Remote sensing of volcanic gases with a DFB-laser-based fiber spectrometer

We demonstrate monitoring of H2O and CO2 emitted in a volcanic area, using a spectrometer equipped with two distributed feedback (DFB) semiconductor d iode lasers. Each laser is resonant with a molecular species and is fiber-c oupled to allow remote operation of the spectrometer. Recordings of H2O and CO2 lines made at the Solfatara volcano, in southern Italy, are shown, and the application of such a spectrometer as a new tool for the continuous mo nitoring and surveillance of volcanoes is discussed.