Ultra-high sensitivity SPR temperature sensor based on a helical-core fiber

Area of Science:

• Optoelectronics
• Fiber optics sensing
• Plasmonics

Background:

• Optical fiber sensors offer remote and multiplexed sensing capabilities.
• Surface Plasmon Resonance (SPR) based sensors exhibit high sensitivity to refractive index changes.
• Accurate temperature sensing is crucial for various applications, including biomedical and healthcare.

Purpose of the Study:

• To propose and demonstrate a novel compact ultra-high sensitivity optical fiber temperature sensor.
• To investigate the influence of helical-core fiber (HCF) parameters on sensor performance.
• To explore the potential of the sensor for distributed sensing and its application in biomedical fields.

Main Methods:

• Fabrication of a D-type helical-core fiber coated with Au-film and polydimethylsiloxane (PDMS).
• Utilizing the surface plasmon resonance (SPR) phenomenon for temperature sensing.
• Experimental and theoretical analysis of the sensor's resonant wavelength and sensitivity based on HCF twisting pitch.

Main Results:

• The sensor's resonant wavelength and sensitivity are adjustable by altering the HCF twisting pitch.
• A maximum sensitivity of -19.56 nm/°C was achieved at room temperature with a 2.1 mm twist pitch.
• Sensitivity can be further enhanced by employing a shorter HCF pitch.

Conclusions:

• The proposed SPR optical fiber temperature sensor demonstrates adjustable sensitivity and ease of distributed sensing.
• The sensor's high refractive index sensitivity and PDMS thermo-optic coefficient contribute to its performance.
• Potential applications exist in biomedical, healthcare, and other fields requiring precise temperature monitoring.