DWDM

The optical transceiver market is expected to double in size by 2025, and coherent optical technology has come a long way over the past decade to become more accessible and thus have a greater impact on this market. When Nortel (later Ciena) introduced the first commercial coherent transponder in 2008, the device was a bulky, expensive line card with discrete components distributed on multiple circuit boards.

Recently, EFFECT Photonics and Aston University announced that they would collaborate as part of the newly formed Royal Academy of Engineering Research Chair in Highly Integrated Coherent Optical Fibre Communications.

To learn more about this industry/academic partnership, we interviewed the three lead researchers in this project: Prof. Wladek Forysiak, Dr. Ian Phillips, and Dr. Stylianos Sygletos.

Tell us a little more about yourself and the team

Wladek: My background goes back almost to the start of the Aston Institute of Photonics Technology (AIPT). AIPT was formed by a couple of guys who came out of British Telecom and what was then part of the GEC Telecom Company. The institute has deep industrial roots, and hence the people who work at AIPT often like to participate in projects close to the industry with relatively short timescales. I joined the institute as a post-doc and then subsequently became an academic staff member.

Around 2000, I left alongside five others for a “virtual startup” with the Marconi company, and we formed an entity called Marconi Solstis. At that time, we developed a record-breaking terrestrial ultra long haul system, and we installed our first system in Australia, linking the cities of Perth and Adelaide. Marconi then morphed into Ericsson, and I stayed there for another six to seven years.

In 2010, I moved to Oclaro (now Lumentum), which does somewhat similar technology to what’s being developed by EFFECT Photonics on their integrated indium phosphide platform. I spent three or four years there before returning to academic life at Aston. As for the team, we have funding for three full-time Ph.D. students we’re currently working to recruit. They will be the cement, the foundation of our project.

Ian: I’m of a similar background to Wladek. My expertise is in transceivers, especially characterization and design. I completed my Ph.D. at Aston in 1997 in optical signal processing. British Telecom (BT) sponsored the project, and I worked there for a year after my Ph.D. Corning subsequently purchased the BT Photonics Lab in 2000, and I stayed there for another year. Afterward, I moved to Marconi Solstis with Wladek and stayed there until 2010, when Ericsson closed the site. I then worked in Italy for two years, transferring some system knowledge to the Ericsson research group there, and finally, I joined Aston in 2012.

Stylianos: I completed my Ph.D. at the National Technical University of Athens in 2006, focusing on the physical layer modeling of optical communication systems. I worked for a year at Athens Information Technology (i.e., a research center of Intracom, the largest telecom system provider in Greece). Between 2007 and 2009, I moved for a post-doc position in the Karlsruhe Institute of Technology, working with Juerg Leuthold to model quantum-dot semiconductor optical amplifiers.

I then moved to the Tyndall National Institute in Ireland in 2009 to join the group of Andrew Ellis. I focused on the design and experimental implementation of phase-sensitive amplifiers and optical phase-locking solutions for these amplifiers.

After 2012, I joined AIPT as a research fellow, where my research interests eventually changed to digital signal processing and machine learning. I want to apply machine learning to the physical layer of optical communication systems. I’m now the director of two Master’s programs at Aston: the Smart Telecom and Sensing Networks (SMARTNET) and the Erasmus Mundus Photonic Integration and Networks (PIXNET), in collaboration with different universities in Europe and Japan.

What attracted you to collaborate with EFFECT Photonics?

Wladek: This project came about through a conversation between James (EFFECT Photonics’ CEO) and myself where he said, “Well, I’m interested in growing research activities to enhance our systems capability, and I have confidence in the experience of you and the Aston team”. So I said to him that one way to build a long-term relationship between a company and a university is through Ph.D. studentships.

AIPT is very much about doing applied research, and James was very much about the value of user-directed research that is close to the market and based on real-world situations. So he and I shared that vision around the partnership.

Another reason was, of course, that EFFECT Photonics has technology complementary to ours. EFFECT can be a source of advanced technology for us to build the best experiments that compete with the best in the world. Our competition is in the advanced labs of Japan, the US, and other areas in Europe, and having access to great components is key to matching their capabilities.

We also found attractive the ambition and drive of a startup company and its ability to make quick decisions. When I reached out to James with ideas, I could get an immediate yes or no answer, often on the call, for authorization.

Ian: James explained to us really well what EFFECT Photonics was doing, its ambitions, and how it aligned with our work. When we visited the facility in Brixham and were shown around the labs, it was all indicative of a company that wanted to get things done quickly, and hopefully, we can help them in that process.

Stylianos: On top of what Wladek already mentioned, it’s great to work with a startup that is more open to testing new technologies. I’m passionate about machine learning, and the prospect of applying machine learning algorithms to EFFECT Photonics’ novel technology platform is very exciting. I feel like there is an opportunity to make a big impact.

In what ways do the facilities of Aston University complement what EFFECT Photonics has?

Wladek: EFFECT Photonics develops advanced components that interest people like us working on optical communication systems and networks. We’re used to thinking about integrating these advanced components into our systems and getting the maximum capacity from point A to B.

We have a history of 30 years with optical fiber transmission, so we have all the necessary facilities for system modeling and testing. Stelios also brings to the party his expertise in DSP software, which is also critical to what EFFECT Photonics may do in the future. 

Ian: We also see our job as training the Ph.D. students to pass on our knowledge of system design and how that reflects in EFFECT Photonics’ transceiver design. We want to train the students and get them to creatively and effectively use the components.

Stylianos: It depends on how the project goes, but we can even develop device models of EFFECT Photonics units and identify the device parameters that can meet network and system-level targets. We can even combine it with machine learning for extra optimization of those parameters.

What are some of the main challenges you hope to address?

Wladek: Looking for a greener future is a big challenge in optical comms. We’ve all witnessed it in the last couple of years with the pandemic. We need greater network capacity but also cheaper and greener. We cannot let that demand for capacity just be the same old technology since power consumption would go up and up and up.

The challenges are similar to what they’ve always been, in a way, but even more acute. And we need to do it all without really spending more money. Nobody wants to pay more for their comms at the end of the day.

We should also go in other directions to increase the capacity. For example, EFFECT Photonics’ current components are made for the optical C-band, but people in long-haul and other areas are looking at creating multiband components that can also operate in the L-band. We’ve also got projects currently looking at the S-band and shorter wavelengths. Researchers are also looking at different fibre structures to carry more and more signals.

At the same time, there’s an industry drive never to pay for more. Ultimately, that mindset has driven even more technical innovation. Capacity has gone up, but the price has gone down. It’s a relentless game, and everyone keeps saying there’s going to be a point at which we don’t need any more capacity, but if it’s there, we always find ways of using it.

Ian: One key challenge many companies are working on is increasing the baud rate, which is quite a technical problem. If you increase the baud rate, you increase the channel capacity too. It was stuck at around 28 GBaud for a long time, and now it’s going up 64 and even 100 GBaud.

Stylianos: I want to mention how important is network optimization to improve performance and reduce power consumption, which would lead to greener networks.

Network operators need to maintain large performance margins to secure a robust operation in different network conditions. In practice, however, these margins mean more power consumption. Ideally, you would like to reduce those margins by a more efficient design of your system and performance that can adapt to the different conditions. We can achieve these goals through machine learning.

This requires solutions for multi-objective optimization. For example, we are not just interested in designing the transmitter subsystem, but we want to see how transmitter performance is connected to network-level performance, as measured by throughput and power consumption. This is a complex problem that involves different layers of the system.

Takeaways

Moving towards a higher-capacity and greener future requires strong collaboration between academic and industrial partners with shared goals. EFFECT Photonics and Aston University share a vision around this greener future and the value of applied research.

This joint project will unite EFFECT Photonics’ component development expertise with Aston’s expertise in optical fiber transmission modeling, testing, and network optimization through machine learning. This union can enable faster, more affordable, and sustainable coherent products that give greater bandwidth to a greener future.

As Wladek mentioned in the interview, this joint project is looking for three PhD students to drive it forward, with the positions available to start in March, July, or October 2022. If you are interested in applying or know someone who might be interested, please visit the following link: https://jobs.aston.ac.uk/Vacancy.aspx?ref=R210549 .