Spectra and energy levels of a layered Yb3+:CsGd(MoO4)2 crystal with perfect cleavage: a candidate for microchip lasers

Abstract

Thin mica-like Yb³⁺:CsGd(MoO₄)₂ crystals, with a perfect (100) cleavage plane, have been grown by a top seeded solution growth method from a flux of Cs₂Mo₃O₁₀. The cleavage habit has been found to be closely connected with the layered structure. The Stark-level positions of Yb³⁺ have been deduced from the excitation and emission spectra at 77 K with the aid of the Raman spectrum, indicating the largest ground-state splitting among the double molybdates and double tungstates ever reported except for Yb³⁺:LiLu(WO₄)₂. The emission cross-sections have been determined by the combinatorial reciprocity method and the Füchtbauer–Ladenburg formula. The wavelength dependence of the gain cross-section predicts a broad tuning range and potential sub-100 fs laser pulse generation. Taking into account the cleavage behavior, the crystal is particularly suitable for microchip lasers, in which thin platelets of gain media can be prepared by a simple cleavage technique.