RESUMEN
We report the development of a novel laser spectrometer for high-sensitivity detection of methane and nitrous oxide. The system relies on a quantum-cascade laser source emitting wavelength of around 8.06 microm, where strong fundamental absorption bands occur for the considered species and their isotopomers. The detection technique is based on audio-frequency and radio-frequency modulation of laser radiation. First experimental tests have been performed to estimate the achievable detection limits and the signal reproducibility levels in view of possible measurements of (13)C/(12)C, (18)O/(16)O, (17)O/(16)O and (15)N/(14)N isotope ratios.
Asunto(s)
Isótopos de Carbono/análisis , Monitoreo del Ambiente/métodos , Metano/análisis , Isótopos de Nitrógeno/análisis , Óxido Nitroso/análisis , Isótopos de Oxígeno/análisis , Espectrofotometría Infrarroja/métodos , Monitoreo del Ambiente/instrumentación , Rayos Láser , Metano/química , Óxido Nitroso/química , Espectrofotometría Infrarroja/instrumentaciónRESUMEN
We demonstrate the generation of cw tunable far-infrared radiation by mixing a quantum cascade laser and a CO>(2) laser in a W-Ni metal-insulator-metal diode. The first known spectroscopic application to the recording of an H(79)Br transition near 4.47 THz is reported.