Ferrule-less Optical Fiber Alignment Using Elastic Pre-buckling

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Solution Overview

Problem

Ferrule-less optical fiber connection systems using V-grooves face issues with energy loss due to fiber behavior during connection, necessitating improvements in alignment and retention mechanisms.

Innovation Solution

The method involves orienting an optical fiber within an alignment groove, causing it to elastically flex, and using an interference point at least 1.5 millimeters from the mid-plane to form a curved profile, leveraging the fiber's elasticity to maintain contact with the groove, and incorporating a pre-buckling protrusion to stabilize the fiber before connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If ferrule-less optical fiber connection systems use V-grooves for alignment, then device complexity is reduced, but energy loss increases due to fiber behavior during connection

Engineering Contradiction:

Improvealignment device structureVSAvoidoptical energy loss

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The fiber is pre-buckled before connection by engaging it with a pre-buckling protrusion that causes the fiber to have a pre-buckled configuration. This preliminary action stabilizes the fiber profile before the connection event, preventing excessive bending stresses during mating and reducing optical energy loss.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

An interference point is introduced as an intermediary element at least 1.5mm from the mid-plane to assist in forming a controlled curved profile of the flexed fiber. This intermediary structure guides the fiber bending behavior and maintains stable contact with the alignment groove, reducing energy loss without requiring complex ferrule structures.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the fiber is allowed to flex freely during connection, then ease of operation is improved, but reliability decreases due to bending stresses

Engineering Contradiction:

Improvefiber insertionVSAvoidconnection stability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The fiber configuration is changed from a straight state to a pre-buckled state with a controlled curved profile. By modifying the fiber's physical state before connection, the system achieves both ease of insertion and improved reliability through reduced bending stresses during the connection process.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The pre-buckling protrusion provides beforehand cushioning by creating a controlled buckle in the fiber before connection. This preliminary cushioning prevents excessive bending stresses during the connection event, protecting the fiber from damage while maintaining ease of operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the interference point is placed close to the mid-plane, then device complexity is reduced, but manufacturing precision requirements increase to maintain alignment

Engineering Contradiction:

Improvealignment structureVSAvoidfiber alignment accuracy

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The interference point serves as an intermediary element positioned at least 1.5mm from the mid-plane. This positioning creates a lever arm that amplifies alignment tolerance, reducing manufacturing precision requirements while maintaining alignment accuracy through the controlled formation of the fiber's curved profile.

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

This approach reduces bending stresses, enhances long-term reliability, and minimizes insertion loss by ensuring precise alignment and stable contact between optical fibers, improving the overall performance of the optical connection system.

Implementation Method 1

causing the optical fiber to elastically flex; using inherent elasticity of the flexed optical fiber to assist in retaining the end portion of the optical fiber in contact with the alignment groove

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

using an interference point to assist in forming a curved profile of the flexed fiber, the interference point being at least 1.5 millimeters from a mid-plane of the alignment device

Methodology Applied

Scientific EffectGeometric constraint: Geometry

Data Source

PatentEP3049839B1Optical connections system and methods for positioning an optical fiber within an alignment device

Publication Date: 2020.04.01 TE CONNECTIVITY CORP

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AI summary

A method for positioning an optical fiber having an end portion within an alignment groove of an alignment device includes orienting the optical fiber in the alignment groove of the alignment device; causing the optical fiber to elastically flex; using an interference point to assist in forming a curved profile of the flexed fiber, and using inherent elasticity of the flexed optical fiber to assist in retaining the end portion of the optical fiber in contact with the alignment groove. A connection system includes a connector, alignment device, and adapter, with an interference point on at least one of the connector, alignment device, or adapter.