(1) Rice Quantum Institute, Rice University, Houston, TX 77251-1892, USA;(2) Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
Abstract:
A novel continuous-wave mid-infrared distributed feedback interband cascade laser was utilized to detect and quantify formaldehyde (H2CO) using quartz-enhanced photoacoustic spectroscopy. The laser was operated at liquid-nitrogen temperatures and provided single-mode output powers of up to 12 mW at 3.53 m (2832.5 cm-1). The noise equivalent (1) detection sensitivity of the sensor was measured to be 2.2×10-8 cm-1W(Hz)-1/2 for H2CO in ambient air, which corresponds to a detection limit of 0.6 parts in 106 by volume (ppmv) for a 10 s sensor time constant and 3.4 mW laser power delivered to the sensor module. PACS 42.62.Fi; 72.50.+b