Tunable fiber laser based photoacoustic spectrometer for multi-gas analysis

A tunable fiber laser based multi-gas photoacoustic spectrometer has been developed. The spectrometer consists of a near infrared tunable fiber laser combining with a fiber amplifier, a first order longitudinal resonant photoacoustic cell and wavelength modulation mechanism. Simultaneous and continuous measurement of trace water vapor, acetylene, carbon dioxide, and carbon monoxide (H2O, C2H2, CO and CO2) in gas mixtures are achieved. The gas detection limits (signal-to-noise ratio = 1) of 70 ppm at 1524.57 nm for H2O, 2 ppb at 1529.18 nm for C2H2, 4 ppm at 1565.35 nm for CO and 4 ppm at 1572.66 nm for CO2 were demonstrated with the spectrometer.