VOMBAT—On-chip source for entangled photons

© putilov_denis/stock.adobe.com, Fraunhofer IAF
Miniaturized sources of entangled photons are the building blocks of quantum-safe transmission

Light quanta, so-called photons, are the information carriers of quantum communication and enable, for example, the secure transmission of information based on quantum physical principles. Sources of entangled photon pairs in the frequency range of the low-loss telecommunications bands are essential for the integration of quantum communication into the existing fiber optic infrastructure and the associated long-distance transmission. The aim of the project VOMBAT is to develop a source for entangled photon pairs, in which the required pump source and the generation of the entangled photon pairs are integrated in one chip. This photon pair source will be developed and manufactured on the basis of the material system AlGaAs (aluminum gallium arsenide).


VOMBAT—Miniaturized telecom-scale entanglement source based on AlGaAs Bragg reflection waveguides



2023 – 2026


German Ministry of Education and Research BMBF


Dr. Marko Härtelt, Fraunhofer IAF


  • Investigation of different concepts for monolithic integration of a pump structure in Bragg reflection waveguides (BRWs) and development of active Fabry-Perot and lattice-stabilized BRWs (Fraunhofer IAF and Ferdinand-Braun-Institut)
  • Investigation of hybrid coupling of BRW lasers with a PIC for wavelength multiplexing with at least 8 channels (Fraunhofer HHI)
  • Test and implementation of miniaturized entanglement sources in the telecom domain on a fiber test track (Saarland University)

Optoelectronics at Fraunhofer IAF

We develop semiconductor lasers and photodetectors for a wide range of applications such as quality control and monitoring of industrial processes.


Quantum systems at Fraunhofer IAF

We conduct research on diamond-based devices and innovative solutions for future topics in the field of quantum computing and quantum sensing.