Multi-Electrode Plasma System for Uniform Optical Fiber Heating

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Solution Overview

Problem

Current optical fiber splicing and stripping technologies face challenges with uneven heating due to the dielectric nature of large diameter fibers and combustible coatings, leading to poor splice quality and coating decomposition, especially when using arcs for thermal processing.

Innovation Solution

A multi-electrode system configured to operate in a partial or complete vacuum, utilizing three electrodes to generate a uniform plasma field around the fiber, reducing convection and dielectric interference, and allowing for lower power arc initiation and maintenance, which prevents coating combustion and achieves even heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single arc source is used for heating large diameter fibers, then the heating process is simpler, but the heating uniformity deteriorates due to dielectric nature causing arc to curve around fiber

Engineering Contradiction:
Improveheating system complexityVSAvoidheating uniformity
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The single arc source is segmented into multiple arc sources (at least three electrodes) distributed around the fiber. Each electrode generates its own arc discharge, and the combined effect creates uniform heating around the entire circumference of the fiber, preventing the arc from curving around the fiber due to dielectric effects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple arc discharges from different electrodes are merged to create a combined heating effect. The plasma fields from individual arcs overlap and combine to produce a uniformly distributed thermal field around the fiber, achieving both simplicity and uniformity.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If conventional arc stripping is used, then the stripping process is simpler, but the coating combustion occurs due to uneven heating and excessive temperature

Engineering Contradiction:
Improvestripping system complexityVSAvoidcoating combustion
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The concentrated arc heating is segmented into multiple distributed arc sources. This distributes the thermal energy more evenly around the coating, preventing localized overheating that would cause combustion while still achieving effective coating removal through controlled thermal decomposition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heating parameters are changed by using multiple electrodes with controlled voltage and spacing. This allows better control of the plasma temperature and energy distribution, maintaining temperatures sufficient for coating decomposition but below the combustion threshold.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If larger electrode spacing is used to accommodate larger fibers, then the fiber size compatibility is improved, but the voltage required to initiate discharge increases according to Paschen's Law

Engineering Contradiction:
Improvefiber size compatibilityVSAvoidinitiating voltage
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

Different regions of the electrode assembly have different properties. The electrodes are positioned and sized to create appropriate local electric field conditions. This allows the system to accommodate larger fiber diameters while maintaining effective discharge initiation through optimized local electrode geometry and spacing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

A vacuum environment is introduced as an intermediary medium between the electrodes and the surrounding atmosphere. This reduces the gas pressure, which according to Paschen's Law decreases the breakdown voltage for larger gaps, allowing larger electrode spacing for bigger fibers while reducing the initiating voltage requirement.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If arc heating is used in atmospheric conditions, then the system operation is simpler, but convection causes isothermic instability and reduces heating precision

Engineering Contradiction:
Improvesystem operation complexityVSAvoidtemperature control precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

A vacuum chamber is introduced as an intermediary environment to eliminate convective heat transfer. By removing the atmospheric gas, convection currents that cause temperature fluctuations and isothermic instability are eliminated, resulting in more precise and stable temperature control during the heating process.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides enhanced isothermic stability and reduced electrode oxidation, enabling precise temperature control and uniform heating of fibers, improving splice quality and coating removal without combustion, and accommodating larger diameter fibers.

Implementation Method 1

electrodes configured to generate arcs between adjacent electrodes to produce a substantially uniform heated field about an outer surface of the at least one optical fiber

Methodology Applied
Scientific EffectArc discharge: Electric Arc

Implementation Method 2

arcs between adjacent electrodes to produce a substantially uniform heated plasma field about an outer surface of the at least one optical fiber

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 3

When provided in a partial or complete vacuum, such systems and methods provide enhanced isothermic stability of the plasma field due to the elimination (or reduction) of convection

Methodology Applied
Scientific EffectConvection reduction: Convection

Implementation Method 4

arcs between adjacent electrodes to produce a substantially uniform heated plasma field about an outer surface of the at least one optical fiber

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP2115505B1Multi-electrode system
Publication Date: 2020.05.27 SAE TECH INC
  • EP2115505B1 patent drawingFigure 1A~1B
  • EP2115505B1 patent drawingFigure 2A~2C
  • EP2115505B1 patent drawingFigure 3

AI summary

A multi-electrode system comprises a fiber support configured to hold at least one optical fiber and a set of electrodes disposed about the at least one optical fiber and configured to generate arcs between adjacent electrodes to generate a substantially uniform heated field to a circumferential outer surface of the at least one optical fiber. The electrodes can be disposed in at least a partial vacuum.