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Updated: May 22, 2026
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Quantum cascade laser-based photoacoustic sensor for trace detection of formaldehyde gas
Angela Elia1, Cinzia Di Franco, Vincenzo Spagnolo
1Dipartimento Interateneo di Fisica "M. Merlin", Università and Politecnico of Bari, and Laboratorio Regionale CNR-INFM "LIT3", Bari, I-70126, Italy; E-Mails: cinzia.difranco@fisica.uniba.it (C.-D.F.); spagnolo@fisica.uniba.it (V.S.); lugara@fisica.uniba.it (P.-M.L.); scamarcio@fisica.uniba.it (G.S.).
Abstract:
We report on the development of a photoacoustic sensor for the detection of formaldehyde (CH(2)O) using a thermoelectrically cooled distributed-feedback quantum cascade laser operating in pulsed mode at 5.6 μm. A resonant photoacoustic cell, equipped with four electret microphones, is excited in its first longitudinal mode at 1,380 Hz. The absorption line at 1,778.9 cm(-1) is selected for CH(2)O detection. A detection limit of 150 parts per billion in volume in nitrogen is achieved using a 10 seconds time constant and 4 mW laser power. Measurements in ambient air will require water vapour filters.
