Edouard Hertz

Light beams carrying orbital angular momentum (OAM) have become over the past few years a subject of widespread interest with unprecedented applications in various fields such as optical communication, super‐resolution imaging, optical tweezers, or quantum processing. In the present work it is demonstrated that gas‐phase molecules can be used as a quantum interface to store an OAM carried by an ultrashort laser pulse. The interplay between spin angular momentum and OAM is exploited to encode the spatial phase information of light beams into rotational coherences of molecules. The embedded spatial structure is restored on‐demand with a reading beam by taking advantage of field‐free molecular alignment. The strategy is successfully demonstrated in CO 2 molecules at room temperature. Apart from applications to broadband coherent buffer memory, this method opens new functionalities in terms of optical processing and versatile control of OAM fields as well as for a deeper understanding of their role on various molecular processes.