A crystal fiber of yttrium scandate YScO 3 doped with Nd 3+ , with a cubic bixbyite-type crystal structure, has been synthesized through laser-heated pedestal growth for the first time. Its crystal structure has been determined using low-temperature (150 K) single-crystal X-ray diffraction: space group Ia3̅ , a = 10.2166(1) Å, R = 0.0177. A new phase was characterized with micro-Raman scattering and fluorescence. Fluorescence excitation measurements show two complex local positions of Nd 3+ in the crystal structure with lifetimes τ 1 = 290 and τ 2 = 250 μs ( 4 F 3/2 multifold) at a temperature T = 77 K.

The results of the study of the output laser beam spatial characteristics of the Nd:Gd3Ga5O12 (Nd:GGG) disk laser with multipoint spatially periodic diode-pumping are presented. The presence of the optical coupling between the TEM00 lasing channels is demonstrated. The phase-locking of channels was realized due to partial overlapping of laser beams inside the pumped areas of the active element disk.

A study of how the transverse distribution of an optical path changes in a Nd:YVO4 active disk was carried out in a ten-beam spatially periodic diode pumping in the one-dimensional case. The pumping beams’ transverse dimensions were comparable with the distances between them. The investigations were carried out using laser interferometry methods. It was found that the optical thickness changing in the active disk along the line of pumping spots was well described by a Gaussian function.

The thulium-doped yttrium scandate crystal fiber has been obtained by the laser-heated pedestal growth method. The crystal belongs to the bixbyite type, has a cubic structure and crystallizes in the Ia3 space group. The lattice parameters (a=10.224(1) Angstrem) have been determined using the powder X-ray diffraction. Spectral-kinetic measurements have allowed to detect two symmetrically independent optical centers of Tm3+ ions in the crystal fiber. Keywords: bixbyite, optical center, rare-earth ion, laser-heated pedestal growth.