HIFI – Highly integrated quantum frequency converter with highest fidelity based on innovative laser, fibre and production technology

Non-linear optical source for entangled photons as a technology basis for quantum frequency converter
© Fraunhofer ILT, Volker Lannert
Non-linear optical source for entangled photons as a technology basis for quantum frequency converter

The photon is of outmost importance in all areas of quantum technologies as it is the mobile carrier of quantum information. Quantum frequency conversion, i.e. the possibility of specifically changing the frequency or wavelength of the photon, is therefore a key capability in the technical implementation of quantum effects.

The HiFi consortium has dedicated itself to the systematic advancement of quantum frequency converters (QFC) and the required basic technologies. To transmit light quanta in fibre-optic-based networks with low losses, QFC are needed for conversion into the telecom band. In the future, such networks will interconnect quantum processors and registers of different computers over long distances in order to share information and resources confidentially and securely and to increase the computing power of quantum computers.

As part of the HIFI project, Fraunhofer IAF is developing single-frequency semiconductor disk lasers specifically designed as a powerful, low-noise pump source for quantum frequency converters. These will emit in the wavelength range of 2.0 - 2.2 µm and their emission frequency will be actively locked to meet the rigorous requirements of QFCs regarding absolute wavelength accuracy.


HIFI – Hochintegrierter Quantenfrequenzkonverter höchster Fidelität auf Basis innovativer Laser-, Faser- und Produktionstechnologie



2021 – 2024


Funded by the German ministry of education and research BMBF

FKZ 13N1525


Menlo Systems GmbH

Further information

Project website


More information (in German) on the project can be found on the project website:

Optoelectronic Devices

We mainly develop photodetectors and semiconductor lasers for the infrared spectral range.

Quantum Systems

Diamond-based devices and innovative solutions for quantum computing and quantum sensor technology.