Combining a difference-frequency source with an off-axis high-finesse cavity for trace-gas monitoring around 3 mu m
Autori: Malara P., Maddaloni P., Gagliardi G., De Natale P.
Affiliazione autori: CNR – Istituto Nazionale di Ottica Applicata and European Laboratory for Non-Linear Spectroscopy (LENS), Comprensorio “A. Olivetti”, Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy
Abstract: High-sensitivity spectroscopy of methane around 3 mu m was carried out by means of a 5.5-mW cw difference-frequency generator in conjunction with a high finesse cavity in off-axis alignment. By cavity-output integration a minimum detectable absorption coefficient of 5.7(.)10(-9) cm(-1) Hz(-1/2) was achieved, which compares well with results already reported in the literature. Detection of methane in natural abundance was also performed in ambient air, for different values of total pressure, allowing direct concentration measurements via evaluation of the integrated absorbance of the spectra. In particular, at atmospheric pressure, a minimum detectable concentration of 850 parts per trillion by volume (pptv)(.)Hz(-1/2) was demonstrated. (c) 2006 Optical Society of America.
Giornale/Rivista: OPTICS EXPRESS
Volume: 14 (3) Da Pagina: 1304 A: 1313
Parole chiavi: Absorption; Atmospheric pressure; Pressure effects; Spectroscopic analysis; Trace analysis, Ambient air; Cavity-output integration; Difference-frequency generator; Integrated absorbance, MethaneDOI: 10.1364/OE.14.001304Citazioni: 30dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2021-09-19Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui