High-Sensitivity Curvature Fiber Sensor Based on Miniature Two-Path Mach-Zehnder Interferometer

Area of Science:

• Optoelectronics
• Fiber Optic Sensors
• Interferometry

Background:

• Mach-Zehnder interferometers (MZIs) are widely used in sensing applications.
• Traditional MZI fabrication can be complex and costly.
• Developing compact and highly sensitive fiber optic sensors remains a key research area.

Purpose of the Study:

• To introduce a novel miniature two-path Mach-Zehnder interferometer (MTP-MZI) fiber sensor.
• To demonstrate high sensitivity for curvature measurement.
• To investigate the sensor's performance in temperature sensing and address cross-sensitivity.

Main Methods:

• Fabrication of the MTP-MZI sensor by coupling and fusing multimode fiber (MMF) with single-mode fiber (SMF) using arc fusion technology (AFT).
• Experimental evaluation of the sensor's response to varying curvature.
• Experimental evaluation of the sensor's response to varying temperature.

Main Results:

• The MTP-MZI sensor achieved a maximum curvature sensitivity of -96.70 dB/m^-1 in the range of 0.0418 m^-1 to 0.0888 m^-1.
• The sensor exhibited a maximum temperature sensitivity of 212 pm/°C in the range of 30 °C to 70 °C.
• The developed sensor demonstrated low temperature cross-sensitivity.

Conclusions:

• The miniature MTP-MZI fiber sensor offers an innovative and cost-effective solution for high-sensitivity curvature sensing.
• The sensor's low temperature sensitivity effectively mitigates cross-sensitivity issues.
• The MTP-MZI provides a new platform for developing multidimensional and multiparameter fiber optic sensing systems.