High-sensitivity detection of hazardous SO_2 using 266 nm UV laser

摘要

Pulsed laser resonant photoacoustic spectroscopy was applied for detection of highly toxic SO_2 with 266 nm as the excitation source. An extra-cavity longitudinal resonant cell, was designed and fabricated to enhance the sensitivity of the system, which is capable of detecting the trace amount of SO_2. As a process of signal-to-noise ratio optimization, the parametric dependence of the PA signal was carried out and the sensitivity achieved with our system was as low as 4 ppb, which is considered to be a sufficient level for the detection of ambient SO_2 in the atmosphere. This study could be an antecedent for the design of a portable SO_2 sensor.