Optical Waveguide Feedthrough with Gold Gasket Seal

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical waveguide feedthroughs face challenges in sealing optical fibers at high pressures and temperatures due to stress concentration and thermal expansion mismatches between glass fibers and sealing materials, leading to potential damage and contamination risks in harsh environments.

Innovation Solution

A cane-based optical waveguide feedthrough assembly with a conical glass plug and annular gold gasket, combined with a backup elastomeric seal, is designed to accommodate manufacturing tolerances and provide a durable, high-temperature, high-pressure seal, using a gold gasket to reduce stress and an elastomeric seal to ensure a reliable connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing glass is used to seal the optical fiber in an optical waveguide feedthrough, then the feedthrough can be hermetically sealed, but the stress concentration at the fiber-to-sealing glass interface causes the glass fiber to be susceptible to damage and breakage

Engineering Contradiction:

Improvehermetic seal integrityVSAvoidfiber strength at interface

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

A stress relief layer comprising a glass capillary and epoxy material is introduced as an intermediary between the optical fiber and the sealing glass. This stress relief layer acts as a buffer that absorbs and distributes thermal expansion stresses, preventing stress concentration at the fiber-to-sealing glass interface while maintaining hermetic seal integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The stress relief layer is pre-installed between the optical fiber and sealing glass before final assembly. This pre-positioned cushioning layer anticipates and absorbs thermal expansion stresses that would otherwise concentrate on the fragile fiber interface, preventing damage before it occurs during thermal cycling.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Ease of manufacture

If conventional sealing materials are used to seal the optical fiber, then the feedthrough can be manufactured, but the extremely low thermal expansion rate of fused silica compared to sealing materials creates excessive thermal stress at the interface

Engineering Contradiction:

Improvefeedthrough manufacturabilityVSAvoidthermal stress at interface

Core Design Contradiction:

Ease of manufactureVSStress or pressure

Solution Approach 1:

The stress relief layer changes the thermal expansion parameter of the sealing assembly by introducing materials with intermediate expansion characteristics between the fused silica fiber and the metal housing. This gradient approach reduces the abrupt thermal expansion mismatch, thereby decreasing thermal stress at the interface while maintaining manufacturability.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If the optical fiber is made flexible to accommodate installation, then the fiber can be routed easily, but the flexibility and small size make the fiber susceptible to damage and breakage

Engineering Contradiction:

Improvefiber routing flexibilityVSAvoidfiber resistance to damage

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The stress relief layer is pre-installed in the feedthrough assembly before the optical fiber is terminated. This cushioning layer is positioned in advance to catch and distribute any stresses that occur during fiber installation and operation, protecting the flexible but vulnerable fiber from damage while maintaining its routing flexibility.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 enables long-lasting operation in high-pressure and high-temperature environments, reducing the risk of fiber damage and contamination, while maintaining optical communication integrity through a robust and adaptable sealing mechanism.

Implementation Method 1

the control of thermal expansion rates becomes increasingly important in order to avoid failure of the feedthrough by excessive thermal stress at the interface layers between the various materials

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

The backup seal comprises an elastomeric annular member disposed between the glass plug and the housing

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS10606000B2Optical waveguide feedthrough assembly

Publication Date: 2020.03.31 WEATHERFORD TECHNOLOGY HOLDINGS LLC

AI summary

An optical waveguide feedthrough assembly passes at least one optical waveguide through a bulk head, a sensor wall, or other feedthrough member. The optical waveguide feedthrough assembly comprises a cane-based optical waveguide that forms a glass plug sealingly disposed in a feedthrough housing. For some embodiments, the optical waveguide includes a tapered surface biased against a seal seat formed in the housing. The feedthrough assembly can include an annular gold gasket member disposed between the tapered surface and the seal seat. The feedthrough assembly can further include a backup seal. The backup seal comprises an elastomeric annular member disposed between the glass plug and the housing. The backup seal may be energized by a fluid pressure in the housing. The feedthrough assembly is operable in high temperature and high pressure environments.