Conversion of infrared radiation into visible emission in YVO4 crystals doped with ytterbium and holmium

The conversion of the infrared (IR) radiation at 975 nm into the visible emission in the Czochralski grown YVO4 crystals containing several different concentrations of Yb(super 3+) and Ho(super 3+) is investigated. An explanation of the mechanisms involved in the excitation process and at the assessment of laser potential associated with upconverted red emission is given.