Frequency upconversion of orange light into blue light in Pr3+-doped fluoroindate glasses

Excitation of the transition 3H4¡æ1D2 in a Pr3+-doped fluoroindate glass at ¡­588 nm results in efficient blue emission at 480 nm which is ascribed to the 3P0¡æ3H4. The upconversion process is due to an energy transfer involving a pair of Pr3+ ions. The dynamical behavior of the anti-Stokes emission is described using a rate-equation model which allows one to obtain the energy-transfer rates involving the pair states which contribute to the upconversion process