Temperature effects in tuning fork enhanced interferometric photoacoustic spectroscopy

Area of Science:

• Optics and Photonics
• Spectroscopy
• Materials Science

Background:

• Trace gas detection is crucial for environmental monitoring and industrial applications.
• Photoacoustic spectroscopy (PAS) offers high sensitivity for gas sensing.
• Developing robust sensors that perform reliably across various temperatures is essential.

Purpose of the Study:

• To present temperature-dependent measurements of a compact fiber-coupled sensor for near-infrared trace gas detection.
• To investigate the impact of temperature on the sensor's performance, specifically the micro-tuning fork's resonance frequency and Q-factor.
• To demonstrate methane detection capabilities and validate a numerical model for resonator optimization.

Main Methods:

• Utilized tuning fork enhanced interferometric photoacoustic spectroscopy (TF-IPAS).
• Conducted temperature-dependent measurements from -41 °C to 107 °C.
• Integrated a silicon tuning fork with an acoustic off-beam resonator and employed COMSOL Multiphysics® for modeling.

Main Results:

• Characterized temperature effects on the micro-tuning fork's resonance frequency and Q-factor.
• Achieved a methane detection limit of S = (3.85 ± 0.01) ppm.
• Validated the numerical model for optimizing acoustic off-beam resonators.

Conclusions:

• The developed compact fiber-coupled sensor exhibits stable performance for trace gas detection over a broad temperature range.
• The sensor's design, incorporating a silicon tuning fork and acoustic off-beam resonator, enables highly sensitive methane detection.
• Numerical modeling is a valuable tool for optimizing photoacoustic resonator designs for enhanced gas sensing applications.