Abstract

A tunable external-cavity diode laser (ECDL) operating near 2.0 μm was used to perform absorption measurements of CO₂, H₂O, and N₂O in a heated static cell at various pressures (15 - 760 torr) and temperatures (294 K - 1460 K). The present work represents an extension of previous diode-laser absorption measurements of weaker vibrational overtones near 1.5 μm¹ and thus offers significantly higher measurement sensitivity. Absorption survey spectra of CO₂, H₂O, and N₂O in the spectral region between 4866 cm⁻¹ and 5118 cm⁻¹ were recorded, compared to calculations (based on the HITRAN96 and HITEMP databases), and used to select the optimum transitions for concentration measurements. Individual transitions (1-cm⁻¹ scans) were measured in order to determine line strength values and self broadening parameters.

© 1998 Optical Society of America