title: Portable fiber-coupled diode-laser-based sensor for multiple trace gas detection.
abstract: Tunable narrowband mid-infrared radiation from 3.25 to 4.4 micrometers is generated by a compact fiber-coupled, difference-frequency-based spectroscopic source. A 20-mW external cavity diode laser (with a tuning range from 814 to 870 nm) and a 50-mW distributed-Bragg-reflector diode-laser-seeded ytterbium-doped fiber amplifier operating at 1083 nm are difference-frequency mixed in a multi-grating, temperature-controlled periodically poled LiNbO3 crystal. A conversion efficiency of 0.44 mW/(W2cm) (corresponding to a power of approximately equal to 3 microW at 3.3 micrometers) represents the highest conversion efficiency reported for a portable device. Performance characteristics of such a sensor and its application to spectroscopic detection of CO2, N2O, H2CO, HCl, NO2, and CH4 will be reported in this work.
authors.affiliation: Rice Quantum Institute, Rice University, Houston, TX 77251-1892, USA. davelanc@rice.edu
authors.forename: D G
authors.initials: DG
authors.lastname: Lancaster
authors.forename: D
authors.initials: D
authors.lastname: Richter
authors.forename: F K
authors.initials: FK
authors.lastname: Tittel
mesh_terms: D002245:Carbon Dioxide; D004784:Environmental Monitoring / Q000295:instrumentation; D005336:Fiber Optic Technology; D005740:Gases / Q000032:analysis*; D006851:Hydrochloric Acid; D007834:Lasers; D008697:Methane; D009569:Nitric Oxide; D009609:Nitrous Oxide
chemical_list: D005740:Gases; D002245:Carbon Dioxide; D009569:Nitric Oxide; D009609:Nitrous Oxide; D008697:Methane; D006851:Hydrochloric Acid