Resonant optical transduction for photoacoustic detection

Thomas Lauwers (1) , Alain Glière (1) , Skandar Basrour (2)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 TIMA-CDSI - Circuits, Devices and System Integration

A highly sensitive optical transduction system suitable for photoacoustic trace gas detection is presented. The system includes a thin deformable hinged cantilever assembled on an optical fiber to form a Fabry-Perot cavity, whose length varies according to the acoustic pressure disturbance. Consequently, the optical power of the reflected light fluctuates at acoustic frequencies around the working point, which is stabilized to prevent from environmental drift of the interference fringes. The resonant mechanical structure proposed in this study shows a spectral response in good agreement with FEM simulation, good linearity and stability, with a noise equivalent pressure of 12 $\mu$Pa/√Hz.

Mots clés: Fiber-optic Fabry-Perot; acoustic sensor; hinged cantilever microphone; photoacoustic sensor; optical transduction

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Optique / photonique; Acoustique [physics.class-ph]; Micro et nanotechnologies/Microélectronique

Thomas Lauwers, Alain Glière, Skandar Basrour. Resonant optical transduction for photoacoustic detection. SPIE Photonics West 2020 - Optoelectronics, photonic materials and devices, Feb 2020, San Francisco, United States. ⟨cea-02481249⟩