application 18/922,680 is a continuation in part of application No. 18/811,592, filed on Aug. 21, 2024.
Int. Cl. H04B 10/077 (2013.01); H04B 10/50 (2013.01)
CPC H04B 10/0773 (2013.01) [H04B 10/0775 (2013.01); H04B 10/5057 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An optical communication system using active feedback noise reduction for optically transmitting data through a variably refractive medium, the optical communication system comprising:
an optical signal generator, wherein the optical signal generator includes:
an optical source configured to generate a beam of light;
a first modulator configured to encode data on the beam of light to form an encoded beam of light; and
an amplifier configured to receive the encoded beam of light from the first modulator and both amplify and filter the encoded beam of light to produce an amplified beam of light;
a telescope, wherein the telescope is configured to:
transmit the amplified beam of light through a variably refractive medium, and
receive an inbound beam of light; and
a detector system, wherein the detector system includes:
at least one detector;
a routing system that includes optical components and/or fiber components, wherein the routing system transmits a first portion of the inbound beam of light to a first detector of the at least one detector; and
a noise reduction system, wherein the noise reduction system includes:
a splitter configured to obtain a second portion of the inbound beam of light;
a second detector configured to receive the second portion of the inbound beam of light and generate a sampled signal;
a controller configured to receive the sampled signal and generate a control signal; and
a second modulator configured to receive the control signal and attenuate, based on the control signal, the first portion of the inbound beam of light before it is detected by the first detector, thereby reducing a variable noise caused by the variably refractive medium.