Growth, spectroscopy and laser operation of monoclinic Nd:CsGd(MoO4)2 crystal with a layered structure

Abstract

We report on the growth, structure, polarized spectroscopy and first laser operation of a double molybdate compound featuring a layered structure – the monoclinic Nd:CsGd(MoO4)2. Single-crystals of 3 at.% Nd:CsGd(MoO4)2 are grown from the flux using cesium trimolybdate (Cs2Mo3O10) as a solvent. They crystallize in the monoclinic system (sp. gr. P2/c) with lattice constants a = 9.5239(4) Å, b = 5.0752(5) Å, c = 8.0580(7) Å and β = 91.157(9)°. Nd:CsGd(MoO4)2 exhibits a perfect cleavage along the (100) plane. Polarized absorption and luminescence spectra of the Nd3+ dopant ion are measured. The maximum stimulated-emission cross-section is 29.0 × 10−20 cm2 at 1065.9 nm for light polarization E ||b. The luminescence lifetime is 145 μs. The transition probabilities are determined using the modified Judd-Ofelt theory yielding the intensity parameters Ω2 = 26.736, Ω4 = 12.736 and Ω6 = 17.771 [10−20 cm2] and α = 0.122 [10−4 cm]. Continuous-wave laser operation is achieved in cleaved single-crystal plates of Nd:CsGd(MoO4)2 yielding a maximum output power of 0.54 W at 1066 nm with a laser threshold of 70 mW, a slope efficiency η of 60.4% and a linearly polarized laser output (E ||b).