Jean-François Morizur, Founder and CEO of Cailabs, explains how the laser tech intended for quantum computing is proliferating in space-to-ground comms
Jean-François Morizur is founder and CEO of Cailabs, headquartered in Rennes, Brittany, France (pictured). Back in 2008/9, he was studying for a PhD and with his supervisor, experimenting with light and how to change its shape. The intended use was for quantum optics for a quantum computer. Instead they patented what he calls “nuggets” discovered through the research but says, “Honestly, we didn’t know what to do with it”.
He left the physics lab and joined Boston Consulting Group (BCG) in September 2011, but shortly after his former supervisor contacted him to say Lucent was interested in using their patent in telecoms for fibre optics. He left BGC, with his boss’ blessing, and set up Cailabs.
In 2013, the company began working on how different light shapes could each carry a data stream to cram more data into fibre optics. The tech is now known as spatial multiplexing, spatial division multiplexing (SDM) and sometimes spatial video multiplexing, and works on top of dense wave division multiplexing (DWDM) which separates out different wavelengths.
Optical for space-to-ground comms
In 2018, a Japanese client mentioned SDM could be useful for space-to-ground optical comms. Morizur explains, “This is because the technology can deal with one of the most vexing problems of space-to-ground optical, the effect of the atmosphere on lasers – the atmosphere changes the shape of light as it passes through, in a fluctuating way. Dealing with that efficiently is very tough.”
He says, “It’s thanks to the tech we developed, but also to very good engineering – we’ve got a lot of people working on it – and our focus from the beginning.” Work began at the component level around 2018 but then Cailabs started working on optical ground station themselves and the full systems since 2020 when it was contracted by the French Ministry of Defence.
Starlink and optical comms in space
This has turned out to be a great business to be in, given the rise of Starlink and the development of device-to-device (D2D) comms. Hindsight is a wonderful thing: Morizur notes that back in 2018, optical communication for space was considered “science fiction” and way too expensive.
He continues, “It’s thanks to the tech we developed, but also to very good engineering – we’ve got a lot of people working on it – our focus from the beginning.” It helped a lot, he says, “When SpaceX said, ‘Well, my whole constellation is only working because I’m using optical communication between satellites’, and they’ve got 9,000 optical terminals in space.
“Then everybody realised that if you want to design a state of the art constellation, you need to have optical between satellites at the minimum, and if you want to benefit from the future of the space economy, you need to have optical to the ground also.”
Are LEOs the lion’s share of optical?
Morizur says that although “There’s much more going on with LEOs and it’s probably more mature, but we’re getting there for GEOs and MEOs. I wouldn’t discount them. They will have different use cases, different architectures, different visions of what future architecture looks like.”
“I’d say [multi-orbit constellations] are a very safe bet – MEO satellites gives coverage as good as LEOs, but with far fewer satellites. The latency is higher, but that might not matter, depending on what you want to do,” Morizur adds. “ In future, we’ll have all the different layers. Starlink launches thousands and thousands of satellite and is amazing, but many people don’t have the money or rockets to launch so many.”
Is it radio versus optical?
He muses, “D2D – user terminals – is a radio game and I see as starting antennas too as a very big radio game for a very long time.” Optical is a better option though for use cases like connecting a military base to a satellite, for example, “where you want something that cannot be detected, cannot be intercepted” which also means it can’t be jammed.
Optical makes jamming harder because “the optical terminal on the satellite is so small and the spot it covers on the Earth’s surface is tens of metres compared with radio has a coverage area of maybe 40km. The laser beam is kept as narrow as possible, so it’s a very small target and if [the interceptors] are that close, they’ve already invaded the base,” Morizur says wryly.
This is important as jamming is becoming an increasingly serious and prevalent problem. For example, Russia has been accused of jamming the space-based Global Navigation Satellite System (GNSS often referred to as GPS) across Europe. Moscow claims defensive jamming is used to protect infrastructure and cities from Ukrainian drone strikes, but Western officials and NATO leaders often describe it as part of a deliberate, aggressive hybrid campaign.
There was also a recent case of a people believed to be Chinese spies renting an Airbnb close to Toulouse to listen in to satellite traffic at the Issus-Aussaguel ground station which communicates with satellites used by the French military and intelligence. There is another major airbase in that region, at Bordeaux-Mérignac, and defence firms like Airbus, Thales and Dassault all have installations in the area.
Encryption is an option for radio links but Morizur says this is far more complex in space than for mobile phones and computers.
Spectrum, capacity and cost
Another of optical’s strengths is superior capacity. He says. “If I’m the government and I want to bring down very rich data from my observation satellite, I probably want to do it very fast because I want to act on it very fast, but there’s limited spectrum available for Earth observation satellites which is controlled by regulation.”
On the other hand, “The cost of [optical] equipment is similar to radio but you have 20x or 100x capability bump, depending on whether you own the spectrum,” he states. “If you do own the spectrum, using antennas you can achieve relatively high throughputs but owning that spectrum costs a lot of money and if you’re invested in it, you’re going to use it and feel that radio is safer even though optical is cheaper per bit per second.”
That argument doesn’t hold for a new entrant or if an organisation runs out of spectrum. Then, he continues, “the question is whether to pay another €10 billion to buy [more] – and it might get even more expensive in future.
“One option is to use spectrum for users and keep optical for the organisation’s own operations although it depends a lot on the context. There’s also the middle part – the possibility of using optical for the main satellite communication gateways, depending on whether you’re running a constellation that owns spectrum or not.”
Reducing latency, processing in space?
Could optical reduce latency? “The quick answer is no, but it depends on the cause of the latency,” he says. “Latency is governed by the speed of light which is the same for radio waves and lasers. But if latency is the result of a bottleneck – say you are buffering data and a big amount must come through a tiny hose – optical can definitely help.”
“It’s not that one better than the other so much as business choices. Generally the idea is to augment radio rather than replace it,” he explains.
What about the potential of embedding AI in satellites? Morizur says he is asked about this a lot. One idea is that the satellite could process the data onboard – Elon Musk claiming data centres will be orbiting the Earth as soon as next year. On a slightly less ambitious tangent, processing onboard the satellite could allow it to send very short messages back to Earth to convey key data, like the exact location of tanks.
Clearly this would minimise traffic and therefore help latency, but he says partners in the intelligence community don’t want to go down that route. They want to control how “data is processed so they can understand, track it, test it and audit it because they make impactful decisions based on it,” he explains.
AI’s impact
Even so, Morizur believes satellites will get smarter and smarter because it will improve reaction time. “Even if it’s just one satellite texting the next one to say, ‘I’ve seen something moving there, take another picture’,” he says. “We’ll still need computers processing data on the ground and people checking the computers. You can process routine stuff, most of the time, with computers, but sometimes you need access to raw data to check it.”
He acknowledges that AI will be essential to extract the value from huge volumes of data and that “AI will make an impact in our field,” but adds, “I sometimes think AI is a bit overstated.”
