A Cavity-Integrated High-Speed Low-Loss Optical Switch in Rubidium Vapour

The ability to dynamically route and manage optical signals at high speeds with low-loss is a substantial challenge in quantum optics. Existing optical switches, such as electro-optic phase modulators either achieve high-speed or low insertion losses, but rarely both. However, optically-controlled phase modulation in atomic vapour promises a pathway for efficient, high-bandwidth switching [1]. These characteristics are critical for single photon multiplexing in quantum technologies, implementing loop memory schemes and addressing scalability challenges in photonic quantum computation [2]. We present a cavity based system that can deliver high-speed all-optical switching of a signal field with minimal loss by accessing the strong two photon absorption in warm rubidium vapour via a counter-propagating control field.