# US 12,113,580 B1 · Reducing scintillation noise in free-space optical communications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,580 B1 - Document ID: US12113580B1 - Status: Granted - Kind: B1 - Application number: 18/644,738 - Filed: 2024-04-24 - Published: 2024-10-24 - Granted: 2024-10-08 - Earliest claimed: 2023-04-20 - Assignees: Attochron, LLC - Applicants: Attochron, LLC - Inventors: Thomas M. Chaffee; Wayne H. Knox; Alexander B. LeBon; Brian M. Gregory; Taz M. Colangelo - Web page: https://patentgrep.com/patent/US12113580B1 ## CPC - H04B 10/118: specially adapted for satellite communication - H04B 10/697: {Arrangements for reducing noise and distortion} - H04B 10/116: Visible light communication - H04B 10/556: Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK] - H04B: TRANSMISSION ## Abstract System, method, and instrumentalities are described herein for transmitting information optically. The optical source may be configured to generate a beam. The beam may include a series of light pulses. The beam of light may be modulated. A modulator may be 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. The modulated beam of light may be received and both amplified and filtered. The filtered beam of light may be transmitted from to a detector having a photoreceiver. The photoreceiver may be configured to extract the transmission data from the filtered beam of light. ## Claims ### Claim 1 An optical system, the optical system comprising: an optical source configured to generate a first beam of light, wherein the first beam of light has a first signal-to-noise ratio; an optical modulator configured to receive the first beam of light and generate a modulated first beam of light; and an optical amplifier, wherein the optical amplifier is configured to receive the modulated first beam of light and produce a second beam of light, the second beam has a second signal-to-noise ratio, and the second signal-to-noise ratio is at least three times as large as the first signal-to-noise ratio, wherein the optical system is configured to transmit the second beam of light, through a variably refractive medium, to a detector having a photoreceiver, and wherein the optical source is a superluminescent diode (SLED), and the optical amplifier is a filter that amplifies the first beam of light and reduces high frequency noise. ### Claim 2 (depends on 1) The optical system of claim 1, wherein the optical source and the detector are spaced by a free space optical distance between 0.5 miles and 20 miles, and the optical system has a measured error rate between one in one million and one in one quadrillion over the free space optical distance for a measurement period of at least sixty seconds. ### Claim 3 (depends on 1) The optical system of claim 1, wherein the optical amplifier has an optical gain between 5 and 30,000. ### Claim 4 (depends on 1) The optical system of claim 1, wherein the optical amplifier is a fiber amplifier comprising at least a core and cladding, the cladding surrounds the core, the cladding comprises a transition metal ion compound, and the transition metal ion compound is at least one of Erbium, Ytterbium, Neodymium, or Terbium. ### Claim 5 (depends on 1) The optical system of claim 1, wherein the optical source is located on a ground station and the photoreceiver is disposed on an earth-orbiting satellite, and the optical system has a measured error rate of between one in one billion and one in one quadrillion over a free space optical distance between the ground station and the earth-orbiting satellite for a measurement period of at least sixty seconds. ### Claim 6 (depends on 1) The optical system of claim 1, wherein the optical system is a data communications system. ### Claim 7 (depends on 1) The optical system of claim 1, wherein: the second beam of light includes photons that travel along a plurality of ray paths having different lengths to the photoreceiver; the photons arrive at the photoreceiver according to a temporal distribution curve that depends, at least in part, on the different lengths of the plurality of ray paths; and a full width at half maximum (FWHM) value of the temporal distribution curve is at least three times as large as a coherence time value equal to a coherence length divided by a speed of light through the variably refractive medium. ### Claim 8 (depends on 1) The optical system of claim 1, wherein the optical amplifier is a first optical amplifier, and the optical system further comprises a second optical amplifier, wherein the first optical amplifier transmits the first beam of light to the second optical amplifier. ### Claim 9 (depends on 1) The optical system of claim 1, wherein the optical system is a lidar system. ### Claim 10 (depends on 1) The optical system of claim 1, wherein the optical system is at least one of: (i) a remote sensing system; (ii) a power beaming system, or (iii) a beacon system. ### Claim 11 (depends on 1) The optical system of claim 1, wherein the optical system comprises a plurality of optical sources configured to generate respective beams of light, and the respective beams of light are coupled to a multiport coupler. ### Claim 12 A method of an optical system, the method comprising: generating, by an optical source, a first beam of light, wherein the first beam of light has a first signal-to-noise ratio; receiving, by an optical modulator, the first beam of light and generating a modulated first beam of light; receiving, by an optical amplifier, the modulated first beam of light to produce a second beam of light; wherein the second beam has a second signal-to-noise ratio, and the second signal-to-noise ratio is at least three times as large as the first signal-to-noise ratio; and transmitting the second beam of light through a variably refractive medium to a detector having a photoreceiver, wherein the optical source is a superluminescent diode (SLED), and the optical amplifier is a filter that amplifies the first beam of light and reduces high frequency noise. ### Claim 13 (depends on 12) The method of claim 12, wherein the optical source and the detector having the photoreceiver are spaced by a free space optical distance between 0.5 miles and 20 miles, and the second beam of light has a measured error rate between one in one million and one in one quadrillion over the free space optical distance for a measurement period of at least sixty seconds. ### Claim 14 (depends on 12) The method of claim 12, wherein the optical amplifier has an optical gain between 5 and 30,000. ### Claim 15 (depends on 12) The method of claim 12, wherein the optical amplifier is a fiber amplifier that includes a transition metal ion compound, and the transition metal ion compound includes at least one of Erbium, Ytterbium, Neodymium, or Terbium. ### Claim 16 (depends on 12) The method of claim 12, wherein the optical source is located on a ground station and the photoreceiver is disposed on an earth-orbiting satellite, and the second beam of light has a measured error rate between one in one billion and one in one quadrillion over a free space optical distance between the ground station and the earth-orbiting satellite for a measurement period of at least sixty seconds. ### Claim 17 (depends on 12) The method of claim 12, wherein the optical system is a data communications system. ### Claim 18 (depends on 12) The method of claim 12, wherein: the second beam of light includes photons that travel along a plurality of ray paths having different lengths to the photoreceiver; the photons arrive at the photoreceiver according to a temporal distribution curve that depends, at least in part, on the different lengths of the plurality of ray paths; and a full width at half maximum (FWHM) value of the temporal distribution curve is at least three times as large as a coherence time value equal to a coherence length divided by a speed of light through the variably refractive medium. ### Claim 19 (depends on 12) The method of claim 12, wherein the optical amplifier is a first optical amplifier, and the first optical amplifier transmits the second beam of light to a second optical amplifier. ### Claim 20 (depends on 12) The method of claim 12, wherein the optical system is at least one of: (i) a remote sensing system; (ii) a power beaming system, (iii) a beacon system, or (iv) a lidar system.