Refractive index insensitive temperature sensor based on specialty triple-clad fiber.

Area of Science:

• Photonics and Optical Sensing
• Materials Science
• Fiber Optics

Background:

• Developing accurate and reliable temperature sensors is crucial for various applications.
• Existing sensors may suffer from cross-sensitivity to environmental factors like refractive index (RI).
• Specialty optical fibers offer unique properties for advanced sensor designs.

Purpose of the Study:

• To propose and experimentally validate a refractive index (RI) insensitive temperature sensor.
• To leverage specialty triple-clad fiber (STCF) for enhanced sensing capabilities.
• To demonstrate real-time solution temperature monitoring with high accuracy.

Main Methods:

• Theoretical analysis using coupling mode theory to model STCF.
• Calculation of mode dispersion curves to understand cladding mode resonance.
• Experimental validation of the sensor's temperature sensitivity and RI insensitivity.

Main Results:

• The STCF sensor operates based on core-to-fluorine-doped silica cladding mode resonance.
• Achieved a high temperature sensitivity of 72.17 pm/°C within the 35°C–95°C range.
• Demonstrated excellent RI insensitivity across a broad range (1.3450 to 1.4607).

Conclusions:

• The proposed STCF sensor is effective for RI-insensitive temperature measurement.
• This technology is suitable for real-time solution temperature monitoring.
• The sensor's design offers a robust solution for challenging environments.