Seminar Announcement: Simone Normani

Data pubblicazione: 2-nov-2015 13.32.13

Announcement

Monday, 26 October 2015, 11:00

Sala Grande Palazzina C via alla Cascata 56/C

"Multisite Excitation and Emission Properties of the Nd³⁺ and Lu³⁺ Doped CaF₂ Laser Crystals"

Simone Normani

Centre de recherche sur les Ions, les Matériaux et la Photonique (CIMAP), UMR 6252

CEA-CNRS-ENSICAEN, Université de Caen, 6 Blvd Maréchal Juin, 14050 Caen,

France

simone.normani@ensicaen.fr

Abstract

It was recently demonstrated that efficient and broadband laser emission was possible with Nd-doped CaF₂ and SrF₂ single crystals around 1.055 μm. Such laser emission, known as completely quenched because of cross-relaxation in the singly doped materials, increases spectacularly by co-doping with non-optically active ions like Y³⁺ or Lu³⁺. Broadband laser emission and ultra-short laser operation could be already demonstrated and large scale high peak power diode-pumped amplifiers can be anticipated. A deep investigation of both spectral and dynamical properties of CaF₂:Nd³⁺ crystals co-doped with various amounts of Lu³⁺ was performed via conventional spectroscopy techniques: the results suggest that an increase in Lu³⁺ concentration tends to increase the efficiency of Nd³⁺ transitions, interpreted as a consequence of cluster breaking by the buffer ions. By employing the parameters from previous data, time-resolved spectroscopy has been employed in order to isolate the different centres: different spectra resulted from these measurements, and linear combinations of the two have been seen to recover fairly faithfully the different emission spectra at different co-doping levels and excitation wavelengths.

Keywords: Laser crystals; Spectroscopy; CaF₂; Neodymium; Lutetium; Clustering.