Ultrasensitive temperature sensor based on an isopropanol-sealed optical microfiber taper

Area of Science:

• Photonics
• Optical Sensors
• Material Science

Background:

• Optical microfiber tapers (OMTs) exhibit high sensitivity to refractive index changes.
• Developing precise and ultrasensitive temperature sensors is crucial for various scientific and industrial applications.

Purpose of the Study:

• To demonstrate an ultrasensitive temperature sensor utilizing an isopropanol-sealed OMT.
• To investigate the thermo-optic and thermal expansion effects contributing to temperature sensing.

Main Methods:

• Fabrication of an OMT sealed within a capillary using isopropanol.
• Characterization of the OMT's sensitivity to ambient refractive index.
• Experimental and theoretical analysis of temperature sensing performance.

Main Results:

• The OMT showed high refractive index sensitivity (18989 nm/RI unit).
• The sealed OMT functioned as an ultrasensitive temperature sensor with a maximum sensitivity of -3.88 nm/°C (20°C-50°C).
• Contributions of thermo-optic and thermal expansion effects were quantified.

Conclusions:

• An ultrasensitive temperature sensor based on an isopropanol-sealed OMT was successfully demonstrated.
• The sensor leverages the thermo-optic effect of isopropanol and thermal expansion for high temperature sensitivity.
• This technology offers potential for advanced thermal monitoring.