Vexlum to develop a yellow guide star laser for the European Space Agency to accelerate high-bandwidth satellite communication deployment

The rising demand for laser-based, high-bandwidth data transfer between telescopes and satellites faces challenges from the growing number of satellites in orbit, atmospheric disturbances, and the bulky, costly communication technology currently limited to only the largest telescope installations. The work aims to make yellow laser technology more accessible for smaller telescopes, bringing high-bandwidth data transfer to more telescopes around the world.

TAMPERE, Finland (November 6th, 2025) Vexlum, a manufacturer of advanced semiconductor lasers for high-impact applications, has entered into a contract with the European Space Agency (ESA) aimed at enabling broad access to more telescopes around the world to use high-bandwidth optical communication between the Earth and orbiting satellites through the eventual development of a VECSEL-based adaptive optics system. These yellow lasers will make it possible for a larger number of telescopes to communicate large datasets, such as hyperspectral images, in near real-time.

Currently, the benefits of adaptive optical correction systems are limited to large telescopes with the space and budget to operate systems that overcome imaging fuzziness created by atmospheric air currents. Vexlum’s technology addresses the key challenges of space-to-ground optical links, including turbulent air currents and the slower transfer speeds of radio waves, by eliminating the need for the massive, costly yellow lasers used in ELTs.

By making adaptive optics accessible to smaller telescopes, Vexlum’s approach opens the door to faster delivery of critical information, such as hyperspectral imaging for monitoring wildfires, floods, and ecosystems, as well as more precise tracking of satellites and space debris to enable trajectory corrections and collision avoidance.

“With the growing number of satellite constellations and the demand for greater data volume, we are at a pivotal moment for space communications,” said Andrea Di Mira, Optical System Engineer at ESA/ESOC European Space Operations Centre. “This contract with Vexlum directly supports our goals goals in Europe of advancing optical ground station technology by significantly reducing costs and complexity   – key aspects for high-speed optical links. By enabling more ground stations, including compact and automated solutions, to support high-throughput data transfers,, we are not only addressing current communication bottlenecks but also building a more robust, scalable and accessible infrastructure for the future of Earth observation, space exploration and global connectivity.”

First, the work will focus on developing and prototyping a new laser system that can generate an artificial guide star in the atmosphere. This virtual reference point allows telescopes to precisely measure and correct for atmospheric distortions, ensuring that high-speed laser links remain stable and efficient, regardless of atmospheric conditions or time of day.

The compact size of Vexlum’s lasers makes the technology more accessible for use by smaller telescopes and observatories around the world with smaller budgets. Reducing the cost of yellow lasers by 50%, one-meter class telescopes can participate in the high-tech communication network previously limited to much larger, more expensive observatories.

 “We are excited to have been awarded this major development contract that builds on our unique laser-system platform exploiting the Vertical-External-Cavity Surface-Emitting Lasers (VECSEL) concept. Our laser systems have already seen a rapid market adoption in quantum technology applications for example atomic clocks, semiconductors, and quantum computing,” said Jussi-Pekka Penttinen, CEO and Co-founder of Vexlum. “VECSELs present an ideal technology for creating laser spectral colors for special applications that benefit from a smaller, cost-effective format than existing solutions. Delivering a high-power yellow laser tuned to the sodium line allows telescopes to correct atmospheric aberrations, leading to clearer observation of celestial objects.”

VECSELs have a wide variety of future applications, including medical diagnostics, precision manufacturing, and high-resolution scientific imaging.

Vexlum

Vexlum is a Finnish deep-tech company specializing in high-power semiconductor laser systems based on its innovative Vertical-External-Cavity Surface-Emitting Laser (VECSEL) technology. Spun out from Tampere University in Finland, Vexlum develops and manufactures cutting-edge lasers that offer unmatched performance in terms of system size, laser power, and cost for demanding applications in quantum technology, medicine, scientific research, and the semiconductor industry. For more information, visit www.vexlum.com.

European Space Agency

The European Space Agency (ESA) is Europe’s gateway to space. Its mission is to shape the development of Europe’s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world. ESA is an international organization with 22 Member States. By coordinating the financial and intellectual resources of its members, it can undertake programmes and activities far beyond the scope of any single European country. For more information, visit www.esa.int.