Visible-to-ultraviolet upconversion in Pr3+:Y2SiO5 crystals

The visible-to-ultraviolet upconversion in Pr3+:Y2SiO5 crystals have been investigated at room temperature for three different Pr3+ ion concentrations. The upconverted luminescence bands at the UV region from 270 to 350 nm were obtained with visible laser excitation. The upconversion mechanism was studied by observing the absorption and excitation spectra, the dependence of upconverted luminescence on pump power, and the decay profiles of the upconverted luminescence. It was found that the upconverted luminescence was produced by excited-state-absorption process using the 3PJ and 1I6 as intermediate states.