$125m · Series B · Semiconductors · Oxford, UK
Oxford-based Salience Labs has raised an $125m oversubscribed Series B led by Bullhound Capital. AMD Ventures, Intel Capital, SBI Group, Hudson River Trading and the British Business Bank joined the round, while Applied Ventures, Oxford Science Enterprises, Cambridge Innovation Capital and Silicon Catalyst Ventures returned. The British Business Bank separately confirmed that its participation was £10m. Salience says the capital will accelerate deployment of its optical circuit-switching technology, scale volume manufacturing and expand its Silicon Valley presence.
The network moves into the cost equation
Salience is building all-optical circuit switches for the connections between GPUs inside AI data centres. Rather than repeatedly converting traffic between optical and electrical signals at each switch, its architecture keeps data in the optical domain. The company says that removes transceivers used by conventional electrical switching and can cut latency, power consumption and cost per port; its published product benchmarks claim under 10 nanoseconds of latency and less than one watt per port.
That mechanism matters because expensive accelerators only produce useful work when data reaches them quickly enough. Salience's commercial task is therefore not simply to fabricate a faster component, but to qualify a switch that system builders can integrate across rack-scale networks. The company says its architecture is designed to connect thousands of GPUs across multiple racks. Strategic investment from AMD Ventures and Intel Capital is relevant ecosystem validation, but the funding announcement does not disclose a procurement contract or production deployment by either chipmaker.
Manufacturing becomes the next milestone
The round follows Salience's September demonstration of a 64-port silicon-photonic switch at ECOC 2026. The company describes 128- and 256-port products as future solutions, so those larger systems should not be treated as commercially deployed. Its February partnership with Tower Semiconductor moved the manufacturing programme from development into pre-production using Tower's silicon-photonics platforms, while work with Keysight addresses the testing environment needed around the device.
That sequence makes manufacturing yield, testing, reliability and customer qualification the next evidence points. The financing gives Salience room to build those capabilities and a second West Coast location, but the shift from demonstrations to repeatable volume output still has to be proven. Founded in 2021 from more than a decade of University of Oxford and University of Münster research, the company previously raised a $30m Series A in February 2025.
Explore this theme
Green Computing in the AI Era — Lorenzo Chiavarini, World Fund, Markus Bohl, Daria Saharova and Alois Eder, hosted on EUVC · 15 January 2025. The article maps optical computing and semiconductor advances as investment routes for reducing the energy burden of data-centre growth, directly extending the efficiency question behind Salience's switch architecture.
