Resonant optical superradiation at an interface

А. В. Андреев, O. Iu. Tikhomirov, Mikhail V. Fedotov

Lingjing Ji, Yizun He, Qingnan Cai +7 more

The interaction between light and cold atoms is a complex phenomenon potentially featuring many-body resonant dipole interactions. A major obstacle toward exploring these quantum resources of the system is macroscopic light propagation effects, which not only limit the available time for the microscopic correlations to locally build up, but also create a directional, superradiant emission background whose variations can overwhelm the microscopic effects. In this Letter, we demonstrate a method to perform "background-free" detection of the microscopic optical dynamics in a laser-cooled atomic ensemble. This is made possible by transiently suppressing the macroscopic optical propagation over a substantial time, before a recall of superradiance that imprints the effect of the accumulated microscopic dynamics onto an efficiently detectable outgoing field. We apply this technique to unveil and precisely characterize a density-dependent, microscopic dipolar dephasing effect that generally limits the lifetime of optical spin-wave order in ensemble-based atom-light interfaces.

Jin-Fang Pan, Sunil Sandhu, Yijie Huo +5 more

We show that an all-optical analogue to the Dicke superradiance effect can be observed in on-chip photonic crystal resonator systems where two resonators are separated by a distance much longer than the wavelength of the optical resonators' resonance. In addition, we provide the experimental observation of structural tuning of the superradiance effect in micron-sized optical resonators in a silicon photonic crystal slab.

A. V. Andreev

Xinchao Zhou, Deepak A. Suresh, F. Robicheaux +1 more

We experimentally and theoretically study collective emission of a dense atomic ensemble coupled to a single mode in a nanophotonic microring resonator. Because many cold atoms are localized in a small volume, these trapped atoms collectively couple not only to the guided resonator mode but also to the nonguided modes in free space. Through tuning the atom-photon coupling and by adjusting the number of trapped atoms, we demonstrate superradiant emission to the microring resonator. For photon emission via the nonguided modes, our study reveals signatures of subradiance and superradiance when the system is driven to the steady state and to the timed-Dicke state, respectively. Our experimental platform thus presents the first atom-light interface with selective collective emission behavior into a guided mode and the environment. Our observation and methodology could shed light on future explorations of collective emission with densely packed quantum emitters coupled to nanophotonic light-matter interfaces.

P. V. Zinov’ev, Nataliya B. Silaeva, Yu. E. Sheǐbut