Photoacoustic spectroscopy detection based on complementary interdigital cantilever enhanced Fabry-Perot acoustic...

Area of Science:

• Optoelectronics
• Acoustic Sensing
• Spectroscopy

Background:

• Photoacoustic spectroscopy (PAS) is vital for trace gas detection.
• Improving acoustic sensor sensitivity is key to enhancing PAS performance.
• Existing sensors face limitations in detecting low concentrations.

Purpose of the Study:

• To develop a novel fiber optic acoustic sensor (FOAS) for improved PAS.
• To enhance sound pressure detection capabilities for trace gas analysis.
• To investigate the performance of a complementary interdigital (CID) cantilever Fabry-Perot (F-P) sensor.

Main Methods:

• Fabrication of a CID cantilever Fabry-Perot fiber optic acoustic sensor.
• Operation of the CID cantilever at its resonance frequency (1010 Hz).
• Testing the sensor's sensitivity, signal-to-noise ratio, and minimum detectable pressure.

Main Results:

• The CID cantilever FOAS achieved a high sensitivity of 923.7 nm/Pa.
• A signal-to-noise ratio of 72.2 dB and minimum detectable pressure of 16.4 μPa/Hz^1/2 were recorded.
• PAS sensitivity to C₂H₂ gas was 3.02 pm/ppm, with a detection limit of 30.17 ppb.

Conclusions:

• The developed CID cantilever FOAS significantly enhances acoustic sensing for PAS.
• Resonant frequency matching and signal amplification improve trace gas detection sensitivity.
• This technology offers a promising solution for high-sensitivity gas analysis.