Extended Data Fig. 3: The effect of temperature on photon avalanche.
a, Schematic drawing of temperature control setup. b, Power dependence curves of NaYF4:Yb/Pr(15/0.5%)@ NaYF4 under different temperature conditions. It can be seen from the results that the nonlinear slope decreases slowly with rising temperature because the increasing temperature leads to the acceleration of phonon relaxation and affects the population of the metastable state, hindering the construction of PA. This also indicates that the heating effect of MPA nanoparticles caused by the laser itself is not obvious for the experiments under room temperature, otherwise the elevated temperature will weaken the PA nonlinearity.
