Design, growth, and characterization of Y 2 Mo 4 O 15 crystals for Raman laser applications.

A new crystal Y 2 Mo 4 O 15 with dimensions of 14 × 12 × 5 mm 3 was successfully grown via a top-seeded solution growth (TSSG) method. The crystal structure shows that Y 2 Mo 4 O 15 crystallizes in the monoclinic space group P 2 1 / c (No. 14, a = 6.8110(4) Å, b = 9.5833(6) Å, c = 10.5124(7) Å, β = 105.512(7)°, and Z = 2) with Mo 4 O 15 and YO 7 polyhedra as basic structural units. Optical transmittance spectra of the Y 2 Mo 4 O 15 crystal exhibited a broad transmission range from 345 nm to 5575 nm. The group theory calculation and spontaneous Raman spectra show that the Y 2 Mo 4 O 15 crystal has 63 IR-active modes (32A u + 31B u ) and 60 Raman-active modes (30A g + 30B g ). The strongest Raman shift is located at 953 cm -1 caused by the asymmetric stretching vibrations of the Mo-O bonds. The spontaneous Raman spectra and the possibility of rare-earth doping to the Y 2 Mo 4 O 15 crystal indicate the Y 2 Mo 4 O 15 crystal to be a promising Raman and self-Raman crystal.