2025/08/08 by Booton, Georgia, Wasawo, Tabijah, Davis, William O. C. +5
#FOS: Physical sciences #Optics (physics.optics) #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.2508.06255
Optical switching remains a key outstanding challenge for scalable fault-tolerant photonic quantum computing due to the trade-off between speed, bandwidth, and loss. Scalable quantum photonics demands all three, to enable high computational clock rates and resource efficient scaling to large systems. We present a cavity-based optical switch that overcomes this limitation, demonstrating 22 ns rise time, insertion loss of 2.4 dB, and 17.5 dB extinction ratio. All-optical control is achieved via phase modulation of a signal field detuned from the near-degenerate two-photon absorption ladder in warm rubidium vapor. The ultimate performance of our switch, combining both speed and efficiency, will find applications in active multiplexing, loop-based quantum memory, and feedforward for quantum error-correction protocols.