Lasing Yb3+ in crystals with a wavelength dependence anisotropy displayed from La2CaB10O19

We report spectroscopic and laser properties for propagation directions outside the principal axes of Yb³⁺-doped low symmetry laser crystals with a special devotion to the wavelength dependence anisotropy. We illustrate our report with experimental data in the 900–1075 nm range of wavelengths from the Yb³⁺:La₂CaB₁₀O₁₉ monoclinic crystal excited under laser diode pumping at 975 nm. This study, which makes easier the realization of Yb³⁺ lasers with an efficient free-running operation at the wavelength having the highest emission intensity or at a specified wavelength, or emitting two frequencies with a specified frequency difference, is of promising interest for applications.