Gold-Coated Temperature Optical Fiber Sensor Based on a Mach-Zehnder Interferometer for Photovoltaic Monitoring

Area of Science:

• Photonics and Optical Sensing
• Materials Science for Sensors
• Interferometry

Background:

• Mach-Zehnder interferometers (MZIs) are sensitive to environmental changes.
• Tapered optical fibers offer enhanced evanescent field interaction for sensing.
• Gold coatings can modify the optical properties of fiber sensors.

Purpose of the Study:

• To develop and characterize a Mach-Zehnder interferometer based on tapered optical fiber for temperature sensing.
• To investigate the effect of gold deposition on the sensor's temperature sensitivity.
• To evaluate the performance of the sensor across different wavelength bands and temperature ranges.

Main Methods:

• Fabrication of two tapers on SMF-28e+ optical fiber using a fusion splicer.
• Coating the tapered optical structures with a 100 nm layer of gold.
• Characterization of the sensor's temperature sensitivity in O-, S-, C-, and L-bands from 0-70 °C.

Main Results:

• The gold-coated tapered fiber Mach-Zehnder interferometer demonstrated a high temperature sensitivity of 72 pm/°C.
• The sensor achieved a coefficient of determination (R²) of 0.9974, indicating excellent linearity.
• Low average transmission loss, not exceeding 7 dB, was observed during characterization.

Conclusions:

• Gold-coated tapered optical fiber Mach-Zehnder interferometers are effective for high-sensitivity temperature sensing.
• The gold layer enhances the temperature sensitivity of the fiber optic sensor.
• The developed sensor exhibits promising performance for practical temperature monitoring applications.