Wavelength modulation technique-based photoacoustic spectroscopy for multipoint gas sensing.

A multipoint gas sensing scheme based on photoacoustic spectroscopy was proposed. Multiple photoacoustic spectroscopy (PAS) gas cells (resonant frequency f0=5.0  kHz) were connected in series for the multipoint gas sensing with wavelength modulation technique. The PAS signal was excited by modulating the tunable distributed feedback laser diode wavelength… CONTINUE READING