Univerzita Pardubice Fakulta chemicko- technologická

Univerzita Pardubice

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Publikace detail

In-depth Study of CaF2:Nd,Lu Crystals for High-Energy Lasers

Autoři: Normani Simone

Rok: 2018

Druh publikace: ostatní - přednáška nebo poster

Strana od-do: nestránkováno

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
eng	In-depth Study of CaF2:Nd,Lu Crystals for High-Energy Lasers	It was recently demonstrated that efficient and broadband laser emission was possible with Nd-doped CaF2 and SrF2 single crystals around 1.05 μm [1]. Such laser emission, known as completely quenched because of cross-relaxation in the singly doped fluorites [2], increases spectacularly by co-doping with non-optically active “buffer” ions like Y3+ or Lu3+ [3]. 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 particular, this work was carried out with the aim of obtaining an efficient amplifier for the 1053 nm laser line to enhance the Laser MégaJoule facility performances. Two main kinds of active Nd3+ centres appear in CaF2:Nd,Lu crystals, identified by their lifetimes and spectral features. Time-resolved spectroscopy allows estimating the cross sections and concentration of all the different clusters. Results show the gradual disappearance of inactive clusters, as a function of Lu3+ concentration, and the consecutive rise of the 1054 nm emission peak [4]. However, the thermal conductivity of CaF2:Nd,Lu crystals drops sensibly as the doping concentration increases. The knowledge on the evolution of both thermomechanical and spectroscopic properties allowed determining the appropriate composition range for an efficient 1.05 µm laser amplifier. Finally, the crystals amplification properties were tested, showing better gain properties than Nd:glasses. Laser action was achieved in both the CW and the mode-locked regimes, and output pulses shorter than 1 ps were obtained. These results demonstrate the viability of CaF2:Nd,Lu as a short-pulse laser gain medium and open the way for the improvement of high-energy laser amplifiers.	CaF2:Nd,Lu; LMJ; high-energy laser; spectroscopy; clustering; thermal lens