Control of the spectral parameters of neodymium ions in anisotropic crystals with a scheelite structure

The spectral parameters of neodymium ions in anisotropic YLiF₄, SrMoO₄, PbMoO₄, CaMoO₄, SrWO₄, and BaWO₄ crystals with a scheelite structure are experimentally studied in the region of 1 mm. The luminescence spectra of neodymium ions at the ⁴F_3/2 → ⁴I_11/2 transition in these crystals exhibit pronounced polarisation dependences. It is shown that, using different orientations of the active laser element and separating a particular radiation polarisation, one can control the spectral dependence of the active medium gain, switch the laser wavelength, and create dual-wavelength lasers. A dual-wavelength Nd³⁺ : YLiF₄ laser emitting at λ = 1047 and 1053 nm with identical linear polarisations and good temporal and spatial matching is demonstrated.