Düsseldorf 2007 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 43: Optische Messtechnik

Q 43.1: Vortrag

Mittwoch, 21. März 2007, 14:00–14:15, 5E

New design of Long-Path-Telescopes for atmospheric trace gas measurements based one fibre optic — •André Merten, Ulrich Platt, and Jens Tschritter — Institut für Umweltphysik, Im Neuenheimer Feld 229, 69126 Heidelberg

Long-Path-telescopes are commonly used for atmospheric trace gas measurement, especially in combination with the DOAS (Differential Optical Absorption Spectroscopy) analysis technique. Such an instrument combines the emitting and receiving telescope in one device with a double-Newton-style design and has a Xe-high pressure lamp as light source with a typical size from 1..2m. Therefore this instrument requires a high effort in planning and executing of field measurements and has also a limited signal-to-noise ratio. We developed a new set-up based on fibre optics, which is easier to handle, more stable in the alignment and also more efficient in the transmission and receiving of light. The use of a fibre coupled light source improves the spectral characteristics especially for light sources with a spatial variation of spectral features like high-pressure arc lamps and LEDs. This new design was tested successfully in field measurements. The construction of smaller generation of Long-Path-telescopes is now possible, which would extend the range of the application for this instrument. Together with new economic light source like the LED this instrument can be used for automatic monitoring of air pollutions.