Monolithic Double Resonator for Quartz Enhanced Photoacoustic Spectroscopy

Abstract

A new approach for Quartz Enhanced Photoacoustic Spectroscopy is presented, based on an acoustic excitation from the outside of the prongs of a quartz tuning fork, to increase the sensitivity of the sensor. For this purpose, we introduce a monolithic acoustic double-resonator (double-mR) in a T-shape configuration, using 3D printing. It was modelized and experimentally characterized using a 1392 nm distributed feedback laser diode, targeting a water vapor absorption line. The setup showed a two-factor enhancement of the signal, compared to a classical off-beam QEPAS approach and confirmed the strong interest of photolithographic printing techniques for acoustic developments.

Keywords

• photoacoustics
• infrared
• laser
• sensing
• QEPAS