Speed of light
Laser based communications operates at many times the speed of RF communications links. Just as fibre broadband has transformed our home and working environments, Free Space Optical Communication’s promises to transform the military battlespace. Many military platforms have RF data links that operate at the speed of an old-fashioned modem. Optical communications is the equivalent of having fibre to your doorstep, offering multi-Gigabyte data links. As sensors and the resulting data volumes increase exponentially, FSOC provides a scalable means by which to transport the data that will deliver information advantage.
Whilst not intended to replace RF communication there are scenarios where a direct and secure transfer of data makes more sense and optical is best placed to complement those RF technologies as part of an overall architecture.
RF communications systems rely upon broadcasting data widely over a pre-determined frequency, and encrypting it to prevent interception. Free Space Optical Communications is almost impossible to intercept or detect, as the laser beam travels directly from one platform to another over a very narrow path. Interception would require an adversary to be physically present in the path of the beam – something that is extremely difficult to achieve.
In modern conflicts adversaries are increasingly able to conduct precision targeting using RF communications signatures. By utilising optical communications the, overall RF signature of forces is vastly reduced. This reduced signature greatly increases the survivability of blue forces by limiting the ability of an adversary to intercept, jam, spoof, direction find and strike.
As the RF spectrum becomes increasingly congested, free space optical communications (FSOC) offers an alternative. Not only does it offer greater bandwidth and security it avoids spectrum conflict. Unlike RF, the laser beam is highly directional and different links do not interfere with each other.
Improving Data Interoperability
Since optical datalinks do not use the RF spectrum not only is spectrum management easier with allies but interoperability is easier to achieve. As FSOC technology has an inherently low probability of detection or intercept, the need for complex encryption/decryption is reduced. This means that reliance upon nationally-sovereign cryptography is lessened and interoperability of data exchange between allies can be increased.
Combining ISR Capability with Optical Communications
In addition to the optical communications inspired by the principles of software-defined radio, FOSC systems can switch between communications mode and sensing functions. This provides unprecedented multi-functionality, particularly critical on military platforms where size weight and power constraints are often a limit to performance.
Examples of the ISR functions incorporated optical communications are 3D Mapping and long range target ID using vibrometry, in addition to the capabilities granted from an EO/IR payload capability housing the FSOC system.