Free-Space Optical Channel Using Multi-Core Fibers for Low Latency

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Solution Overview

Problem

Existing high-speed optical communication systems using hollow core fibers face manufacturing challenges, high costs, fragility, and significant propagation delays due to the refractive index of glass, which are not suitable for high-speed trading applications.

Innovation Solution

A low latency free-space optical data communication channel using multi-core optical fibers with collimators and channel raceways, enabling optical signals to propagate through air, minimizing divergence and using optical splitters for power monitoring, thereby reducing latency and eliminating the need for expensive hollow core fibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If hollow core fibers are used to reduce propagation delay, then the optical signal speed approaches the speed of light in vacuum, but the manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improvepropagation delayVSAvoidmanufacturing complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The invention uses multi-core optical fibers where each core can be independently manufactured and then assembled into a bundled cable structure. This segmentation allows standard manufacturing processes to be used for each core, avoiding the complex single hollow core structure while achieving similar low-latency performance through parallel optical paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs conventional optical fiber technologies that are already mass-produced and cost-effective, rather than expensive custom hollow core fibers. By using standard fiber drawing processes and assembly techniques, the solution achieves low propagation delay without the hundreds-to-thousands of dollars per meter cost of hollow core alternatives.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Loss of time

If hollow core fibers are used to reduce propagation delay, then the optical signal speed approaches the speed of light in vacuum, but the fiber becomes fragile and susceptible to degradation

Engineering Contradiction:
Improvepropagation delayVSAvoidfiber robustness
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The invention creates a composite cable structure containing multiple discrete optical fiber cores, each protected by standard fiber coatings and buffering. This composite approach combines the low-latency benefit of air-equivalent propagation paths with the mechanical robustness of conventional fiber protection structures, eliminating the fragility of single hollow core designs.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

By dividing the optical transmission function across multiple separate cores rather than relying on a single hollow core structure, the invention distributes mechanical stress and damage risk. Each core can be independently protected and replaced if needed, significantly improving overall system reliability compared to fragile hollow core alternatives.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If standard optical fibers are used for communication, then the system is robust and easy to manufacture, but the propagation delay is significant due to the refractive index of glass

Engineering Contradiction:
Improvemanufacturing easeVSAvoidpropagation delay
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The invention introduces an intermediary air-filled space or low-refractive-index material structure between the optical signal paths, allowing light to travel at speeds closer to vacuum speed while still maintaining the mechanical protection and manufacturing advantages of conventional fiber cable structures. This intermediary structure reduces the effective refractive index without sacrificing robustness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the optical transmission into multiple discrete channels that can be routed through paths with reduced refractive index materials or air gaps, while the overall cable assembly maintains standard manufacturing processes. This allows selective optimization of propagation speed for critical channels while keeping the rest of the system simple to manufacture.

Inventive Principle:
Principle #1Segmentation

4Loss of time

If custom manufactured fiber cable assemblies with precisely measured fiber lengths are used, then equivalent trading delays are guaranteed, but the cost and manufacturing complexity increase

Engineering Contradiction:
Improvedelay equivalenceVSAvoidmanufacturing precision requirements
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The invention uses multiple discrete optical cores within a cable assembly, where each core's length can be independently controlled during the standard fiber drawing process. This segmentation allows for easier length matching and delay equalization compared to single custom-manufactured fibers, as length precision can be achieved through conventional manufacturing tolerances rather than post-manufacturing measurement and selection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs parameter control during standard fiber manufacturing processes to achieve consistent lengths and propagation characteristics across multiple cores. By controlling parameters such as draw speed, temperature, and tension during fiber production, the system achieves equivalent propagation delays without requiring expensive custom manufacturing and OTDR measurement processes.

Inventive Principle:
Principle #35Parameter changes

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 solution provides low latency optical signal paths with equivalent propagation delays, reducing costs and enhancing system robustness, suitable for high-speed trading and data center applications.

Implementation Method 1

optical communication signals to propagate through free-space, thereby traveling at the speed of light in air minimizing propagation time

Methodology Applied
Scientific EffectLight propagation: Light

Implementation Method 2

at least two opposing optical collimators for transmitting an optical communication signal in the form of a parallel beam across a free-space channel

Methodology Applied
Scientific EffectCollimation: Lens

Implementation Method 3

hollow core fibers, where the core is a channel of air surrounded by an array of hollow tubes which form reflective micro-structures cladding, to confine the optical beam

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 4

using optical splitters for power monitoring

Methodology Applied
Scientific EffectOptical splitting:

Implementation Method 5

The speed of an optical signal is determined by the refractive index of the medium in which it propagates, where the refractive index is effectively the optical dielectric constant of the medium

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4345518B1Apparatus and method for low latency free-space optical communications
Publication Date: 2026.04.22 PANDUIT CORP
  • EP4345518B1 patent drawingFigure 1
  • EP4345518B1 patent drawingFigure 2
  • EP4345518B1 patent drawingFigure 3

AI summary

A low latency free-space optical data communication channel has at least two opposing optical collimators for transmitting an optical communication signal in the form of a parallel beam across a free-space channel. The input of the collimators are multi-core optical fibers. Multiple cores of the multi-core optical fibers are positioned at the focal point of the two opposing optical collimators. The optical collimators image the communications signals in each of the cores of the multi-core fibers into the corresponding cores of the opposing multi-core fibers.