Photon migration at multiple frequencies in YLiF4:Nd3+ crystal

A spatially resolved microluminescence technique was used to measure the spatial distribution of emitted light and photon propagation in Nd3+-doped YLiF4 crystal excited at 514 nm. The spatial distribution of the luminescence was studied and the energy transfer processes among neodymium ions were discussed. We measured the photon diffusion length for specific wavelengths. It was found that re-absorption by ground and excited states plays a crucial role to the propagation. With this information, the microluminescence technique has played a useful role in the investigation of energy transfer processes in rare-earth doped systems.