Abstract
We report a novel photoacoustic spectrometer for trace gas sensing of benzene. A quantum cascade laser emitting at the wavelength 14.8 µm is used as the light source in the spectroscopic detection. This wavelength region contains the strongest vibrational band of ben-zene, which is free of spectral overlap from common trace gases, making it a strong candidate for sensitive benzene detection. Cantilever-enhanced photoacoustic spectroscopy is used for detection. This simple and robust measurement setup can reach a benzene detection limit below 1 ppb.