Optical switching a photon-avalanche-like mechanism in NdAl(BO) particles excited at 1064 nm by an auxiliary beam at 808 nm.

In recent years, an unconventional excitation of trivalent neodymium ions ( ) at 1064 nm, not resonant with ground-state transitions, has been investigated with the unprecedented demonstration of a photon-avalanche-like (PA-like) mechanism, in which the temperature increase plays a fundamental role. As a proof-of-concept, ( ) particles were used. A consequence of the PA-like mechanism is the absorption enhancement of excitation photons providing light emission at a broad range covering the visible and near-infrared spectra.