Electronically Programmable Photonic Molecule

Physical systems with discrete energy levels are ubiquitous in nature and are fundamental building blocks of quantum technology. Realizing controllable artifcial atom- and molecule-like systems for light would allow for coherent and dynamic control of the frequency, amplitude and phase of photons. In this work, we demonstrate a photonic molecule with two distinct energy-levels and control it by external microwave excitation. We show signature two-level dynamics including microwave induced photonic Autler-Townes splitting, Stark shift, Rabi oscillation and Ramsey interference. Leveraging the coherent control of optical energy, we show on-demand photon storage and retrieval in optical microresonators by reconfguring the photonic molecule into a bright-dark mode pair. These results of dynamic control of light in a programmable and scalable electro-optic platform open doors to applications in microwave photonic signal processing, quantum photonics in the frequency domain, optical computing concepts and simulations of complex physical systems.