Cavity-based optical switching via phase modulation in warm rubidium vapor

TL;DR

This paper introduces a cavity-based optical switch using phase modulation in warm rubidium vapor, achieving fast switching with low loss and high extinction, suitable for scalable quantum photonics.

Contribution

The authors demonstrate a novel all-optical switch with improved speed and efficiency, overcoming previous limitations in quantum photonic switching technology.

Findings

22 ns rise time achieved

Insertion loss of 2.4 dB

17.5 dB extinction ratio

Abstract

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.