Non-stationary testing of avalanche-like behavior of up-conversion luminescence

Abstract

Nonlinear coupling of pumping rates in pump channels can produce effects very similar to the photon avalanche in up-conversion luminescence in the absence of a true avalanche. Stationary luminescence intensity can depend on the pump intensity practically in the same way. Here we show that time-dynamics for true avalanche and for avalanche-like processes are drastically different. Based on measuring the development times of stationary luminescence for several pump intensities, a simple test is proposed to reveal the nonlinear process underlying the observed avalanche-like effect.