Two-photon spectrometer based on flashlamp-pumped dye lasers

Abstract
We describe here a two-photon spectrometer that utilizes two independently tuned, flashlamp-pumped dye lasers, and the associated detection electronics for the determination of the temporal profile of the two lasers (FWHM≈200 ns) and the fluorescence pulse following two-photon excitation. This spectrometer allows for proper normalization of the observed signal to the laser power. Procedure for the extraction of relative cross sections for two-photon absorption is described, and a spectrum obtained for a solution of naphthalene in benzene is presented.