Low-cost high-sensitivity strain and temperature sensing using graded-index multimode fibers

Area of Science:

• Photonics and Optical Sensing
• Fiber Optic Sensors
• Materials Science

Background:

• Fiber optic sensors offer advantages in harsh environments.
• Mode interference in multimode fibers is a known sensing principle.
• Cost-effective and high-sensitivity sensors are in demand for various applications.

Purpose of the Study:

• To develop a low-loss, low-cost, and high-sensitivity all-fiber sensor.
• To investigate strain and temperature sensing using mode interference in graded-index multimode fibers.
• To analyze the effect of fiber core diameter on sensor performance.

Main Methods:

• Utilized graded-index multimode fibers for sensor fabrication.
• Investigated sensor response to applied strain and temperature.
• Analyzed spectral shifts (blueshifts) in the optical signal.
• Compared sensor performance using fibers with different core diameters.

Main Results:

• Achieved high sensitivity to strain (18.6 pm/microstrain) and temperature (58.5 pm/°C).
• Observed blueshifts in the spectral peaks corresponding to strain and temperature changes.
• Demonstrated that smaller core diameter graded-index fibers exhibit larger strain-induced wavelength shifts.

Conclusions:

• The developed all-fiber sensor is effective for simultaneous strain and temperature measurement.
• Graded-index multimode fibers provide a viable platform for cost-effective, high-sensitivity optical sensing.
• Fiber core diameter is a critical parameter influencing strain sensitivity in this sensor configuration.