Nonlinear interactions between light and matter are at the heart of some of the most powerful tools in modern optics, but pushing these processes to their limits has long been hampered by a fundamental constraint: the stronger you make the laser, the more likely it is to destroy whatever it illuminates.

Through new experiments detailed in Nature, Jian Wu and colleagues at East China Normal University in Shanghai have found a way around this problem, by exploiting the quantum nature of light itself.