QuiX Quantum launches PACU for scalable photonic chips

QuiX Quantum has introduced PACU, a Photonic Assembly Control Unit for its photonic quantum systems, as part of its roadmap towards universal quantum computers.

The new control unit is designed as a standardised layer for operating photonic chips in a rack-mountable format. It can host photonic chips with up to 1,000 low-speed phase shifters and up to 32 high-speed phase shifters, providing the control infrastructure needed for more complex photonic architectures.

Universal quantum computers are intended to run a broad range of quantum algorithms rather than a narrow set of tasks. That goal has become an important marker for hardware developers seeking general-purpose systems for scientific, industrial and commercial use.

Based in Enschede in the Netherlands, QuiX Quantum is developing quantum computing hardware built on integrated silicon nitride photonic chips. Its systems are designed for modularity and compatibility with data centre and high-performance computing environments.

Control layer

PACU is intended to address a technical hurdle in photonic quantum computing: controlling a growing number of tunable elements on larger chips while maintaining precision and reducing operational complexity. As photonic systems scale, control hardware must also support calibration, monitoring and integration into computing environments outside research laboratories.

The unit comes in a 3U, 19-inch rack-mount design and includes Ethernet and USB connectivity, air cooling, E2000 optical connectors, individual tunable-element control, overheat protection, and condition feedback from the photonic assembly to the control unit. PACU can update all phase shifters with a response time of below 2 milliseconds.

It also includes 32 high-speed connectors for interfacing with external high-speed control systems, a feature relevant to future measurement-based photonic quantum computing architectures.

The design is also intended to change how photonic assemblies are connected and maintained. Rather than relying on flat cables, assemblies can be linked through board-to-board connectors, creating a more resilient interface and supporting hot-swappable operation.

Scaling systems

QuiX Quantum positioned the unit as part of the broader engineering work needed to move photonic quantum systems into more practical deployment settings. In data centres and HPC environments, footprint, serviceability and system stability are likely to matter as much as raw quantum performance.

PACU is intended to improve reproducibility, as well as maintenance and replacement workflows. By combining rack-based integration, air cooling, monitoring and protection in one unit, the company says it has created a repeatable control architecture for current photonic chips and future systems.

The business was founded in 2019 and has offices in the Netherlands and Germany. It describes itself as a European photonic quantum computing company pursuing a fabless approach as it develops universal photonic quantum computing systems.

A key part of that strategy is the use of photonics as the basis for a modular system design that can be integrated into hybrid quantum-classical computing environments. QuiX Quantum argues that standardising the control layer is necessary if photonic hardware is to move beyond bespoke laboratory setups.

Stefan Hengesbach, chief executive officer of QuiX Quantum, said the launch reflects the need for more scalable support systems around the chips themselves.

"As photonic quantum chips become more capable, the systems around them must scale as well. PACU gives us a common control architecture across our photonic platform. It is designed to make our systems more modular, maintainable and ready for integration into larger quantum computing environments," he said.