Spectroscopic measurements of species in flames (e.g.: H2, OH, NO, O2) are often the starting point of our combustion related investigations. Spectroscopic measurements allow to clarify if there is a background in a selected wavelength region like emission from other molecules. As an example, you can above see diagrams of the broad-band and narrow-band output of a XeF excimer laser as well as excitation and emission spectra of formaldehyde. 2D distributions of species (e.g. LIF, Raman, ...) are recorded by intensified CCD cameras if an appropriate excitation wavelength and a nearly background free wavelength region for detection are found. For excitation we have various lasers (e.g. advanced disk laser (ADL), excimer laser, Nd:YAG, CO2, quantum cascade, ...) available.

We perform measurements e.g. in industrial burners, in gas turbines and under micro-gravity conditions. The scheme below shows the excimer laser set-up in the drop tower of ZARM, university of Bremen, with the beam guiding system designed at IPHT. Meanwhile the excimer laser is replaced by an ADL system. The ADL system has the advantage to be located inside the drop capsule. A complex beam guiding system is no longer necessary.