New laser crystals based on CaF2:Nd with double buffer ions for high energy lasers applications

Abstract

Within Neodymium doped laser crystals, the doping of fluorite-type single crystals reveals an unique possibility for broadband, high-energy, short-pulse laser amplification at 1µm, which makes these materials appealing to various high energy laser applications such as inertial confinement fusion (ICF), which require very high energy laser pulses with high repetition rates to achieve high efficiency. More precisely, Nd-doped CaF 2 crystals exhibit high thermal conductivity, and emission bands as wide as the state-of-the-art Nd-doped glasses currently employed in laser amplification for ICF for instance. In this work, a complete and detailed spectroscopic investigation of CaF 2 :Nd 3+ single crystals co-doped with different buffer ions, namely Gd, La, Ce, Y, Lu, Sc, was performed using several spectroscopy techniques including absorption, fluorescence, excitation spectra, time-resolved resolved emission and excitation spectroscopy and lifetime measurements. It was recently proven that co-doping with non-optically active "buffer" X ions like Y 3+ or Lu 3+ increases spectacularly Nd 3+ laser emission intensity by breaking quenched Nd-Nd clusters and forming instead Nd-X emitting clusters [1] [2] .