In a significant milestone for secure naval communications, NATO recently validated the POLARIS optical communication system during an exercise involving two Portuguese Navy frigates. The test showcased a covert laser-based link that remained undetectable to conventional electronic surveillance systems—underscoring the potential of free-space optical (FSO) communications for future maritime operations.
POLARIS: A Stealth-Capable Optical Communication System
Developed under the European Defence Fund (EDF) and supported by NATO Science and Technology Organization (STO), POLARIS (Positioning and Optical Link for Advanced Reliable Integrated Services) is a next-generation free-space optical communication (FSOC) system. It leverages narrow-beam laser transmissions to enable high-bandwidth data exchange between mobile platforms while minimizing electromagnetic signature.
The core advantage of POLARIS lies in its ability to provide line-of-sight communications at gigabit-per-second rates without emitting detectable RF signals. This makes it inherently resistant to jamming and interception—key attributes for contested environments where electronic warfare and signal intelligence (SIGINT) threats are prevalent.
The system supports dynamic beam steering using gimbal-mounted optics and real-time tracking algorithms to maintain alignment between moving platforms such as ships or UAVs. It is designed for integration into existing C4ISR architectures via standard interfaces.
NATO Exercise Demonstration with Portuguese Frigates
The recent validation occurred during a NATO-led maritime interoperability exercise off the coast of Portugal in late September 2025. Two Portuguese Navy Vasco da Gama-class frigates were equipped with prototype POLARIS terminals mounted on stabilized platforms atop their superstructures.
According to official statements from the Portuguese Navy and participating defense contractors—including GMV Innovating Solutions and Thales Alenia Space—the test successfully established a bidirectional optical link over several kilometers of open sea. The link maintained stable throughput even under moderate sea states and platform motion.
Critically, SIGINT teams deployed aboard nearby vessels confirmed that no detectable RF emissions were observed during the test window—validating one of POLARIS’s key promises: operational stealth in the electromagnetic domain.
Operational Implications for Naval C4ISR
The successful demonstration has far-reaching implications for future naval command-and-control architectures. In high-threat environments where adversaries employ advanced EW capabilities or deny spectrum access through jamming/spoofing, FSOC systems like POLARIS offer an alternative path for resilient data exchange.
- Secure Inter-ship Networking: Enables encrypted broadband links without exposing RF signatures.
- Spectrum Independence: Reduces reliance on congested or contested radio frequencies.
- Low Probability of Intercept/Detection (LPI/LPD): Enhances survivability against SIGINT-equipped adversaries.
- C4ISR Integration: Supports real-time ISR sharing across task groups without compromising EMCON protocols.
This capability aligns with NATO’s broader push toward Multi-Domain Operations (MDO), where seamless information flow across air, land, sea, space, and cyber domains is critical. By enabling covert high-speed data links between surface assets—and potentially airborne or spaceborne nodes—POLARIS could serve as a backbone technology within future federated sensor-to-shooter networks.
Technical Challenges and Future Development
While promising, FSOC systems like POLARIS face several technical hurdles before widespread deployment:
- Line-of-Sight Limitations: Requires direct visibility between nodes; obstructed paths degrade performance or block signal entirely.
- Atmospheric Conditions: Fog, rain, or heavy sea spray can attenuate laser signals significantly—requiring adaptive power control or hybrid fallback mechanisms (e.g., RF redundancy).
- Aiming Precision: Maintaining sub-milliradian beam alignment between moving ships demands advanced stabilization and tracking algorithms.
The current trials are part of Phase II development under EDF funding. Future iterations will focus on increasing range (>10 km), improving robustness under adverse weather conditions via adaptive optics or wavelength diversity techniques, and miniaturizing terminals for deployment on smaller vessels or UAVs. Integration with satellite-based FSOC constellations is also being explored to extend beyond-line-of-sight capabilities globally.
NATO’s Strategic Context: Hardening EMCON Resilience
NATO navies increasingly recognize that traditional RF-based comms are vulnerable in peer conflict scenarios involving EW-saturated theaters such as the Baltic Sea or Indo-Pacific chokepoints. Russia’s use of GPS jamming in Ukraine and China’s development of long-range SIGINT platforms have underscored this vulnerability.
Pursuing alternative comms pathways—including FSOC—is part of broader EMCON resilience strategies aimed at ensuring force coherence even when GPS/RF networks are denied or compromised. In this context, POLARIS may complement other stealthy comms initiatives such as quantum key distribution (QKD), directional microwave links, and ultra-narrowband burst transmissions over HF/VLF bands.
