A nanocrystal shines on and off indefinitely

Optical probes have led to numerous breakthroughs in applications like optical memory, nanopatterning, and bioimaging, but existing options have limited lifespans and will eventually 'photobleach.' New work demonstrates a promising, longer-lasting alternative: ultra-photostable avalanching nanoparticles that can turn on and off indefinitely in response to near-infrared light from simple lasers.