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Q: Fachverband Quantenoptik und Photonik
Q 54: Laser Applications: Optical Measurement Technology I
Q 54.8: Vortrag
Donnerstag, 11. März 2010, 15:45–16:00, F 342
Very sensitive in situ gas analysis of combustion processes with an Er3+-doped fiber laser — •Benjamin Löden1, Svetlana Kuznetsova1, Anatoly Goldmann2, Sergej Cheskis2, Klaus Sengstock1, and Valeri Baev1 — 1Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg — 2School of Chemistry, Tel-Aviv University, Tel Aviv 69978, Israel
Intracavity absorption spectroscopy with a broadband Er3+-doped fiber laser is applied for the measurements of several molecular species revealing quantitative information about the gas concentration, temperature and chemical reactions in flames. The spectral range of the measurements extends from 6200 cm−1 to 6550 cm−1 with the proper choice of the fiber length and by moving an intracavity lens. With a pulsed laser applied in this experiment the sensitivity corresponds to an effective absorption path length of 3 km and does not depend on the broadband cavity losses. Absorption spectra of various molecules such as CO2, CO, H2O, H2S, C2H2 and OH were recorded separately in the cell and/or in low pressure methane and propane flames. The presented measurements demonstrate simultaneous in situ detection of three molecular products of chemical reactions at different flame locations. The variation of the relative strengths of OH absorption lines with the temperature enables the estimation of the local flame temperature. The presented technique can be applied for various diagnostic purposes, such as environmental, combustion and plasma research, medical applications and measurements of stable isotope ratio.