We report on a spectroscopic technique named intracavity quartz-enhanced photoacoustic spectroscopy (I-QEPAS) employed for sensitive trace-gas detection in the mid-infrared spectral region. It is based on a combination of QEPAS with a buildup optical cavity. The sensor includes a distributed feedback quantum cascade laser emitting at 4.33 lm. We achieved a laser optical power buildup factor of 500, which corresponds to an intracavity laser power of 0.75 W. CO2 has been selected as the target molecule for the I-QEPAS demonstration. We achieved a detection sensitivity of 300 parts per trillion for 4 s integration time, corresponding to a noise equivalent absorption coefficient of 1.4108 cm1 and a normalized noise-equivalent absorption of 3.21010 W cm1 Hz1/2.
|Titolo:||Intracavity quartz-enhanced photoacoustic sensor|
|Data di pubblicazione:||2014|
|Digital Object Identifier (DOI):||10.1063/1.4867268|
|Appare nelle tipologie:||1.1 Articolo in rivista|