Wavelength modulated cavity enhanced absorption spectroscopy of water in the 1.37 microm region.
We describe the performance of a high-sensitivity wavelength modulated cavity enhanced infrared tunable diode laser absorption spectrometer for the detection of water vapor in the 1.37 mum region. The spectrometer can measure a fractional absorption of approximately 10(-5) for an absorption path length of a few kilometers. The instrument's sensitivity is more than sufficient to detect water isotopomers (H(2)(16)O, H(2)(18)O, HDO) at Martian atmospheric concentrations. The instrument is amenable to miniaturization, so a future compact, multiple-species version of the spectrometer will be highly suitable for in situ planetary exploration.
Vasudev
R
R
Jet Propulsion Laboratory, California Institute of Technology, MS 183-401, 4800 Oak Grove Drive, Pasadena, California 91109, USA. rvasudev@jpl.nasa.gov