Matias Velazquez

Potential of the Eu:LYB crystal as a laser material for DPSS lasers emitting at 613 nm

We show the spectroscopic properties of a new potential laser crystal in the visible range. The Eu-doped borate compound has the structure Eu3+:Li6Y(BO3)3 with a doping concentration of about 25%. We studied the absorption and emission spectra of the crystal and calculated the gain cross sections. The compound shows a strong emission peak at 613 nm and absorption at 394 nm, which is compatible with pumping by new blue laser diodes. These features make the Eu:LYB crystal a very interesting candidate for the development of DPSS lasers emitting in the visible range.

Spectroscopic properties of newly flux grown RE2O3:Yb3+ (RE=Y,Lu) laser crystals for high-power diode-pumped systems

Developing large laser grade cubic rare-earth sesquioxides (RE2O3, RE=Y,Sc,Lu) single crystals doped with Yb3+ ions stands as one of the most challenging endeavours of todays crystal growth1,2. Recent studies on cubic RE2O3 single crystals have demonstrated their laser potential and highlighted the extreme thermodynamic conditions in which their growth takes place1-3. In particular, the laser performances of Lu2O3:Yb3+ crystals make them likely to outperform betterknown rivals such as YAG:Yb3+ or KY(WO4)2:Yb3+ for 976 nm diode-pumped systems4. Several mm3-sized Yb3+-doped Y2O3, Gd2O3 and Lu2O3 single crystals were recently grown by a newly designed high-temperature solution growth method5, and characterized by means of X-ray diffraction, Fourier transformed infrared (FTIR) spectroscopy and electron probe microanalysis (EPMA). Spectroscopic characterizations (absorption and emission cross sections, visible anti-Stokes emission, fluorescence decays) of these new cubic RE2O3:Yb3+ (RE=Y,Lu) single crystals are presented.

Rare-earth doped halide crystals for laser applications: recent advances and future trends

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: Pr3+ doped fluorides, Yb3+ doped CaF2 and its isotypes, and Er3+ and Pr3+ doped chloride and bromide KPb2Cl5 and Tl3PbBr5.

Polarization-dependent angular distribution of the absorption behavior in Ytterbium-doped monoclinic LYB and LGB compounds

In this contribution we detail the full characterization of the anisotropy of the absorption properties of two different Yb-doped monoclinic borate compounds under polarized light. The studied crystals are Li6(Gd)0.75Yb0.25(BO3)3 and Li6Y0.75Yb0.25(BO3)3, respectively, grown by the Czochralski method. We focused on the study of their absorption at the zero line transition as a function of the polarization direction of the incident light for two different crystal cuts of each compound. We discuss the different Eigen frames that must be considered in these materials due to their monoclinic character, as well as the optimal crystal orientation for the considered absorption and the potential influences when used as laser materials.

Cation ordering in the double tungstate LiFe(WO4)2.

Single crystals of lithium iron tungstate, LiFe(WO(4))(2), were obtained using a high-temperature solution growth method. The analysis was conducted using the monoclinic space group C2/c, with β = 90.597 (2)°, giving R1 = 0.0177. The Li and Fe atoms lie on twofold axes. The structure can also be refined using the orthorhombic space group Cmcm, giving slightly higher residuals. The experimental value of β and the residuals mitigate in favour of the monoclinic description of the structure. Calculated bond-valence sums for the present results are closer to expected values than those obtained using the results of a previously reported analysis of this structure.

Lasing properties of new Yb-doped borate compounds with varying gadolinium and yttrium concentration

Ytterbium doped crystals have proven to be an attractive laser medium for continuous wave lasers as well as for short pulse generation [1–6] and have achieved established application in industrial laser systems. This is mainly due to the relatively small quantum defect, which limits the heating effect during the laser process, and the absorption spectrum of this ion that matches perfectly the emission wavelength of high power InGaAs laser diodes which can be used for pumping those laser crystals. Owing to the relatively large gain bandwidth depending on the host matrices Yb-doped crystals are suitable for ultrafast lasers down to the femtosecond regime.