TUNABLE DIODE-LASER ABSORPTION-SPECTROSCOPY OF CARBON-MONOXIDE AROUND2.35 MU-M

Novel GaInSbAs/GaSb multiple-quantum-well lasers operating near room t emperature have been successfully used for tunable diode laser absorpt ion spectroscopy in the vicinity of 2.35 mu m. Continuous current tuni ng over a more than 150-GHz frequency range has been realized. Direct absorption measurements have been carried out on the R9, R10, R11, and R12 lines of carbon monoxide. Traces of carbon monoxide at the level of 0.3 part in 10(6) in volume at 100 Torr could be detected by the lo w frequency wavelength-modulation technique and an astigmatic multipas s cell. These results show a potential use of these diode lasers in po rtable low-cost trace-pollutant sensors. (C) 1998 Optical Society of A merica. OCIS codes: 300.1030, 300.6340, 300.6380, 300.6260, 230.5590, 280.3420.