Correction of Excite-and-Probe Spectra with Respect to Variations of Pump Pulse Energy

Abstract

Excite-and-probe beam spectra can be applied to investigate the nature of excited molecular states as well as to determine kinetic parameters of these molecules [1]. Often many kinetic processes occur simultaneously and bring about a complex behaviour of the spectra. Furthermore the separation of the contributions of different transitions to the probe beam absorption can be obstructed by a spectral overlap of bands with different kinetics. In most of the experimental arrangements the probe beam transmission is not measured simultaneously for all wavelengths and delay times, and, besides, it is often necessary to repeat the transmission measurements to enlarge accuracy. Because the probe beam transmission is dependent on the pump beam parameters it is advantageous to correct the results with respect to pump pulse variations, if a sufficiently high stabilization of these parameters is not possible. Variations of the primary laser pulses are often enlarged by nonlinear optical processes applied to change the excitation frequency.