Loss-compensated photoelastic fiber optic pressure sensor

Area of Science:

• Optoelectronics
• Sensor Technology
• Materials Science

Background:

• Fiber optic sensors offer advantages in harsh environments.
• The photoelastic effect is a known principle for stress-optic sensing.
• Existing fiber optic pressure sensors face challenges with down-lead sensitivity and environmental fluctuations.

Purpose of the Study:

• To develop a robust fiber optic pressure sensor.
• To achieve down-lead insensitivity in a fiber optic pressure sensor.
• To enhance the stability and accuracy of optical pressure sensing.

Main Methods:

• A fiber optic pressure sensor was constructed using the photoelastic effect.
• A four-port polariscope setup was employed.
• A balanced bridge referencing technique was utilized to mitigate down-lead effects.

Main Results:

• The sensor demonstrated excellent insensitivity to source intensity fluctuations.
• The design effectively compensated for mode-dependent and mode-independent damping changes in the down leads.
• The sensor achieved a linearity of +/-0.1% and temperature stability of +/-1% over a 6 bar range (0-60°C).

Conclusions:

• The developed fiber optic pressure sensor effectively overcomes down-lead sensitivity issues.
• The balanced bridge referencing technique significantly improves sensor reliability.
• The sensor's high linearity and temperature stability make it suitable for precise pressure measurements.