Formed in 2020, Phlux Technology is a spin out from Sheffield University and the company has developed a new class of infrared sensors that play a critical role in sending large amounts of data at a high speed, over optical links. These sensors are used to detect light and then convert these optical signals into electrical currents.
This new class of affordable infrared sensor, with significantly better performance than current sensors and based on 1550nm infrared sensor technology, are Noiseless InGaAs Avalanche Photodiodes (APDs) and they could have a revolutionary impact on a wide range of different applications.
The company was founded by Ben White, who is CEO, and Professors Jo Shien Ng and Chee Hing Tan, who met at the University of Sheffield while researching innovative semiconductor materials and devices for infrared detection.
Its new family of avalanche photodiodes, named Aura, was launched earlier this year and are constructed from modified InGaAs, with the addition of an antimony alloy. These sensors can amplify even the smallest signals and can even identify weaker secondary pulses, according to White.
White was always interested in electronics and engineering and was lucky enough to be educated at one of the few schools in the UK that taught electronics.
“I was certainly fortunate and had one of those inspirational teachers who encouraged me to take my studies further. I ended up at Sheffield University, which is one of the world’s leading centres for III-V semiconductor research.”
With a PhD from Sheffield, White then worked with a multi-disciplinary team of researchers. He published several papers on the development of new materials and ultimately this led to the discovery of an alloy composition of antimony that the team found exhibited a variety of unique electron properties including very low-noise behaviour that could be used to create a more efficient detector.
“That research and the contacts I made led to Phlux Technology,” explained White.
Running a business
White is very open and honest about the challenges of turning that academic research into a commercial proposition.
“Our initial focus was on developing the technology, addressing technical barriers and working to de-risk the manufacturing process,” he explained. “The launch of Aura is testament to that hard work, and we now have several new lines under development.
“But commercial success is never a given and that transition from academia to a business was never assured, but that journey was made a lot easier by having David Crisp on board,” said White.
Crisp, who is now the company’s chairman, had spent many years starting and running venture capital backed high-tech companies both in the UK and California. His last venture, Aveillant, a radar technology company, was acquired by Thales.
“David brought considerable commercial experience and acumen to the business and as a mentor to me he’s made a big difference,” said White. “I think a lot of interesting research can be disconnected from the market. While Blue Sky research is vital, I think the real magic occurs when you apply and commercialise that knowledge.
“It’s not just about working hard, either. David brought discipline to the process of creating and running a business, reassurance too, and the ability to have a conversation with investors.
“Our ambition from the get-go was to commercialise our research and become a product company,” said White. “We wanted to create the best detectors in the world.”
Unlike many start-ups Phlux was set up after years of research into the basic material that underpins the company’s photodiodes but also into the commercial possibilities of the technology.
“In terms of commercialising that research I was able to use some Innovate UK funding to travel to the US to talk to prospective customers. It was a networking trip that lasted three months and at the end of which it was obvious that there was a real demand for what we were working on.”
Infrared sensors have many diverse applications, from industrial robotics to satellite communications and Phlux is currently working with Airbus Defence and Space, and the University of Sheffield on a project to build more efficient free space optical communications (FSOC) satellite terminals.
“The project’s medium-term goal is to achieve reliable 2.5 Gbps communications with Low Earth Orbit (LEO) satellites at the 1550 nm wavelength. These satellites orbit the earth at heights of up to 2000 km. A longer-term aim is to produce links that will operate at 10 Gbps,” explained White, “and our APDs are at the heart of the project.”
This project also demonstrates the potential of the company’s technology which is truly huge.
According to White, the detectors in use today haven’t evolved much in the last 25 years and that’s a problem for many new applications.
“Companies want much improved levels of performance and what differentiates us from our competitors producing detectors for 1,550 nm is the addition of an antimony alloy to the compound semiconductor during manufacturing. That delivers a 12× better performance, uses less power, is smaller and reduces the bill-of-material cost,” according to White.
This will be of particular use to the growing adoption of LiDAR for automotive applications where many companies are focused on the 905 nm wavelength, where it’s possible to use cheap gallium arsenide lasers and low-cost silicon detectors.
“Those devices, however, don’t meet the growing performance requirements of end customers,” claimed White and that’s why Phlux has focused on the 1,550-nm wavelength. With its high-sensitivity Aura InGaAs photodiodes it’s possible to use low-cost lasers, which means the whole system is more effective while being cheaper.
The higher sensitivity means that the laser range finder can operate at up to a 50% greater distance, for a given optical power, simply by replacing the existing APD with a Noiseless InGaAs equivalent. The latter is a drop-in substitute. Turning down the power of the laser diode will reduce the instrument’s range but that will then result in longer battery life.
“Our focus on the detectors means that we’re simply rebalancing the design trade-offs,” explained White.
Both the automotive and communications markets are critical to Phlux going forward but both bring challenges whether in terms of competition, the need to qualify devices or simply scaling up the company’s manufacturing and testing capabilities.
But Phlux is making progress and recently achieved a ISO 9001:2015 certification which has demonstrated its commitment to quality in the development of its APD infrared sensors and in its production processes, positioning it as a trusted partner in the photonics industry.
“We need to be careful when it comes to the markets we target,” White admitted, “but we do have some significant advantages. We can be quick when it comes to decision making. We can offer rapid prototyping and design iterations using Sheffield University’s clean rooms which can be done in a matter of weeks, not months, and we also have the ability to get a product to market quickly.
“Going forward, we’ve recently made some strategic leadership appointments and have relocated to larger premises. We’ve proven our technology and are now developing products for high growth industries,” White explained.
“We will still need to maintain our focus when it comes to what we look to develop, and we need to maintain the pace of delivery. But, we are delivering a step change in performance when it comes to infrared sensors and it’s exciting that it is happening here in the UK," added White.
" We’ve certainly got global ambitions for our technology and when you think that hundreds of millions of sensors will be sold by 2030, we are well placed to achieve a sizeable share of that market.
“I believe that in ten years’ time how we make these sensors could well be the manufacturing benchmark for all infrared sensors.”
