Ultra-sensitive temperature and pressure sensor based on PDMS-based FPI and Vernier effect

Area of Science:

• Optoelectronics
• Sensor Technology
• Materials Science

Background:

• Fabry-Perot interferometers (FPIs) are widely used for sensing applications.
• Existing FPI sensors face limitations in sensitivity and cross-sensitivity to environmental factors.
• Developing enhanced sensing mechanisms is crucial for accurate real-time monitoring.

Purpose of the Study:

• To design and demonstrate an ultra-sensitive sensor for simultaneous temperature and pressure measurement.
• To investigate the Vernier effect in a cascaded FPI system for enhanced sensing performance.
• To utilize a polydimethylsiloxane (PDMS)-based FPI and a stable reference FPI.

Main Methods:

• Fabrication of a sensing FPI using polydimethylsiloxane (PDMS).
• Integration of a closed capillary-based FPI as a reference cavity.
• Cascading the two FPIs in series to create a composite sensor with a spectral envelope.
• Experimental characterization of the sensor's response to temperature and pressure variations.

Main Results:

• The cascaded FPI sensor exhibited a clear spectral envelope.
• Achieved ultra-high temperature sensitivity of 16.51 nm/°C.
• Demonstrated remarkable pressure sensitivity of 100.18 nm/MPa.
• Observed a significant Vernier effect, with sensitivities 25.4 and 21.6 times higher than the individual sensing FPI.

Conclusions:

• The proposed cascaded FPI sensor offers significantly enhanced temperature and pressure sensing capabilities.
• The Vernier effect in the cascaded FPI system is key to achieving ultra-high sensitivity.
• This sensor design presents a promising platform for advanced environmental monitoring and instrumentation.