Ultrafast Manipulation of a Strongly Coupled Light–Matter System by a Giant ac Stark Effect

We demonstrate ultrafast control of a strongly coupled light–matter system via a giant ac Stark effect in a specially designed strongly coupled microcavity using ultrafast pump–probe spectroscopy. We observe polariton energy shifts larger than the Rabi energy, enabling the implementation of strong noninvasive potentials for robust and ultrafast polaritonic switches. A nonperturbative treatment has been utilized to correctly describe the underlying physics of the giant Stark shifts in our strongly coupled light–matter system and corresponds well to the experimental results. Our findings shed new light on nonperturbative interactions and pave the way for all-optical quantum technologies.