Cavity ringdown spectra of ammonia at 10 parts in 109 by volume (ppbv) and higher concentrations were recorded by use of a 16-mW continuous-wave quantum-casacde distributed-feedback laser at 8.5 μm whose wavelength was continuously temperature tuned over 15 nm. A sensitivity (noise-equivalent absorbance) of 3.4 × 10-9 cm-1 Hz-1/2 was achieved for ammonia in nitrogen at standard temperature and pressure, which corresponds to a detection limit of 0.25 ppbv.
|Original language||English (US)|
|Number of pages||3|
|State||Published - May 1 2000|
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics