title: Mid-infrared trace gas detection using continuous-wave difference frequency generation in periodically poled RbTiOAsO4.
abstract: A tunable mid-infrared continuous-wave (cw) spectroscopic source in the 3.4-4.5 micrometers region is reported, based on difference frequency generation (DFG) in a quasi-phase-matched periodically poled RbTiOAsO4 (PPRTA) crystal. DFG power levels of 10 microW were generated at approximately 4 micrometers in a 20-mm long PPRTA crystal by mixing two cw single-frequency Ti:Al2O3 lasers operating near 713 nm and 871 nm, respectively, using a laser pump power of 300 mW. A quasi-phase-matched infrared wavelength-tuning bandwidth (FWHM) of ~ 12 cm-1 and a temperature tuning rate of 1.02 cm-1/degree C were achieved. Experimental details regarding the feasibility of trace gas detection based on absorption spectroscopy of CO2 in ambient air using this DFG radiation source are also described.
authors.affiliation: MREID Universite du Littoral, Dunkerque, France. chen@univ-littoral.fr
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Mouret
authors.forename: D
authors.initials: D
authors.lastname: Boucher
authors.forename: F K
authors.initials: FK
authors.lastname: Tittel
mesh_terms: D000537:Aluminum Oxide; D001149:Arsenates; D002245:Carbon Dioxide / Q000032:analysis; D003460:Crystallization; D004784:Environmental Monitoring / Q000295:instrumentation*; D005740:Gases / Q000032:analysis*; D007834:Lasers; D016011:Normal Distribution; D055095:Optics and Photonics; D012413:Rubidium; D013055:Spectrophotometry, Infrared / Q000295:instrumentation; D014025:Titanium
chemical_list: D001149:Arsenates; D005740:Gases; D002245:Carbon Dioxide; D014025:Titanium; D000537:Aluminum Oxide; D012413:Rubidium