FSO Transmitter Alignment Beam Modulation for Turbulence Compensation

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Solution Overview

Problem

Free Space Optical (FSO) communication systems are prone to disruptions due to atmospheric turbulence, which affects the alignment of transmitting beams and reduces communication reliability and distance.

Innovation Solution

An optical communication transmitter and receiver system that uses a combination of optical communication and alignment beams to encode and decode directional data, allowing for improved beam alignment and stability through modulation of beam properties and use of variable optical elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If FSO communication uses line-of-sight technology, then communication can be established, but alignment is easily impaired due to atmospheric turbulence

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidatmospheric turbulence impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system transmits alignment data through the alignment beam before or during communication to enable the receiver to pre-adjust or continuously correct beam alignment, compensating for atmospheric turbulence effects before they cause communication failure

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The receiver measures the actual beam arrival direction and compares it with the transmitted alignment data to generate feedback signals, enabling real-time adjustment of the beam pointing direction to maintain communication reliability despite atmospheric conditions

Inventive Principle:

Principle #23Feedback

2Ease of operation

If alignment beams are used to transmit directional data, then alignment maintenance is simplified, but system complexity increases

Engineering Contradiction:

Improvealignment maintenanceVSAvoidsystem complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the alignment function and data transmission function into a single alignment beam, eliminating the need for separate alignment signals and simplifying the overall system architecture while maintaining ease of alignment maintenance

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The alignment beam serves multiple functions: it provides directional alignment information, transmits communication data, and enables beam tracking, reducing the number of separate components needed and simplifying system operation

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If beam alignment is continuously adjusted, then communication stability improves, but energy consumption increases

Engineering Contradiction:

Improvebeam alignment stabilityVSAvoidenergy consumption

Core Design Contradiction:

Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The system performs alignment adjustments periodically based on atmospheric conditions and beam drift rates rather than continuously, reducing energy consumption while maintaining sufficient alignment stability for reliable communication

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The alignment adjustment frequency and intensity are dynamically adapted based on real-time atmospheric turbulence measurements and communication requirements, allowing the system to reduce energy consumption during stable conditions while maintaining stability when needed

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enhances the reliability and range of FSO communications by simplifying alignment maintenance, detecting environmental parameters, and compensating for beam misalignments, thereby reducing downtime and increasing communication efficiency.

Implementation Method 1

at least one alignment modulator, configured and arranged to receive data and to vary one or more properties of the at least one first optical alignment beam corresponding to data to be communicated

Methodology Applied

Scientific EffectOptical modulation: Phase Modulation

Implementation Method 2

This turbulence is frequently caused by localized changes of refractive indexes due to variations in one or more environmental parameters, such as wind velocity or humidity. This affects the pointing of the one or more transmitting beams between the transmitter and receiver since every time the beam crosses the interface between two areas with different refractive index it slightly changes its direction.

Methodology Applied

Scientific EffectAtmospheric refraction: Refraction

Data Source

PatentUS12212366B2Optical communication transmitter and receiver with misalignment measurement and correction

Publication Date: 2025.01.28 AIRCISION TECHNOLOGIES BV

AI summary

FSO systems rely on line-of-sight, and thus can be easily impaired due to disruptions such as atmospheric turbulence. There is a need for a more robust communication system allowing longer distances to be bridged and/or downtime to be reduced.An optical transmitter is provided generating at least one optical alignment beam. The transmitter comprises at least one alignment modulator, to modulate the alignment beam with transmitter directional data. A suitable receiver may demodulate this information and use the directional data from the transmitter to simplify the attainment and/or maintenance of a sufficient degree of alignment.Additionally or alternatively, the at least one alignment beam may be used to detect, characterize and/or monitor one or more environmental parameters.