Simple feed-through for coupling optical fibres into high pressure and temperature systems

TL;DR

This paper presents a practical, cost-effective method for coupling optical fibers into high-pressure and high-temperature environments, demonstrating reliable sealing up to 500 bar and 180°C.

Contribution

It introduces a simple, tested system using standard components and various ferrule materials for optical fiber feed-through in extreme conditions.

Findings

Successful sealing during multiple pressure and temperature cycles

Compatibility of standard Swagelok connectors with high-pressure, high-temperature environments

Effective use of PEEK capillary tubes as feed-throughs

Abstract

A best practice guide for assembling and testing a simple and inexpensive system feeding an optical fibre into a high pressure and temperature environment is presented. A standard Swagelok type connector is tested together with different ferrule materials and a PEEK capillary tube as feed-through. The system proofed to seal an optical fibre during several pressure and temperature cycling experiments up to 500 bar and 180{\deg}C.