A Sensitivity-Enhanced Sub-Zero Temperature Sensor Based on the Mach-Zehnder Interferometer Coated with Organic...

Area of Science:

• Fiber optics
• Sensor technology
• Materials science

Background:

• Accurate sub-zero temperature monitoring is crucial in various scientific and industrial fields.
• Existing sensors may lack the required sensitivity or robustness for extreme conditions.

Purpose of the Study:

• To develop and characterize a high-sensitivity fiber optic sensor for sub-zero temperature detection.
• To investigate the impact of sensor fabrication parameters on sub-zero temperature sensitivity.

Main Methods:

• Fabrication of a single-mode-multimode-single-mode (SMS) fiber structure using CO2 laser polishing.
• Coating the SMS structure with a mixed film of hydroxyl-terminated siloxane and methyl MQ silicone resin.
• Experimental evaluation of sub-zero temperature sensitivity with varying numbers of polished facets.

Main Results:

• Sub-zero temperature sensitivity increased from 0.73 nm/K to 2.15 nm/K for sensors with one to four polished facets.
• The sensor demonstrated high sensitivity in the temperature range of 223 K to 273 K.
• The organic silicone film effectively functioned as a sub-zero-sensitive layer.

Conclusions:

• The proposed Mach-Zehnder interferometer-based fiber optic sensor offers high sensitivity for sub-zero temperature measurement.
• The sensor exhibits advantages such as a compact structure, high sensitivity, and low cost.
• Potential applications include biomedicine, aerospace, and energy sectors.