SES Trials Cailabs Optical Ground Stations for High-Speed Laser Satellite Links

European satellite operator SES is partnering with French photonics firm Cailabs to test a new generation of optical ground stations designed to support high-speed laser communications between satellites and Earth. The trials will evaluate the performance of Free Space Optics (FSO) in real-world atmospheric conditions and aim to validate critical technologies for future secure, high-throughput space-to-ground data links.

Strategic Shift Toward Optical Communications

As traditional radio frequency (RF) bands become increasingly congested, satellite operators are turning to optical communication—particularly laser-based Free Space Optics (FSO)—to meet growing bandwidth demands. Optical links offer several advantages over RF systems:

Higher data throughput (up to multiple Gbps or even Tbps)
Lower probability of interception or detection (LPI/LPD)
No need for spectrum licensing
Resistance to RF jamming and interference

However, FSO faces challenges such as atmospheric turbulence, cloud cover, and beam pointing accuracy. Ground station technology must therefore compensate for these factors using advanced adaptive optics and beam shaping techniques.

Cailabs’ CANUNDA Technology at the Core

The SES-Cailabs collaboration centers on testing Cailabs’ proprietary CANUNDA adaptive optics platform within its optical ground stations. CANUNDA leverages multi-plane light conversion (MPLC) technology—a method that reshapes distorted wavefronts caused by atmospheric turbulence into clean Gaussian beams suitable for coherent detection.

This capability is critical when establishing stable downlinks from satellites in Low Earth Orbit (LEO) or Geostationary Orbit (GEO), where beam divergence and scintillation can severely degrade signal quality. According to Cailabs, its technology enables robust communication even under degraded weather conditions.

SES’s Optical Strategy and Use Cases

For SES—a Luxembourg-based operator with a fleet spanning GEO and MEO orbits—the adoption of optical links aligns with its roadmap toward high-throughput secure connectivity. The company is exploring multiple use cases:

Data relay from LEO satellites: Enabling real-time Earth observation data transfer without reliance on RF bottlenecks.
Secure government/military comms: Supporting resilient command-and-control channels immune to RF jamming or eavesdropping.
Backhaul augmentation: Providing ultra-high-speed trunk links between space assets and terrestrial fiber networks.

The current tests will help SES evaluate how well the Cailabs terminals integrate into existing ground infrastructure while meeting link budget requirements under variable environmental conditions.

Technical Challenges in Ground-Based Laser Comms

The performance of laser communication systems is highly sensitive to atmospheric effects—especially in urban or coastal environments where humidity, aerosols, and temperature gradients vary significantly. Key technical hurdles include:

Turbulence-induced phase distortion: Leading to signal fading or loss of coherence.
Aperture limitations: Larger telescopes improve gain but are more susceptible to misalignment.
Slew rate constraints: For tracking fast-moving LEO satellites across the sky within seconds.
Spectral filtering and background light rejection: Especially during daylight operations near the sun’s path.

Cailabs claims its MPLC-based solution mitigates many of these issues by enabling real-time correction of incoming wavefronts before they reach the detector array—essentially “pre-cleaning” the beam path at the physical layer rather than relying solely on digital post-processing.

Toward Operational Deployment

The SES-Cailabs trials are expected to run through late 2024 at selected test sites in Europe. While no specific orbital assets were named, it is likely that both simulated sources and live satellite passes will be used during validation campaigns. If successful, SES could begin integrating operational optical ground terminals into its infrastructure by mid-decade.

This move would position SES among a growing cohort of operators—including Telesat, Inmarsat/Viasat, Airbus OneWeb Satellites, and Amazon Kuiper—investing in hybrid RF-optical architectures as part of their next-generation space network strategies. In parallel, defense agencies such as DARPA and ESA have also launched programs exploring inter-satellite laser mesh networks with terrestrial optical downlink nodes as key enablers.