Laser-Based Tuning of Light–Matter Interactions

Ebrahim E. Elsayed

Thomas H. Doherty, Axel Kuhn, Ezra Kassa

We report the realisation of a high-finesse open-access cavity array, tailored towards the creation of multiple coherent light-matter interfaces within a compact environment. We describe the key technical developments put in place to fabricate such a system, comprising the creation of tapered pyramidal substrates and an in-house laser machining setup. Cavities made from these mirrors are characterised, by laser spectroscopy, to possess similar optical properties to state-of-the-art fibre-tip cavities, but offer a compelling route towards improved performance, even when used to support only a single mode. The implementation of a 2×2 cavity array and the independent frequency tuning between three neighbouring sites are demonstrated.

V. M. Akulin, Sergey S. Alimpiev, Nikolai V. Karlov +1 more

Lange, Christian M

Quantum light-matter interactions form the basis of many quantum technologies and much fundamental research. Organic molecules are an impressive platform for the generation of quantum light, both as single photon emitters and as collective systems. In this work, I investigate quantum light-matter interactions with molecules of dibenzoterrylene in crystals of anthracene. I outline methods to grow dibenzoterrylene-doped anthracene crystals, and I characterize the optical properties of cryogenically cooled molecules. I prepare collective systems composed of pairs of molecules interacting through their free-space electromagnetic fields. I demonstrate a method to tune interacting molecules into resonance to form superradiant and subradiant collective states. Finally, I present a platform for solid-state cavity QED based on molecules of dibenzoterrylene coupled to a nanophotonic cavity. This demonstration establishes a route toward scalable deterministic photon generation with molecules. I also tune pairs of cavity-coupled molecules into resonance to form distributed collective states, opening the door to cavity-mediated many-body interactions.

Willie J. Padilla

Motoaki Bamba, Tetsuo Ogawa

We investigate theoretically the light amplification by stimulated emission of radiation (laser) in the ultrastrong light-matter interaction regime under the two-level and single-mode approximations. The conventional picture of the laser is broken under the ultrastrong interaction. Instead, we must explicitly discuss the dynamics of the electric field and of the magnetic one distinctively, which make the ``laser'' qualitatively different from the conventional laser. We found that the laser generally accompanies odd-order harmonics of the electromagnetic fields both inside and outside the cavity and a synchronization with an oscillation of atomic population. A bistability is also demonstrated. However, since our model is quite simplified, we got quantitatively different results from the Hamiltonians in the velocity and length forms of the light-matter interaction, while the appearance of the multiple harmonics and the bistability is qualitatively reliable.