Portable broadband photoacoustic spectroscopy for trace gas detection by quantum cascade laser arrays
Abstract
We report a portable broadband photoacoustic spectroscopic system for trace gas detection using distributed feedback quantum cascade laser arrays. By sequentially firing 128 lasers, our system acquires a photoacoustic spectrum covering 565 c m − 1 ( 935 − 1500 c m − 1 ) with a normalized-noise-equivalent-absorption coefficient of 2.5 × 10 − 9 c m − 1 W H z − 1 / 2 . The firing sequence that determines when and which laser to activate is programmable, which enables frequency-multiplexing excitation. For demonstration, 12 lasers are modulated simultaneously at distinct frequencies, and a photoacoustic spectrum is acquired within 13 ms. The compactness ( 28 c m × 17 c m × 13 c m , 3.5 kg) and low power consumption enable convenient installation for on-site monitoring.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 09, 2020
- Source ID
- 10.1364/ol.395202
Entities
People
- Chien-sheng Liao
- Christian Pfluegl
- Daryoosh Vakhshoori
- Fred Huettig
- Masud Azimi
- Romain Blanchard
Organizations
- United States Army Combat Capabilities Development Command