Sapphire-fiber-based white-light interferometric sensor for high-temperature measurements

Area of Science:

• Materials Science
• Optical Engineering
• Sensor Technology

Background:

• Accurate high-temperature measurement is critical in many industrial and scientific applications.
• Existing fiber-optic sensors may face limitations in extreme temperature environments.
• Sapphire's unique optical and thermal properties make it a promising material for high-temperature sensing.

Purpose of the Study:

• To develop and demonstrate a robust fiber-optic temperature sensor capable of operating at extreme temperatures.
• To utilize the thermal dependence of optical properties in sapphire for temperature sensing.
• To evaluate the performance, accuracy, and reproducibility of the developed sensor.

Main Methods:

• A fiber-optic sensor was designed using a single-crystal sapphire fiber as the light guide and a sapphire wafer as the sensing element.
• White-light interferometry was employed to measure the thermal dependence of the sapphire wafer's optical thickness.
• Digital signal processing techniques were applied for spectral analysis of the sensor's output.

Main Results:

• The prototype sensor was successfully tested at temperatures up to 1600 degrees C.
• Excellent reproducibility was demonstrated across repeated high-temperature measurements.
• An accuracy of +/- 0.2% of full scale was achieved.
• The sensor exhibited a simple, small, and flexible design.

Conclusions:

• The developed sapphire fiber-optic sensor is a viable solution for high-temperature measurements.
• The sensor's design offers advantages in terms of batch fabrication and ease of calibration.
• This technology has significant potential for applications requiring reliable high-temperature sensing.