Institut für Physikalische Chemie
Lehrstuhl für Molekülspektroskopie und Nanosysteme 
Professor Karl Kleinermanns Research Group 

High Resolution Laser Induced Fluorescence (HRLIF)

HRLIF utilizes the very high resolution of a single mode ring dye laser in combination with strongly collimated molecular beams to obtain rotationally resolved spectra of clusters of different size. The experimental setup differs considerably from the above techniques, because it utilizes continuous wave (cw) laser radiation and, for sake of reasonable duty cycles, has therefore to be performed with continuous molecular beams. This requires a great deal of experimental effort like differential pumping in several stages, very small nozzle diameters and large pumping capacities. Due to the smaller photon flux second harmonic generation of cw-laser radiation is not as straightforward as frequency doubling of pulsed lasers. It has to be performed either in the laser cavity or in an actively stabilized external cavity for resonance enhancement of the nonlinear process.

Rotational constants obtained upon investigation of the electronic origin are used to deduce cluster structures both in the electronic ground and excited state. Broadening of rotational lines or their tunneling splitting in periodic potentials may lead to a deeper insight into intramolecular dynamical processes. Rotationally resolved spectra of intermolecular vibronic bands yield vibrationally averaged rotational constants which, in combination with the techniques described above, may help to identify the nature of this vibration. An inherent disadvantage of HRLIF is the lack of mass resolution as in any fluorescence technique. It therefore depends on preliminary investigations like SHB to reveal the affiliation of a vibronic band to a certain cluster species.

To the HRLIF Research Group Homepage

Selected Publications:

Giel Berden, Leo Meerts and Michael Schmitt, Karl Kleinermanns, high resolution UV spectroscopy of Phenol and the hydrogen bonded Phenol/water cluster, J. Chem. Phys. 104 (1996) 972

To the PC I Homepage
To the Research Group
To the HHU Homepage
If you have any comments, suggestions or remarks, please EMail to: pc1@uni-duesseldorf.de
last changed: 05.01.2004 Michael Nispel
number of accesses to this page: