REFLOW

Microwave Photonics takes part in the Interreg-COMET project under the subproject REFLOW. The Interreg-COMET project — short for “Comaking the Einstein Telescope” — is a cross-border cooperation initiative under the Interreg VI Programme Deutschland-Nederland, running from October 2025 to December 2028 with a total project budget of €4,678,080.09. The project unites the Netherlands and Germany in their joint efforts to advance the development of the Einstein Telescope (ET), a planned underground observatory that will be one of Europe’s most advanced research facilities for gravitational wave detection, aimed at answering fundamental questions about the universe.

The core objective of COMET is to develop innovative technological solutions for the key challenges that need to be overcome to realise the Einstein Telescope. These include vibration-free cooling systems, advanced optics, and high-performance data processing, as well as the development of a vacuum network spanning more than one hundred kilometres. To achieve this, the project brings together the complementary expertise of small and medium-sized enterprises (SMEs) and knowledge institutions from across the Dutch-German border region in collaborative, cross-border consortia. Beyond matchmaking and partnership building, COMET also provides financial support to participating organisations and opens up access to international markets.

The subproject, Ultra-Low-Noise RF-over-Fiber System for LO Reference Distribution in the Einstein Telescope, or REFLOW
in short, brings together complementary expertise from Sabratha Photonics B.V. (NL) and Microwave Photonics
GmbH. Sabratha specializes in thin-film lithium niobate (TFLN) photonic integrated circuits, with in-house
capabilities for low-loss chip fabrication and the development of high-efficiency, high-extinction-ratio electro-optic modulators. Microwave Photonics contributes expertise in RF-over-fiber (RFoF) technologies, including low-noise photodiodes and laser systems. Together, the partners cover the full value chain from photonic chip design and fabrication to system-level RFoF implementation.

The project is led by Oost NL as Lead Partner and carried out together with NMWP, LIOF, Emsland GmbH, TCNN, and the Transfer Agency of FH Münster. The project is co-funded by the European Union, the Dutch Ministry of Economic Affairs (EZ), MWIKE NRW, the State Chancellery of Lower Saxony, and several Dutch provinces.