Seminar Announcement: Simone Normani

Data pubblicazione: 3-nov-2017 13.10.44

Announcement

Tuesday, 31 October 2017, 15:00

Sala Grande Palazzina B via alla Cascata 56/C

"CaF₂:Nd,Lu Crystals for High-Energy Lasers"

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 1.05 μm. Such laser emission, known as completely quenched because of cross-relaxation in the singly doped fluorites, increases spectacularly by co-doping with non-optically active “buffer” ions like Y³⁺ or Lu³⁺. Broadband laser emission and ultra-short laser operation are therefore possible. The material is particularly appealing for large scale high peak power diode-pumped amplifiers. In the framework of the LASCAN project for the improvement of the Laser MégaJoule and Petawatt Aquitaine Laser, a deep investigation of the spectral properties of CaF₂:Nd³⁺ crystals co-doped with various amounts of Lu³⁺ was performed. The cluster breaking effect of Lu³⁺ codoping has as a side-effect the appearance of two different contributions, identified as two different active sites, which is in agreement with recent observations. In this work, we detail the different centres’ spectroscopic properties and operational parameters for laser applications, their evolution as the lutetium concentration increases, and the thermomechanical properties of said samples. A preliminary investigation on the amplification properties and laser operation of said materials is performed as well.