Pulsed, broadly tuneable, photoacoustic study of rare-earth doped LiNbO3

Rare-earth (RE) doped solids are widely used as optical emitters from the n ear infrared to the ultraviolet range. A key measurement for such applicati ons, the luminescent quantum efficiency, quantifies the comparison between radiative and non-radiative probabilities, which can be evaluated from lumi nescence and photoacoustic measurements, respectively. The photoacoustic an d luminescence excitation signals can be obtained either under pulsed dual- wavelength excitation or CW tuneable excitation, by using Nd-YAG and Ti:Sap phire lasers. In the present work, we demonstrate the use of pulsed, broadl y tuneable, excitation using an optical parametric oscillator (OPO), extend ing the spectral range of application covering practically all the near inf rared to the ultraviolet range, and accessing any RE emitting level. The pr ocedure is applied to RE-doped lithium niobate (LiNbO3), a material of grea t interest far optoelectronic applications. (C) 2001 Elsevier Science B.V. All rights reserved.