Superconducting quantum computers work with microwave signals at temperatures near absolute zero, which makes it hard to connect them to each other. QphoX, a start-up in Delft, builds a quantum transducer, which it has called a quantum modem, that converts qubit signals from microwaves to optical photons that can travel through ordinary fibre at room temperature, so that quantum processors can be networked.
The European Innovation Council granted €2,500,000 towards a €3.74 million project, QModem, which ran from July 2022 to June 2024. The EIC Fund joined QphoX's €8 million round in January 2024, and in 2026 the EIC selected QphoX for €10 million of equity from its STEP Scale-Up scheme. In March 2026 QphoX launched the Quantum Transducer, with IBM as the first user.
Company file
- Legal entity
- QphoX B.V., Delft, Netherlands
- Products
- Quantum Transducer; cryo switch controllers; optical readout
- Partners
- IBM, Rigetti, IQM, QuantWare, Welinq, Bluefors, Qblox
- Investors
- QDNL Participations, EIC Fund, Quantonation, Speedinvest, High-Tech Gründerfonds, Delft Enterprises
- Contracts
- US AFRL contract with Rigetti, $5.8M
- EIC project
- QModem, 1 Jul 2022 to 30 Jun 2024, closed
- EIC funding
- Blended finance; later EIC STEP Scale-Up
Where QphoX Stands Today
According to QphoX, the Quantum Transducer "enables quantum information to travel through optical fiber networks at room temperature over large distances", and IBM will integrate it with its Quantum Networking Unit test devices. The company also reports 100 cryo switch controllers in operation around the world, a partnership with the cryostat maker Bluefors on optical control of qubits, and a role in European quantum pilot lines. Its news page lists a $5.8 million US Air Force Research Laboratory contract with Rigetti. Revenue is not disclosed.
The Technology: Turning Microwaves Into Light
According to the CORDIS report, QModem reached a transduction efficiency "as high as 0.9%", with added noise "limited to a few photons", a bandwidth of 14.8 MHz and repetition rates up to 100 kHz. With Rigetti Computing it demonstrated "optical readout of a superconducting qubit", work QphoX later published with Rigetti and Qblox in Nature Physics.
"Enables quantum information to travel through optical fiber networks at room temperature over large distances."
QphoX, on the Quantum Transducer, March 2026What the EIC Project Promised, and What CORDIS Shows
QModem promised to develop "the world's first quantum modem". CORDIS reports working prototype transducers and the qubit readout with Rigetti, and describes a platform designed for scaling. The commercial product followed in 2026.
- A working transducerDeliveredPrototype with measured efficiency.
- Qubit demonstrationDeliveredOptical readout with Rigetti.
- A productDeliveredQuantum Transducer, 2026.
- Networked quantum computersNot yetIBM test integration.
What Has Happened Since the Award
The Money
QphoX announced €6.5 million in funding through the EIC Accelerator programme; CORDIS records the grant at €2.5 million. In January 2024 it raised €8 million led by QDNL Participations, with the EIC Fund, Quantonation, Speedinvest, High-Tech Gründerfonds and Delft Enterprises. The 2026 STEP Scale-Up decision adds up to €10 million of EIC equity.
What cannot be checked
QphoX's revenue, the price of its products, the current efficiency of the commercial transducer and the full size of the round the STEP investment belongs to are not public.
Why Europe Should Care
Linking quantum processors together is one route to larger quantum computers, and QphoX supplies a component for it. The EU has now backed it three times: the EIC grant, the EIC Fund seed investment and STEP Scale-Up equity. Its first launch customer is a US company.
What the project promised
The world's first quantum modem.
What the record shows
A working transducer, a Nature Physics paper, a launched product with IBM and more EU equity.
The Verdict
From prototype to product, with the EU doubling down
QModem delivered what it promised, and QphoX has turned it into a product and a growing set of partnerships. The EU has since increased its stake. Its revenue remains undisclosed.
QphoX has not been asked for comment for this article. It is based entirely on company statements and EU project data, linked throughout.
