Created April 5, 2023
Technical Features


Making fibre optic communications sustainable is vital to reducing the industry’s contribution to the reduction of global carbon emissions. The opportunities for carbon reduction across the industry are myriad, including supply chain management to component development and the switch to renewable energy, to name but a few. Peter Dykes looks at three examples of how some companies are approaching the challenge to become more sustainable, and how best to measure progress.




It is generally accepted that the use of fibre optics is inherently more environmentally friendly than other network technologies for a variety of reasons, but we need to fully exploit the properties of the medium, argues Kelvin Hagebeuk, Marketing Manager for Test and Measurement at Yokogawa Europe.

He says, “The world is facing many sustainability challenges, with climate change requiring us to make more efficient use of energy that is produced from greener sources. As a leading supplier of test equipment, Yokogawa knows that the Test and Measurement industry can help make the difference we all need to see. An example is the growing use of data from the Internet of Things, in cloud computing services, video broadcasting and conferencing, and the rise in access to mobile broadband – the Royal Society has estimated that digital technologies could be responsible for nearly 6% of greenhouse gas emissions. To avoid building more network infrastructure, which leads to more emissions in production and installation, we need to make better use of the fibre network we already have.”

This, he explains, means getting more data through each ‘pipe’, using DWDM in which channels become ever more closely spaced. This makes it more difficult to separate the individual channels in the WDM analysis on an Optical Spectrum Analyzer or OSA.

“To meet this need, Yokogawa has produced a new range of OSAs with unprecedented resolution, down to 5 picometers (pm), allowing optical signals in close proximity to be clearly separated and accurately measured. With a wavelength range of 1200 to 1650 nm, as well as the ability to alter the wavelength resolution from 5 pm to 2 nm, the new OSA can support a wide range of applications, from narrowband peak/notch measurements to wideband spectral measurements,” he says.


“As well as making their telecom systems more efficient by boosting data capacity,” says Hagebeuk, “telecom operators are also looking to improve their environmental credentials by using renewable energy sources to power networks and data centres. Transport is also moving to electric power, which is increasingly generated from renewable sources and Yokogawa’s experience in providing precision measurement solutions for transport and renewable energy industries is also bringing benefits to telecoms. Yokogawa’s solutions allow our customers to expedite the development of the next generation of sustainable technology and innovation. One major challenge is that as power systems become more complex, analysing them becomes increasingly difficult. New electric power sources such as fuel cells and high-density batteries make new demands on test and measurement equipment. Yokogawa is meeting these needs by developing Precision Power Measurement solutions. Combined with our high-speed data acquisition instruments such as the DL950 ScopeCorder, developers have a complete solution to evaluate the efficiency and performance of new and existing power technologies.”

He says that developers of these systems also need a supplier that can integrate best- in-class hardware with advanced software solutions. Yokogawa’s experience of power measurements for transport and renewable sources such as wind turbines has led to the development of an integrated measurement platform that makes it easier to see results from different instruments.

“This solutions experience is now benefitting power technologies used in telecommunications, helping developers improve their efficiency and performance,” he concludes.


On the subject of energy, Coherent launched a major renewable electricity procurement program approximately three years ago as part of its commitment to reduce the environmental impact of its manufacturing operations. The company has sourced renewable electricity for dozens of its facilities worldwide at every level of its vertically integrated, global manufacturing base. For example, when a customer purchases a ROADM product from Coherent, all of the following manufacturing operations are now powered with 100% renewable electricity:

  • Semiconductor lasers (Switzerland)
  • Thermoelectric coolers (Texas)
  • Tuneable optical filters (Massachusetts)
  • Wavelength selective switches (WSS) (California)
  • Wavelength division multiplexing (WDM) filters (California)
  • Optical components (Vietnam)
  • Pump laser subassemblies (the Philippines)
  • Pump laser packaging and optical assembly (China)

Richard Marino, Director of Sustainability, Coherent explains, “We are on track to have 100% renewable electricity for all of our operations in the Networking Segment of Coherent by 2025, approximately 273 million kWh per year. This includes our factories as well as our smaller locations for engineering, R&D, and sales offices. All Coherent sites, large and small, are included in this effort. This represents a very significant reduction of our environmental footprint, given that electricity usage accounts for about 90% of our total Scope 1 and Scope 2 greenhouse gas emissions.”

He continues, “In addition to renewable energy contracts, we have installed an on-site solar energy system at our facility in Vietnam, and we are evaluating similar installations at other locations. Our engineering and facilities teams have achieved a cumulative energy savings of 10 million kWh per year through numerous energy efficiency projects. Our manufacturing and quality teams drive yield improvements on the production line that also correspond to reduced energy usage per unit produced, estimated at an additional 4 million kWh per year of energy savings.”

On future developments, Marino says, “We will be partnering with our suppliers to drive similar carbon reduction programs in our supply chain, starting in 2023. We are excited that several of our supply chain partners already have carbon reduction programs underway, and we want to recognise and reward their progress in this area. We will work with suppliers that are not as far along to initiate similar programs as we drive to decarbonise our supply chain. All of our stakeholders – customers, investors, employees, local communities, and the world at large – are counting on us to do our part to help reduce greenhouse gas emissions and mitigate climate change, and Coherent is up to the challenge.”


Apart from more efficient use of fibre and the switch to sustainable energy sources, the very evolution of optical technology is having significant knock-on effects for networks and their operators.

Helen Xenos, Senior Director of Portfolio Marketing at Ciena says, “There’s a lot that we can say about network sustainability, and it is a huge area of focus for us at Ciena as well as many of our customers. We’ve gone through the exercise of calculating the sustainability impacts of our coherent technology innovations and how it has helped our customers reduce greenhouse gases.”

She explains, “For example, we calculated the impact of the power and space efficiencies that have been achieved with each successive WaveLogic generation that we’ve introduced over the past 10 years, which has led to a reduction of 4.5 million metric tonnes of greenhouse gas emissions into the atmosphere. So, it’s pretty significant. This includes the impact of 18 months of WaveLogic 5 Extreme shipments. The reason why we are so focused on innovating from a coherent technology perspective, is that as bandwidth grows and increasing levels of capacity are deployed each year, early adoption of new technology becomes even more important, helping customers make faster progress towards their sustainability goals as they can deploy more capacity with less power and space. When you provide connectivity more efficiently, that gives you a bigger bang at the end of the day – it helps not only in reducing energy consumption, but also has the knock-on effect of reducing cooling and leasing costs– you can see how the benefits quickly add up.”


Obviously, different sectors of the industry will approach sustainability issues in specific ways, according to their place in the ecosystem and ways of measuring the success of their initiatives, meaning that it’s difficult to evaluate the carbon footprint of the industry as a whole. In an attempt to arrive at an overall picture of view of how the industry is performing, in Europe at least, the FTTH Council Europe is working on a plan to provide a common method of reporting across the fibre ecosystem.

Vincent Garnier, Director General, FTTH Council Europe explains, “We are starting a programme to help our members report their carbon footprint metrics and performance on the basis of comparable metrics. We would like to say, should you be a software vendor, a cable manufacturer or manufacturer of passive or active electronic equipment, a contractor, builder or an operator, we offer you the possibility to align on the way you report your carbon footprint. What we want to do is help all categories of player to talk together and be able to check and report on the progress of our industry holistically as we move forward. It’s ambitious, but I think if we don’t have common way of presenting our reports, we’re not going anywhere.”

He adds, “I know that some legislation at a higher level than purely our industry is also moving in that direction and that at some point, we will certainly be obliged to report for every organisation’s carbon footprint performance. There will be a standard, in exactly the same way you have accounting standard to report on your financial situation. We are taking this step to help and also to make sure that every single member of the Council is aware of this matter. It’s a very concrete step towards helping the industry progress with a lower carbon footprint.”

Garnier points out, “Carbon footprint is not only what you do yourself, but also what you generate indirectly, so you need to understand what is the carbon footprint of your supplier to be able to measure your own carbon footprint. By connecting people, we hope to also give to everyone the possibility to have a more accurate understanding of the real footprint because we will have possibility to integrate a more accurate carbon footprint measurement of all partners in the value chain.”

Left to right:

Kelvin Hagebeuk, Marketing Manager, Test & Measurement, Yokogawa Europe
Richard Marino, Director of Sustainability, Coherent.
Helen Xenos, Senior Director, Portfolio Marketing, Ciena.
Vincent Garnier Director General, FTTH Council Europe.

This article was first published in Optical Connections magazine, Spring 2023.


This article was written
by Peter Dykes

Peter Dykes is a independent telecoms and technology journalist who has over that last 30 years written for a wide range of B2B publications and companies. A former BT engineer, he specialises in networks and associated support systems. He is currently Editor of Optical Connections.