Multiphoton excitation and emission from europium ions in aqueous solution.
Simultaneous emission induced by one- and two-photon absorption from the charge-transfer band from aqueous solutions of europium perchlorate pumped by a repetitively pulsed nitrogen laser have been detected. These processes were verified both through the measured fluorescence intensity as a function of the laser flux and from a qualitative analysis of the two overlapping characteristic broad emission spectra, which are dependent on the excitation wavelength. A theoretical fit could be made to the laser-power-dependence data, which gave a two-photon absorption coefficient of approximately 4 x 10(-49) cm(4) sec/photon-molecule for this system.
Giuliani
J F
JF