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arXiv · 2504.12376

Ultrafast switching of telecom photon-number states

Kate L. Fenwick·Frédéric Bouchard·Alicia Sit·Timothy Lee·Andrew H. Proppe·Guillaume Thekkadath·Duncan England·Philip J. Bustard·Jeff S. Lundeen·Benjamin J. Sussman
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Abstract

A crucial component of photonic quantum information processing platforms is the ability to modulate, route, convert, and switch quantum states of light noiselessly with low insertion loss. For instance, a high-speed, low-loss optical switch is crucial for scaling quantum photonic systems that rely on measurement-based feed-forward approaches. Such a device will also ideally be capable of operating on photon-number states, which can act as non-Gaussian resources. Here, we demonstrate ultrafast all-optical switching of heralded photon-number states, of up to 6 photons, using the optical Kerr effect in a single-mode fiber. A local birefringence is created by a high-intensity pump pulse at a center wavelength of 1030 nm which overlaps temporally with the 1550 nm photons in the fiber. A switching efficiency of $>$99 % is reached with a resolution of 2.3 ps, an insertion loss of $2.27\pm0.08$ dB, and a signal-to-noise ratio of 32,000.

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Kate L. Fenwick, Frédéric Bouchard, Alicia Sit, Timothy Lee, Andrew H. Proppe, Guillaume Thekkadath, Duncan England, Philip J. Bustard, Jeff S. Lundeen, Benjamin J. Sussman. 2025-04-16. Ultrafast switching of telecom photon-number states. https://arxiv.org/abs/2504.12376

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