Energy up-conversion in LaF3:Nd3+

Abstract
On resonant excitation of the D levels of LaF3:Nd3+ with yellow laser line, ultraviolet fluorescence is detected from L levels. It is found that both sequential two photon excitation (STEP) process and energy transfer up‐conversion (ETU) process are responsible for the population drain mechanism from the lower D levels to the higher L levels. A rate equation model has been developed which also supported the ETU process.