Fiber-Coupled Ozone Sensor Based on Tuning Fork-Enhanced Interferometric Photoacoustic Spectroscopy

In this paper, a completely fiber-coupled ozone sensor based on tuning fork (TF)-enhanced photoacoustic spectroscopy is presented. Crystalline silicon micro-TFs are processed and characterized. Their photoacoustically induced motion is monitored by a compact intensity interferometer. An acoustic microresonator for this new type of TFs is optimized. A frequency-doubled Nd:YAG laser is used as an excitation source. The sensor performance is assessed by calibration measurements. It reaches a detection limit of S = 2.13 ppm ± 0.02 ppm and a noise-equivalent absorption sensitivity of D = (1.27 × 10
^-9
± 1.2 × 10
^-11
) cm
^-1
W(Hz)
^-1/2
.