Journal de physique

Double excitation of Nd3+ pairs in LaF3 by two step and double quantum processes

R. Buisson, J.Q. Liu, Jean‐Claude Vial

Published Jan 1, 1984• 22 citations

Abstract

Using the energy level shift induced by a Nd3+ ion on a neighbour ion, the selective excitation of a class of (Nd, Nd) pairs is possible in weakly doped samples with a spectrally narrow laser. The observation of an anti-Stokes fluorescence shows that a pair can absorb two photons. From experiments with a magnetic field, it is shown that using a single laser, the double excitation of moderatly coupled pairs is essentially induced by a double quantum process by which two photons are simultaneously absorbed. The strongly coupled pairs, on the contrary, can only be doubly excited by two lasers of different frequencies. Orders of magnitude of the coupling strength between the two ions are deduced from the difference between these frequencies.

DOI: 10.1051/jphys:019840045090153300

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