Abstract

A nitrogen dioxide (NO₂) sensor based on conventional photoacoustic spectroscopy and a 3.5 W multimode violet-blue diode laser was designed and demonstrated. The photoacoustic cell uses a construction with differential resonators to reduce the impact from ambient acoustic noise. A minimum detection limit of ~ 54 pptv was obtained with a 1 s integration time, corresponding to a 1 σ noise equivalent absorption coefficient of 1.583 × 10⁻⁹ cm⁻¹ W/Hz^1/2. Such a sensor system will allow continuous monitoring of atmospheric NO₂ concentration.

© 2017 Optical Society of America