Electronically Programmable Photonic Molecule: Control of Light through a Photonic Two-Level System
The paper presented in this paper introduces a significant stride toward harnessing photonic analogues of two-level systems. This work delineates a compelling method for effectively controlling photon dynamics in optical microresonators using an electronically programmable photonic two-level system. The authors focus on a system wherein photonic molecules emulate the discrete energy levels present in natural atomic systems, enabling coherent control over various optical parameters such as frequency, amplitude, and phase.
The primary demonstration involves photonic molecules composed of two coupled optical microring resonators on a lithium niobate platform. These rings form a coherent two-level system that exhibits rich physical phenomena typically observed in atomic systems, such as Autler-Townes splitting, Stark shifts, Rabi oscillations, and Ramsey interference, all controlled via external microwave excitation. The architecture provided in this work uniquely leverages lithium niobate's strong electro-optic properties, yielding a substantial modulation efficiency of 0.5 GHz/V and low optical loss, promoting extended photon lifetimes and large bandwidth capabilities.
The authors demonstrate the feasibility of controlling photon transitions between these photonic energy states with finely tuned microwave fields. In their experimental setup, the two-level photonic system coherently couples light, contributing insights into its coherent dynamics. Key results include the successful observation and control over Rabi oscillations, showing rotation between energy states at frequencies reaching 1.1 GHz. Additionally, Ramsey interference patterns manifest under carefully controlled pulse sequences, offering evidence of optical coherence over timescales dictated by the photonic molecule's cavity lifetime (∼1.6 ns).
A highlight of this research is the realization of photon storage and retrieval on-demand using a bright-dark mode configuration. By applying differential DC bias, the authors dynamically shift resonances between the coupled cavities, configuring one as optically bright and the other dark—a mode decoupled from external access. Microwave fields enable temporary transitions between these modes, allowing for photon trapping and precise retrieval cycles, effectively doubling the light storage period compared to the critically coupled bright modes.
The implications for advanced photonic application areas are manifold. Practically, this research underpins potential developments in microwave photonic signal processing and optical computing, providing means for dynamically reconfigurable optical circuits. Theoretically, these demonstrations present opportunities to further explore simulations of complex atomic behaviors in a photonic milieu, fostering deeper understanding and potentially inspiring new quantum photonic technologies.
Looking forward, continued exploration of fully integrated large-scale photonic-electronic systems can advance state-of-the-art efforts in quantum information processing at room temperature. The integration framework utilized herein suggests scalable fabrication routes toward uniting electronic and photonic circuits capable of advanced signal manipulation akin to those handled in quantum systems.
In conclusion, this paper presents an impactful exploration of dynamically controllable photonic systems, showcasing electronic programmability's potential to significantly advance the capabilities and functionalities in integrated photonics. Future studies capitalizing on these concepts could steer further technological breakthroughs in both classical and quantum realms, cementing the role of electronic-photonic hybrid platforms in next-generation technologies.