Rare-earth doped halide crystals for laser applications: recent advances and future trends P. Camy, J.L. Doualan, A. Benayad, V. Ménard, A. Ferrier, M. Velàzquez, R. Moncorgé Centre de Recherche sur les Ions, les Matériaux et la Photonique (CIMAP) UMR 6252 CEA-CNRS-ENSICaen, Université de Caen, 14050 Caen, France * Corresponding author: richard.moncorge@ensicaen.fr ABSTRACT The presentation will give the state of the art and the results of the last advances obtained in the growth, the characterization and the implementation of three kinds of rare-earth doped halide laser crystals: Pr 3+ doped fluorides, Yb 3+ doped CaF 2 and its isotypes, and Er 3+ and Pr 3+ doped chloride and bromide KPb 2 Cl 5 and Tl 3 PbBr 5 . Keywords: Rare-earth, crystal, laser 1. INTRODUCTION While fiber, semiconductor and nonlinear optical materials now offer an increasing number of possibilities for various types of applications, rare-earth doped crystals, eventually used in association with the latter, still remain the standard in most of the efficient and high power/high energy solid state laser sources, and, among these, some particular rare-earth doped halides have very specific properties and advantages. Three kinds of rare-earth doped halide materials, either already confirmed or being developed for specific laser systems, have been studied in our laboratory and will be presented in this communication: (i) Pr 3+ doped fluorides in the form of bulk and thin-films for the RGB and the quantum computing laser applications, (ii) Yb 3+ doped CaF 2 and its isotypes for the production and the amplification of short-pulse and high peak power, high repetition rate laser systems, (iii) Er 3+ and Pr 3+ doped non-hygroscopic lead chlorides and bromides for the production of mid-infrared laser sources. Pr 3+ doped fluorides such as KY 3 F 10 indeed have been recently proved to be the most suitable materials to built both efficient and compact RGB diode-pumped laser sources (using the recently developed GaN semiconductor blue laser diodes) and among them, those able to emit at some specific wavelengths in the orange domain are really attractive to replace the cumbersome dye lasers presently used for the quantum computing experiments. On the other hand, the apparent simplicity of the Yb 3+ doped CaF 2 system and its isotypes, the quality and the size of the crystals which can be obtained and their exceptional thermo-mechanical and optical properties have made of these materials really competitive materials for the high peak power and high repetition rate laser chains which are presently developed in many places around the world. Er 3+ and Pr 3+ doped lead chlorides such as KPb 2 Cl 5 and Tl 3 PbBr 5 are being studied, on their side, because of their non-hygroscopicity and their very low phonon energies which allow emission transitions with excellent quantum efficiencies far in the mid-infrared and which thus offer the possibility to built rather simple diode-pumped and broadly tunable laser sources in a spectral domain (above 4 μm) which is hardly accessible to other systems. 2. PRASEODYNIUM DOPED FLUORIDES Praseodymium has been more particularly selected for the RGB [1-3] and quantum computing laser applications [4-6] mentioned because, as shown in the Fig. 1(left side), it is the only rare-earth ion offering the possibility to emit laser radiations both in the red, in the orange, green and blue regions [2,7,8] from the unique set of 3 P 0,1 thermalized energy levels. Moreover this emitting ion is almost essentially considered in fluorides (fluoride crystals and glasses), because of Invited Paper Optical Components and Materials VI, edited by Shibin Jiang, Michel J. F. Digonnet, John W. Glesener, J. Christopher Dries, Proc. of SPIE Vol. 7212, 721206 © 2009 SPIE · CCC code: 0277-786X/09/$18 · doi: 10.1117/12.816052 Proc. of SPIE Vol. 7212 721206-1