Chemical sensing with a pulsed 16 microns QC-DFB laser

Summary form only given. The development of quantum cascade (QC) lasers and especially single-frequency devices with distributed feedback (QC-DFB) provided an attractive new option for IR absorption spectroscopy. We report the first spectroscopic quantification of CO/sub 2/ and other species using a long-wavelength (/spl lambda/ = 16 /spl mu/m) thermoelectrically cooled pulsed QC-DFB laser. Long-wavelength QC lasers make accessible a spectral region where some large molecules, such as benzene exhibit a rotationally resolved structure, thus facilitating their detection and quantification. Different approaches to the laser frequency manipulation for spectroscopic data acquisition are discussed, and the achieved gas-sensing performance characteristics reported.