UNUSUAL CRYSTAL‐FIELD ENERGY LEVELS AND EFFICIENT LASER PROPERTIES OF YVO4:Nd

The spectral properties of Nd‐doped YVO4, grown from the melt, have been determined. In absorption the Stark split levels are reduced in comparison to other Nd‐doped materials. The Nd ion appears to be in a cubic crystal field even though it substitutes for Y whose point symmetry is less than (42m). The reduced Stark splitting, caused by an admixture of 4f and 5d wave functions, leads to efficient, low‐threshold laser action. Transfer of energy from the lattice to Nd ions is also observed.