Investigation of a random lasing in K5PrLi2F10 powders

Abstract Emission peculiarities of K 5 PrLi 2 F 10 polycrystalline powders consisting of grains with mean diameter ranging from 25 μm to 200 μm were investigated as a function of the excitation energy density and temperature. Powder samples were excited at 470 nm by light pulses 4 ns long delivered by an Optical Parametric Oscillator. It has been found that at temperatures below about 100 K almost all intensity of emission emerging from samples is contained in a single narrow and very intense red line related to the transition from unsplit 3 P 0 level to a crystal field component of the 3 H 6 level when the incident energy density is above well defined threshold value. Recorded plots of emission intensity versus incident excitation energy density made it possible to determine the threshold values and their dependence on the sample temperature. It has been concluded that the temperature-dependent self-quenching of the 3 P 0 emission restricts occurrence of the phenomenon observed to the low temperature region.