We live in a connected world. We can work, talk, navigate or entertain thanks to an elaborate network of technologies around the globe.
The fast pace of our society demands more than the maintenance of this connectivity. What we need and strive for is near-real-time connections that are affordable, secure and globally available.
FSO Instruments has developed and is working on a number of technologies enabling high-speed laser links between space, air and ground terminals to take the next step towards the future.
FSO & TNO: overview of the technology (video)
Cutting edge research
Laser communication systems need to become more compact and affordable. This is of particular interest for satellite constellations in Low-Earth-Orbit (LEO).
Such constellations will be able to deliver larger amounts of data to us – not only due to the quantity of satellites, but due to the higher bandwidth that laser communication provides in comparison to many radio frequency technologies.
CubeCat is a fully integrated plug-and-play laser communication terminal for small satellites in LEO. It allows for high-speed data links from satellite to Earth and vice versa. CubeCat has been developed within FSO Instruments. It is going to be demonstrated in space in the second quarter of 2021.
An optical bench forms the backbone of all optical and opto-mechatronic components within a laser communication system. Beam conditioning, splitting and shaping optics are all included within the optical bench to direct the optical beams towards the targeted components. It forms the bridge between the components like the Fine Steering Mirror, Sensors, Controllers and Telescope.
Fine Steering Mirror
Sensors onboard a satellite measure the incoming angle of received light from a partnering laser terminal. The FSM uses this information to correct for high-frequency misalignments, since the satellite’s pointing accuracy is often not precise enough for this.
A second FSM typically provides information on the Point Ahead Angle (PAA). This enables the laser communication terminal to compensate for the “time of flight” – or the time it takes for the laser beam to arrive at the receiving end.
The coarse pointing assembly acts as a tip-tilt mirror within a laser communication terminal. It allows the satellite to point to its target without the need to change the attitude of the satellite. Using a CPA has the advantage of reducing manoeuvres of satellites and having a nearly uninterrupted data stream.
A range of CPAs for different applications is currently under development within FSO Instruments.
Also the airborne sector is looking into connectivity using laser solutions – be it for navigation, weather or tactical data. Laser communication links between aircraft will change the way we manage air traffic or provide entertainment and internet aboard planes.
An Optical Bench for aircraft enables exchange, fast-forward and global dissemination of data via laser beams while in flight. This near-real-time connectivity will benefit crew and passengers.
Such solutions are also of interest to drones used for monitoring or scouting of remote areas in large swarms. Data transmission to and from drones will increase in bandwidth and speed thanks to laser communication – giving operators the possibility to base their decisions and action plans on comprehensive sets of data in near-real-time.
Fine Steering Mirror
Miniaturised Fine Steering Mirror find applications also on aircraft. Similar to its space applications, the pointing accuracy of an aircraft is often not enough to point the laser beam at a ground station, another moving aircraft or at a spacecraft. The FSM uses sensor data to correct for misalignments in the pointing of the air terminal.
Ground Station Products
FSO Instruments and TNO are currently working on a demonstrator of a fully integrated Optical Ground Station made in the Netherlands. It will be built in the Hague and demonstrated in Q2 2021.
In the future, FSO Instruments will provide key components to enable three major types of Optical Ground Stations: Gigabit class Direct-to-Earth communication, for example with satellites in LEO; Terrabit class Feeder Links, to disseminate uninterrupted data to end users via Geostationary satellites, for example for streaming or crucial applications; and Quantum key distribution, for the security and financial sector.
An optical bench forms the backbone the optical ground station. It forms the bridge between the components like the Deformable Mirror, Fine Steering Mirror, Sensors, Controllers and the Telescope.
Such an Optical Bench for the Optical Ground Station is still under development and will be commercialised through the FSO Instruments consortium in due course.
The Gigabit Detector is the receiver within an optical ground station. It receives and converts data contained in laser beams into a digital bitstream, ready to be processed by a high-speed data handling system.
Within the Optical Ground Station, a Modem integrates this receiver with other components. The TNO’s OGS demonstrator modem will be supplied by a Dutch company, supporting FSO Instruments.
Our atmosphere can interrupt the reception of laser communication, e.g. through clouds, or disturb it considerably. While we do not have a solution against clouds yet, there is one for atmospheric disturbances.
The Deformable Mirror developed within FSO Instruments uses a unique new technology, based on electromagnetic actuators to compensate for these disturbances.