Hollow-Core Fiber-Tip Interferometric High-Temperature Sensor Operating at 1100 °C with High Linearity

Area of Science:

• Photonics and Optical Sensing
• Materials Science for High-Temperature Applications
• Interferometry

Background:

• Conventional single-mode fiber sensors struggle with linearity and stability at high temperatures.
• High-temperature measurements often require isothermal annealing to mitigate thermal hysteresis and residual stress.
• Existing methods for fiber-optic temperature sensing are limited in their operational range or require costly pre-treatments.

Purpose of the Study:

• To propose and demonstrate an annealing-free fiber-optic high-temperature sensor.
• To achieve accurate and stable temperature measurements up to 1100 °C without pre-annealing.
• To develop a cost-effective sensor suitable for industrial applications.

Main Methods:

• Fabrication of a diaphragm-free hollow-core fiber (HCF) Fabry-Perot interferometer (FPI).
• Experimental characterization of the FPI sensor's performance in the 100-1100 °C temperature range.
• Evaluation of thermal stability and linearity without high-temperature annealing procedures.

Main Results:

• The proposed HCF-FPI sensor demonstrated excellent thermal stability and linearity (R² > 0.99) from 100 °C to 1100 °C.
• The sensor operates effectively without the need for high-temperature isothermal annealing.
• The sensor preparation is simple, contributing to reduced production costs.

Conclusions:

• An annealing-free fiber-optic sensor based on HCF-FPI is successfully demonstrated for high-temperature measurements.
• The sensor eliminates the need for costly and time-consuming annealing processes.
• The simplicity and cost-effectiveness make it a promising candidate for mass production and industrial deployment.