Laser light with a defined colour or frequency is sent through the flame. The laser pulse has an effect of several megawatts, but the duration of the pulse is less than one millionth of a second. After the laser pulse has passed through the flame, the different species in the flame will emit weak light which will be detected by a very sensitive camera. This light pulse will contain a “fingerprint” from the specie that emitted the light pulse. In this way we are able to detect which species are present and where they occur in the flame. The method can be compared to spectroscopy with high spatial resolution. 

The trace species that occur in the flame are important for flame stability and formation of species that cause pollution. New knowledge of the processes inside flames is essential in our work to improve the mathematical models for combustion. On-going R&D work includes developing a new model for the formation of soot in flames.