OFC 2025 industry reflections - Final Part
Gazettabyte has been asking industry figures for their thoughts after attending the OFC conference held in San Francisco.
In the final part, Arista’s Vijay Vusirikala and Andy Bechtolsheim, Chris Doerr of Aloe Semiconductor, Adtran’s Jörg-Peter Elbers, and Omdia’s Daryl Inniss share their learnings. Vusirikala, Doerr, and Elbers all participated in OFC’s excellent Rump Session.
Vijay Vusirikala, Distinguished Lead, AI Systems and Networks, and Andy Bechtolsheim, Chief Architect, at Arista Networks.
OFC 2025 wasn’t just another conference. The event felt like a significant momentum-gaining inflexion point, buzzing with an energy reminiscent of the Dot.com era optical boom.
This palpable excitement, reflected in record attendance and exhibitor numbers, was accentuated for the broader community by the context set at Nvidia’s GTC event held two weeks before OFC, highlighting the critical role optical technologies play in enabling next-generation AI infrastructure.
This year’s OFC moved beyond incremental updates, showcasing a convergence of foundational technologies and establishing optics not just as a supporting player but a core driver in the AI era. The scale of innovation directed towards AI-centric solutions – tackling power consumption, bandwidth density, and latency – was striking.
Key trends that stood out were as follows:
Lower Power Interconnect technologies
The overarching topic was the need for more power-efficient optics for high-bandwidth AI fabrics. Legacy data centre optics are impacting the number of GPUs that fit into a given data centre’s power envelope.
Three main strategies were presented to address the power issue.
First, whenever possible, use copper cables, which are far more reliable and cost less than optics. The limitation, of course, is copper’s reach, which at 200 gigabit-per-lane is about 1-2m for passive copper cables and 3-4m for active redriven copper cables.
Second, eliminate the traditional digital signal processor (DSP) and use linear interface optics, including Linear Pluggable Optics (LPO), Near Package Optics (NPO), and Co-Packaged Optics (CPO), all of which offer substantial (60%) power savings, lower latency, and higher reliability compared to traditional DSP solutions.
The biggest difference between linear pluggable optics and co-packaged optics is that linear pluggable optics retains the well-known operational advantages of pluggable modules: configurability, multi-vendor support, and easy field serviceability (hot-swapping at module level), compared to fixed optics like co-packaged optics, which require chassis-level RMAs (return materials authorisation). It remains to be seen whether co-packaged optics can overcome the serviceability issues.
Third, developments in a host of new technologies – advances in copper interconnects, microLED-based interconnects, and THz-RF-over-waveguides – promise even lower power consumption than current silicon photonics-based interconnect technologies.
We look forward to hearing more about these new technologies next year.
Transition from 200 gigabit-per-lambda to 400 gigabit-per-lambda
With the 200 gigabit-per-lambda optical generation just moving into volume production in 2025-26, attention has already turned to the advancement and challenges of 400 gigabit-per-lambda optical technologies for future high-speed data transmission, aiming towards 3,200 gigabit (8×400 gigabit) modules.
Several technical approaches for achieving 400 gigabit-per-lambda were discussed, including PAM-4 intensity modulation direct detection (IMDD), PAM-4 dual-polarisation, and optical time division multiplexing (OTDM). The technology choices here include indium phosphide, thin-film lithium niobate (TFLN), and silicon photonics, which are compared based on RF (radio frequency) loss, integration, cost, and high-volume readiness.
For 400 gigabit lambda optics, indium phosphide and thin-film lithium niobate are strong candidates, as silicon photonics will struggle with the high bandwidth.
At this point, it is impossible to predict which platform will emerge as the high-volume winner. Delivering power and cost-effective 400-gigabit lambda optics will require a concerted industry effort from optical component suppliers, connector suppliers, and test and measurement vendors.
Multi-core fibre
A new pain point in large AI data centres is the sheer number of fibre cables and their associated volume and weight. One way to solve this problem is to combine multiple fibre cores in a single fibre, starting initially with four cores, which would offer a 4:1 reduction in fibre count, bulk, and weight.
Hollow-core fibre
Innovation continues in the foundational fibre itself. Hollow-core fibre generated significant buzz, with its potential for lower latency and wider bandwidth attracting intense interest.
The maturing hollow-core fibre ecosystem, including cabling and interconnection progress, suggests deployments beyond niche applications like high-frequency trading may be approaching, reaching areas like distributed AI processing.
AI-driven network evolution
AI isn’t just driving network demand, it is increasingly becoming a network management tool.
Numerous demonstrations showcased AI/machine learning applications for network automation, traffic prediction, anomaly detection, predictive maintenance – e.g., analysing optical time-domain reflectometer (OTDR) traces, configuration management, and resource optimisation. This represents a fundamental shift towards more efficient, reliable, self-configuring, self-healing, and self-optimising networks.
Along with the many technical talks and tutorials, show floor demos, and customer and supplier meetings, OFC attendees also had a chance to combine technology with some light-hearted fun at the rump session.
This year’s topic was rebuilding global communication infrastructure after an alien invasion, and three teams came up with thought-provoking ideas for this theme.
Chris Doerr, CEO of Aloe Semiconductor
The best way to describe OFC 2025 is a giant Mars dust storm that raged for days. The swirling sand made it difficult to see anything clearly, and the sound was so loud you couldn’t think.
Acronyms ending in “O” were hitting you from all sides: LPO, LRO, NPO, CPO, OIO. The wind blew away sand that had buried old technologies, such as lithium niobate, electro-optic polymer, and indium-phosphide modulators, and they joined the fray.
Only now that the storm has somewhat subsided can we start piecing together what the future holds.
The main driver of the storm was, of course, artificial intelligence (AI) systems. AI requires a vast number of communication interconnects. Most interconnects, at least within a rack, are still copper. While copper keeps making incredible strides in density and reach, a fibre-optic interconnect takeover seems more and more inevitable.
The Nvidia announcements of co-packaged optics (CPO), which go beyond co-packaged optics and deserve a new name, such as optical input-output (OIO) or system-on-chip (SOC), created a great deal of excitement and rethinking. Nvidia employs a silicon interposer that significantly increases the electrical escape density and shortens the electrical links. This is important for the long-term evolution of AI computing.
The CPO/OIO/SOC doesn’t mean the end of pluggables. Pluggables still bring tremendous value with attributes such as time-to-market, ecosystem, replaceability, etc.
Most pluggables will still be fully retimed, but 100 gigabit-per-lane seems comfortable with linear pluggable optics (LPO), and 200 gigabit-per-lane is starting to accept linear receive optics (LRO).
For 200 gigabit per lane, electro-absorption modulated lasers (EMLs) and silicon photonics have comfortably taken the lead. However, for 400 gigabit per lane, which had two main demos on the show floor by Ciena and Marvell, many technologies are jockeying for position, mostly EMLs, thin-film lithium niobate (TFLN), indium phosphide, and silicon photonics.
Many companies are abandoning silicon photonics, but this author feels this is premature. There were demos at OFC of silicon photonics attaining near 400 gigabit-per-lane, and the technology is capable of it.
An important thing to remember is that the new OIO/SOC technology is silicon photonics and comes from a CMOS foundry. Putting non-CMOS materials such as thin-film lithium niobate or indium phosphide in such a platform could take years of expensive development and is thus unlikely.
In summary, OFC 2025 was very active and exciting. Significant technology improvements and innovations are needed.
The dust is far from settled, so we must continue wading into the storm and trying to understand it all.
Jörg-Peter Elbers, Senior Vice President, Advanced Technology, Standards and IPR, Adtran
OFC 2025 marked its largest attendance since 2003 with nearly 17,000 visitors, as it celebrated its 50th anniversary.
Discussions in 1975 centred around advances in fibre technology for telecommunications. This year’s hottest topic was undoubtedly optical interconnects for large-scale AI clusters.
Following an insightful plenary talk by Pradeep Sindhu from Microsoft on AI data centre architecture, sessions were packed in which co-packaged optics (CPO) and associated technologies were discussed. The excitement had been fueled by Nvidia’s earlier announcement of using co-packaged optics in its next generation of Ethernet and Infiniband switches.
The show floor featured 800 gigabit-per-second (Gbps), 1.6 terabit-per-second (Tbps), and the first 3.2Tbps interconnect demonstrations using different interface standards and technologies.
For access, 50G-PON was showcased in triple PON coexistence mode, while interest in next-generation very high-speed PON spurred the technical sessions.
Other standout topics included numerous papers on fibre sensing, stimulating discussions on optical satellite communications, and a post-deadline paper demonstrating unrepeated hollow-core fibre transmission over more than 200km.
OFC 2025 was fun too. When else do you get to reimagine communications after an alien attack, as in this year’s rump session?
No visit to San Francisco is complete without trying one of Waymo’s self-driving taxis. Having been proud of Dmitri Dolgov, Waymo’s CEO, for his plenary talk at OFC 2019, it was thrilling to see autonomous driving in action. I love technology!
Daryl Inniss, Omdia Consultant, Optical Components and Fibre Technologies
I worked on commercialising fibre technology for emerging applications at OFS – now Lightera – from 2016 to 2023. I spent the prior 15 years researching and analysing the optical components market.
Today, I see a market on the cusp of a transition due to the unabated bandwidth demand and the rise of computing architectures to support high-performance computing (HPC) and artificial intelligence (AI).
Even optical fibre, the fundamental optical communications building block, is under intense scrutiny to deliver performance suitable for the next 30 to 50 years. Options include hollow-core and multi-core fibre, two of the three fibre technologies that caught my attention at OFC 2025.
The third, polarisation-maintaining fibre arrays for co-package optics, is one part of the conference’s biggest story. OFC 2025 provided a status update on these technologies.
Hollow-core fibre
OFC’s first day hollow-core fibre workshop (S2A) illustrated its niche status and its potential to remain in this state until the fibre is standardised. The industry ecosystem was well represented at the session.
Not surprisingly, challenges highlighted and summarised by Russ Ellis, Microsoft’s Principal Cloud Network Engineer, included manufacturing, field installation, field splicing, cabling, and termination inside the data centre. These are all expected topics and well understood.
I was surprised to hear Microsoft report that the lack of an established ecosystem was a challenge, and I’ll explain why below.
Coming into OFC, the biggest market question was fibre manufacturing scalability, as most reported draws are 5km or less. Supplier YOFC put this concern to rest by showcasing a +20 km spool from a single fibre draw on the show floor. And Yingying Wang, CEO of Linfiber, reported that 50 to 100km preforms will be available this year.
In short, suppliers can scale hollow-core fibre production.
From a field performance perspective, Microsoft highlighted numerous deployments illustrating successful fibre manufacturing, cabling, splicing, termination, installation, and testing. The company also reported no field failures or outages for cables installed over five years ago.
However, to my knowledge, the hollow-core fibre ecosystem challenge is a consequence of a lack of standardisation and discussion about standardisation.
Each fibre vendor has a different fibre design and a different glass outer diameter. Microsoft’s lack-of-an-ecosystem comment mentioned above is therefore unsurprising. Only when the fibre is standardised can an ecosystem emerge, generating volumes and reducing costs,
Today, only vertically integrated players benefit from hollow-core fibre. Until the fibre is standardised, technology development and adoption will be stunted.
Multi-core fibre
I was pleasantly surprised to find multiple transceiver vendors showcasing modules with integrated fan-in/fan-out (FIFO). This is a good idea as it supports multi-core fibre adoption.
One vendor is targeting FR4 (TeraHop for 2x400G), while another is targeting DR8 (Hyper Photonix for 8x100G). There is a need to increase core density, and it is good to see these developments.
However, we are still very far from multi-core fibre commercialisation as numerous operational factors, for example, are impacted. The good news is that multi-core fibre standardisation is progressing.
Polarisation-maintaining fibre
According to Nick Psaila, Intel’s principal engineer and technology development manager, polarisation-maintaining fibre arrays remain expensive.
The comment was made at Optica’s February online Industry Meeting and verified in my follow-up conversation with Psaila.
Using an external laser source is the leading approach to deliver light for co-packaged optics, highlighting an opportunity for high-volume, low-cost polarisation-maintaining fibre arrays.
Co-packaged optics were undoubtedly the most significant topic of the show.
Coherent showcased a 3Tbps concept product of VCSELs to be used in co-packaged optics. Given that multimode fibre is used in the shortest optical connections in data centres and that VCSELs have very low power consumption, I’m surprised I’ve not heard more about their use for this application.
Testing of emerging photonic solutions for HPC and AI devices has been identified as a bottleneck. Quantifi Photonics has taken on this challenge. The company introduced an oscilloscope that provided quality results comparable to industry-leading ones and is designed for parallel measurements. It targets photonic devices being designed for co-packaged optics applications.
Multiple channels, each with wavelength-division multiplexing lasers, must be tested in addition to all the electrical channels. This is time-consuming, expensive process, particularly using existing equipment.
Polymer modulators continue to be interesting because they have high bandwidth and the potential to be inexpensive. However, reliability is their challenge. Another vendor, NLM Photonics, is targeting this application.
The many vendors offering optical circuit switches was a surprising development. I wonder if this opportunity is sufficiently large to justify the number of vendors. I’m told that numerous internet content providers are interested in the technology. Moreover, these switches may be adopted in telecom networks. This is a topic that needs continual attention, specifically regarding the requirements based on the application.
Lastly, Lightmatter provided a clear description of its technology. An important factor is the optical interposer that removes input-output connectivity from the chip’s edge, thereby overcoming bandwidth limitations.
I was surprised to learn that the laser is the company’s design, although Lightmatter has yet to reveal more.
OFC 2025: reflecting on the busiest optics show in years
The discussion covers the hot topics of the show and where the industry is headed next. Click here.
Adtran broadens its OLS and access module offerings
Adtran has unveiled two products before the OFC show in San Francisco taking place at the end of the month.
One is a 50 gigabit-per second (Gbps) SFP56 optical transceiver that uses 4-level pulse-amplitude modulation (PAM-4) for 5G front-haul and enhanced broadband applications.
The second product is the FSP 3000 IP OLS, a compact open line system (OLS) designed for point-to-point links between sites 120km apart.
The OLS has been developed to simplify the setting up of dense wavelength division multiplexing (DWDM) optical links.
Enhancing broadband
Adtran has been developing a range of transceiver products to address specific requirements in the access-aggregation marketplace.
These include the MicroMux Edge Bidi, a QSFP+ pluggable module that supports 4×10 gigabit signals over 40km for mobile backhaul and enterprise wireless applications.
Adtran also offers the AccessWave25, a 25-gigabit tunable wavelength transceiver in an SFP28 form factor with a reach of 40km.
The pluggable module is used to link remote physical layer devices (RPDs) in cable operators’ networks. Cable operators are upgrading their infrastructure from 10 gigabits to 25 gigabits to support DOCSIS 4.0.
“You can argue if DOCSIS 4.0 is here or coming at the year-end,” says Saeid Aramideh, vice president of business development, optical engines business unit, at Adtran. “But there is no argument about the need for 25-gigabit uplinks for the cable MSO market.”
Now Adtran is announcing the AccessWave50, a 50-gigabit SFP56 optical module for fronthaul, part of the radio access network (RAN) and for other developments driving traffic such as smart homes, Internet of Things, and Smart Cities.
Aramideh refers to these applications as driving ‘enhanced’ broadband networks, requiring the upgrading of 25 gigabit links to 50- and even 100-gigabit ones.
Front-haul networks
For mobile, telco operators and RAN equipment makers are working with optical component makers to drive innovation in pluggables for emerging architectures such as enhanced 5G and 6G, says Aramideh.
In mobile networks, the front-haul network carries radio signals using the CPRI (common public radio interface) or enhanced CPRI protocols between the remote radio heads and the baseband units.
For 5G front-haul, the modules used are mainly at 10 gigabits-per-second (Gbps) with some 25-gigabit modules deployed. Adtran’s AccessWave50 addresses the next speed hike.
Adtran has designed the AccessWave50 using proprietary signal-shaping and distance optimisation techniques along with 4-level pulse amplitude modulation (PAM-4) to achieve the 50Gbps line rate.
“PAM-4 is proving itself to be a cost-performance-optimised technology and give you spectral efficiency as you go to higher data rates,” says Aramideh. “Of course, it’s not coherent optics, but you don’t need coherent for all applications.”
AccessWave50 uses a tunable laser and has a 15km, not 40km reach, but that is sufficient, says Aramideh, since front-haul networks are latency-constrained. The SFP56 module consumes 2.5W only.
Compact networking
Adtran has also unveiled its latest open line system (OLS) for C-band coherent transceivers.
The company has been providing bespoke OLS systems for hyperscalers. ADVA, the company Adtran acquired in 2022, provided Microsoft with the OLS that, working with the original ColorZ modules from Marvell, enabled 100 gigabit PAM-4 transmissions over 80km links.
Adtran also provides an OLS for data centre interconnects using 400ZR coherent modules for reaches of 120km.
The latest FSP 3000 IP OLS platform is a compact one-rack (1RU) high box that supports eight wavelengths over 120km.
The platform also includes an OTDR (optical time domain reflectometer) for fibre diagnostics.
The OLS can be used with 400-gigabit, 800-gigabit, and ultimately 1.6 terabit coherent pluggable modules once available.
The OLS is also designed for telecom metro interconnect networks. “Telcos, in response to AI, are also looking for OLS technology tailored to coherent transceivers,” says Stephan Rettenberger, senior vice president of marketing and corporate communications at Adtran.
A chief design challenge has been to fit the OLS into a 1 RU form factor, requiring integration and packaging work. The OLS has also been designed to be set up and operated straightforwardly.
The platform is scalable: two racks stacked double the wavelength counts to 16.
The FSP 3000 IP OLS product is already in the hands of one telco customer, says Rettenberger.
Podcast: Is AI driving a new wave of photonic innovation?
AI is still in its infancy, but it’s already pushing the photonics and computing industries to rethink product roadmaps and drive new levels of innovation.
Adtran’s Gareth Spence talks with authors and analysts Daryl Inniss and the editor of Gazettabyte about the fast pace of AI development and the changes needed to unlock its full potential. They also discuss the upcoming sequel to their book on silicon photonics and its focus on AI.
To listen to the podcast, click here.
ECOC 2024 industry reflections - Final Part
In the final part, industry figures share their thoughts after attending the recent 50th-anniversary ECOC show in Frankfurt. Contributions are from Adtran’s Jörg-Peter Elbers, Lightwave Logic’s Michael Lebby, and Heavy Reading’s Sterling Perrin.
ECOC exhibition floor
Jörg-Peter Elbers, senior vice presendent, advanced technology, standards and IPR, Adtran, and a General Chair at this year’s ECOC.
ECOC celebrated its 50th anniversary this year. It was great to see scientists, engineers, and industry leaders from all around the globe at a vibrant gathering in Frankfurt.
ECOC dates to September 1975 when the inaugural event – dubbed the “European Conference on Optical Fiber Technology” – was held in London. In the early days, the focus was on megabit-per-second transmission for telephony applications. Now, we are advancing to petabit-per-second speeds to meet AI and cloud services demands.
This year’s ECOC explored various cutting-edge topics, including 1.6 and 3.2 terabit-per-second (Tb/s) transceivers, multi-band and spatial division multiplexing (SDM) transmission, and innovations in access and home networks. Other discussions centred on the merits of linear drive versus regenerated optics, pluggable modules versus co-packaged engines, and the latest IP-over-DWDM architectures and technologies for the coherent edge.
The 50 years of ECOC symposium celebrated the amazing progress of optical communications in the past and painted a promising picture for the future.
David Payne, one of the luminary speakers, stated that hollow-core fibre would enable a new generation of WDM transmission systems (“amplifier-less”) with simpler terminals and higher fibre capacity. In a post-deadline paper, Linfiber reported a hollow-core fibre deployment with a fibre loss lower than solid-core fibre and progress on manufacturing and deployment issues, critical for mass-market adoption.
In the ECOC plenary session, Arista’s Andy Bechtolsheim discussed the race to build AI clusters for generative AI learning and inference. He emphasized that the next generation of hyperscale AI data centres could contain a million AI nodes requiring more than 3GW of electrical power—comparable to the output of a vast nuclear plant. These data centres present opportunities for millions of cost-efficient, low-power terabit-per-second optical interconnects.
The theme of optics for AI was complemented by exploring AI for optics, with multiple contributions examining how generative AI and agent-based models could streamline network operations. The accuracy, predictability, and the explainability of results remain active research topics.
Another highlight was the optical satellite symposium, which discussed using 100 gigabit-per-second (Gbps) coherent optics for satellite communications. While inter-satellite links in commercial low-earth orbit (LEO) constellations use coherent transceiver technology, the use of optical ground links is still in its infancy. Panelists emphasised the challenges of maintaining cloud-free line-of-sight conditions and compensating for atmospheric turbulence to ensure continuous communication. They agreed that combining adaptive optics with time diversity (e.g., by interleaving) offers the best solution for turbulence mitigation, though it adds latency.
Other discussions covered fibre sensing for infrastructure and environmental monitoring and the commercial potential of quantum technologies, sparking much interest and heated debate in this year‘s Rump Session.
As ECOC 2024 concluded, it was clear that the conference not only celebrated five decades of advancement in optical communications but also set the stage for future innovations and challenges.
Dr. Michael Lebby, CEO, Lightwave Logic
As the Chair of the Market Focus at ECOC’s Industry Exhibit, I can say that this year, we had probably the best sessions in ECOC’s 50-year history. For three days, each seat was taken at the Market Focus, which featured wall-to-wall programming on commercial trends, technologies, and roadmaps in optical communications.
Presentations at the market focus sessions supported the big-show exhibition themes. Many talks focused on modules and subsystems. Lightwave Logic showed polymer silicon slot modulators with reliability data operating at 200Gbps with less than 1V drive, with initial results of polymer-plasmonic modulators operating with open 400Gbps eyes. While 400Gbps lanes are still on the roadmap, there were many discussions on what technologies could reach this level of performance, especially modulators. Polymer-plasmonic-based modulators seem to be the leader, with optical bandwidths exceeding 500GHz.
While incumbent technologies are hard to displace, the emerging area of co-packaged pluggables is gaining interest among suppliers, especially for the terabit-per-second data rates sought. While progress was impressive, the reach of silicon photonics modulators for 200Gbps and beyond was a show floor concern.
NewPhotonics discussed how to double data rates using its integrated optical equaliser, while others, such as Pilot Photonics, conveyed the exciting progress with comb laser arrays. Several speakers discussed the metrics of standards that support the AI/ machine learning trends for data centre operators and how optics can support the drive to higher data rates and lower power consumption.
Areas of power consumption driven in part by digital signal processor (DSP) evolution were discussed. The interesting perspective is that if coherent optics are to be developed to serve the edge of the network, then using electronics to help the optics may not be enough; the optics need to perform better so that the electronics can be scaled down to reduce power consumption. It is a trade-off at the heart of many approaches to bring coherent optics to compete with direct-detect solutions for pluggable transceivers.
The indication is that direct detection in data centre optics is not waning as quickly as the community once thought and looks to be a mainstay for pluggable transceiver solutions from 800Gbps, 1.6Tbps, 3.2Tbps, and even 6.4Tbps.
A fireside chat explored the opportunities for copper at super short interconnects where the direct-attach copper (DAC) cables dominate. This 1m to 3m range has been evolving to active electrical copper (AEC) interconnects using smart electronics in recent years. Those of us who are solidly in the optics camp, while acknowledging that copper has owned this segment forever, are still hoping that platforms such as silicon photonics could sneak in and take share in the next five years. However, displacing an incumbent technology such as copper will not be easy, especially when metrics such as economies of scale, cost, and reliability come into play.
Several talks looked at next-generation implementations, such as quantum-dot lasers and photonic wire bonding, and driving VCSELs to ever-increasing speeds. Discussions took place that wondered if VCSELs have reached their limit in bandwidth and speed and if electronics could help them push performance further. A common theme evident was the innovative ideas and concepts to address 224Gbps per lane with optical technologies. While it has been generally accepted that this metric is emerging, several companies are still deciding how to address this speed and 400Gbps per lane.
One big takeaway is that if you have a new and innovative platform to enable things like 3.2Tbps transceivers that is disruptive, think very carefully about whether that disruptive technology needs the infrastructure to be disruptive, too.
Sterling Perrin, Senior Principal Analyst, Heavy Reading
Although I’ve attended nearly every OFC show over the past 25 years, this was my first ECOC. Most of my meetings were centred around an IP-over-DWDM project I’ve worked on for several months, including video interviews conducted at the show with the partnering companies: the OIF, Ciena, Juniper, and Infinera. These are all posted on Light Reading.
Building on its work at OFC 2024, the OIF’s pluggables demo at ECOC spotlighted four applications:
- 400ZR and 800ZR,
- Open ZR+ at 400GbE,
- OpenROADM at 400GbE, and
- 100ZR
The expanding scope of coherent pluggable is impressive, and the interop work includes optics that the OIF is not directly defining—such as Open ZR+, OpenROADM, and 100ZR. ECOC 2024 marked OIF’s first interoperability demonstration of 100ZR modules, an application driven by telecom operators as opposed to hyperscalers.
Another key aspect of the OIF’s IP-over-DWDM work demonstrated at ECOC is the common management interface specification (CMIS) for plug-to-host interoperability between routers and pluggable optics. Plug-to-host interop is essential for wider IP-over-DWDM adoption among telecom operators, so the work is timely.
Related to pluggables management in IP-over-DWDM networks, I attended the Open XR Forum’s symposium on the show floor. The organisation is promoting a dual management approach to pluggables that includes host independent management to support pluggables features that aren’t yet supported in the routers or in CMIS.
During a Q&A, Telefonica’s Oscar Gonzales de Dios acknowledged that host-independent management is controversial (including within Telefonica) but said it is the only way to add point-to-multipoint functions on pluggables for now.
Quantum-safe encryption is another area of research interest, particularly quantum key distribution (QKD), and ECOC 2024 was a great place to get up to date. I attended the rump session debate on quantum technologies, expertly hosted by Peter Winzer (Nubis), Rupert Ursin (QTlabs), and David Neilson (Nokia Bell Labs). It was standing-room-only, and I anticipated strong pro-QKD sentiment. I was wrong! The dominant view was that QKD is impractical, technically limited, too expensive, and needs more real customer demand. Several people argued that post quantum cryptography (PQC) algorithms are sufficient to meet the market needs, without the complexity and costs that QKD brings.
For analysts, conferences like ECOC are the most efficient means of quickly learning what’s hot in the industry. Conferences are equally great places to know what is not hot. I didn’t hear the words “5G,” “xHaul,” “fronthaul,” “6G,” or even “mobility” uttered once during the four days I was in Frankfurt.
ECOC celebrates its 50th anniversary
- The European Conference on Optical Communications (ECOC) is celebrating its 50th anniversary.
- The conference and exhibition will take place in Frankfurt, Germany, from September 22-26.
- Key themes at the show include satellite optical communication, artificial intelligence, networking for AI within the data centre, photonic integration, quantum and Green ICT.
ECOC will celebrate its 50th anniversary this month.
The event will include a special session highlighting the progress made in photonics over the last half century and will feature luminary speakers.
There will also be a celebratory event with food stalls from different countries.
“There will be an opportunity to mingle, and we also plan an exhibition to look back at what has been achieved combined with what directions we need to take for the future,” says Jörg-Peter Elbers, an ECOC General Chair this year.
“Photonics is now very important for digitalising different protocols,” adds Ronald Freund, another of the General Chairs. “It is not just telecommunications but also photonic networks for the industrial production of almost anything you can imagine.”
Conference themes
The use of photonics for communications has become so diverse that no one theme captures the show. Rather, the General Chairs highlight several themes at this year’s event.
“There are hot topics that we have tried to cover, while also recognising that we have a broad audience,” says Elbers. The audience ranges from communications service providers to component makers and chip foundry operators.
“One topic is satellite network integration in the optical domain,” says Professor Carmen Mas Machuca, the third ECOC General Chair. “Satellite networks using all this optical technology is one of the new topics.”
There is ongoing research work to combine terrestrial and space networks to address capacity gaps and bolster networking resiliency. Satellite can take over for any failures in the terrestrial core network. Satellite networks also offer latency benefits which can benefit niche applications like high-frequency trading.
Combining satellite and terrestrial networks represents a tremendous opportunity but has it challenges, says Elbers. An optical satellite symposium will be hosted at ECOC.
Another topic is sensing that will be addressed in multiple sessions. Examples include using optical fibre network for sensing, to wearables such as brain-computer interfaces (see Conference keynotes, next section).
Freund highlights other networking symposia addressing the data centre, and Green ICT. “How photonics can contribute to reach net zero targets,” says Freund.
“We wanted to highlight the breadth of the topic, how many different problems we can solve with optical technologies,” says Elbers.”
Conference keynotes
ECOC will feature four keynote speakers.
This year, the topics are AI interconnect requirements in the data centre, optical networking, past and future, for telecom, silicon photonics, and using photonics for computation.
- Andy Bechtolsheim, co-founder and Chief Architect at Arista Networks, will address whether interconnects can keep up with the demands of AI. Bechtolsheim will outline ways to improve the power, cost, and reliability of optics for interconnects needed for AI, the boundaries between copper and optics, and packaging innovations.
- Thomas van Briel is the Senior Vice President of Architecture and Strategy at the communications service provider Deutsche Telekom. His will address the evolution of IP and optical networks and the technologies that have driven and will drive optical networking.
- Roel Baets is an Emeritus Professor at Ghent University and former Group Leader at imec. His talk is on ‘Silicon Photonics 4.0’. If the title puzzles you, then it is well chosen, quips Professor Baets. “What I mean is that it will be important for silicon photonics to make use of smart and agile manufacturing, a notion associated with Industry 4.0,” says Baets. “Silicon photonics can be expected to be an enabling technology for Industry 4.0 since it can enable more performant AI, sensors for IoT, and more.”
- The final speaker is Joyce Poon, Head of Photonics Architecture at Lightmatter. She will address future computing examples involving integrated photonics. Lightmatter believes the most significant opportunities and challenges in computing lie at the extremes in size and scale: large data centres and personal devices. Poon will detail how advanced integrated photonics can transform computing, from making large-scale AI systems more efficient to enabling wearables and human brain-computer interfaces.
Rump Session
This year’s Rump Session is titled: Quantum Technologies: Research hype or on track to commercial success?
The Rump Session will look at the funding Quantum players are attracting and address what financial return, if any, has been achieved. The topics to be tackled include quantum secure communications and quantum computing.
“Quantum companies are mushrooming everywhere, with Europe maybe an extreme case,” says Elbers. “It is interesting to explore what is behind this and what happens if the funding dries up?”
The session will address what is real and ready for near-term commercial deployment and what remains longer term.
Individual interests
Each Chair has their own ECOC interests regarding the latest research.
“My interest is to see how the energy bottleneck in the data centre will be solved concerning the demands of the AI processors,” says Freund. “One interesting approach is to move forward with integration, for instance, co-packaged optics and whether there are other possibilities.”
Professor Mas Machuca is interested in network security. “How can we use all these entanglement properties [to detect eavesdropping] so they can be applied in real networks?” she says. “For now, they are far from deployment, and it will be interesting to see how far it can go.”
The challenges with entanglement are the limited distances and durations achieved, measured in milliseconds, says Professor Mas Machuca.
Elbers’s hot topic is photonic integration: “The progress here has been tremendous.” What interests him is how to bring the functional blocks closer and building new functions using chiplets, for example.
Another of his interests at the show is how generative AI can be ued to enable customers to operate their networks more efficiently.
Industry issues
What are the Chairs’ concerns and observations regarding the photonics industry?
For Europe, there is a gap between research and forming of companies, says Freund. There is progress but more momentum is needed for start-ups to transfer innovation from research into applications so that smaller companies can provide solutions for larger ones.
“There’s a lot of money around, but there also has to be the people – entrepreneurs – to do that,” says Freund.
Professor Mas Machuca highlights sovereignty issues such that telecom operators in Europe have the suppliers to guarantee working networks. “How to design your network so that if one manufacturer is banned from your country, you still have an operating network,” says Professor Mas Machuca.
It requires standardisation efforts that the equipment makers must follow to ensure interoperability. “This is always a challenge,” she says.
Elbers overall is positive but does highlight challenges. The fundamental drivers remain: traffic growth is continuing while there are government investments to promote broadband in rural areas.
But there are also geopolitical issues that are forcing the telecom operators to chose carefully their suppliers. These geopolitical issues are also forcing equipment vendors to focus on particular markets.
There is also equipment-maker consolidation taking place, the recent Nokia-Infinera announcement being an example.
“That certainly brings challenges for some people, but I think it also brings opportunities for others,” says Elbers.
Industry issues
Carmen Mas Machuca is the Professor of Communication Networks at the Department of Electrical Engineering and Information Technology at the University of the Bundeswehr, Munich. Her interests include network planning, resource allocation, and resiliency of telecom networks, not just core but also access networks.
Jörg-Peter Elbers is Senior VP, Advanced Technology, Standards and IPR, at Adtran Networks. His responsibilities cover optical packet networks, optical access, and residential gateways.
As passive optical network speeds rise to 50 gigabit-per-second and beyond, there is a blurring between access, aggregation, and metro regional networks, says Elbers. There is also the growing importance of photonic integration as part of system design and this is also impacting his work interests.
Ronald Freund heads the telecommunications systems group at the Fraunhofer Heinrich Hertz Institute (HHI), Germany. The HHI is the largest applied research organization in Europe.
Freund’s group research interests span the full spectrum of networks – from in-house, access, and metro to wide area networks. A key focus of research is fibre-based communications to advance reach, capacity, and data rates, as well as network security and power consumption issues. The group has also started to address optical satellite and optical free-space communications.
OFC 2024 industry reflections: Part 4
Gazettabyte is asking industry figures for their thoughts after attending the recent OFC show in San Diego. This penultimate part includes the thoughts of Cisco’s Ron Horan, Coherent’s Dr. Sanjai Parthasarathi, and Adtran’s Jörg-Peter Elbers.
Ron Horan, Vice President Product Management, Client Optics Group, Cisco
Several years ago, no one could have predicted how extensive the network infrastructure required to support artificial intelligence (AI) and machine learning (ML) back-end networks in data centres would be. This year’s OFC answered that question. In a word, immense.
By 2025, the optics total addressable market for AI/ML back-end networks is expected to equal the already substantial front-end network optics market. By 2027, the back-end network optics total addressable market is projected to significantly exceed that of the front-end network. Additionally, the adoption of higher speeds and interface densities in the AI/ML back-end network will likely surpass that of the front-end.
Last year, linear pluggable optics (LPO) advocates heralded the power and cost savings associated with removing the digital signal processor (DSP) from an optics module and driving it directly from the host ASIC. Cisco and others have shown, using data and demos, that the overall power and cost savings are significant. However, in the last year, enthusiasm for this disruptive technology has been checked as concerns about link robustness and accountability have surfaced.
Enter linear receive optics (LRO), where the transmit path gets retimed while the high-power module receiver path moves to a linear receiver, which drives directly to the host ASIC. While not as power or cost friendly as linear pluggable optics, it does reduce power and some cost from the module compared to a fully retimed module while providing some diagnostic support for the link.
Only time and significant interoperability testing will determine whether linear pluggable optics or linear receive links will be robust enough to make them deployable at scale. Additionally, today’s linear pluggable and linear receive solutions have only been shown at 100 gigabits per lane. It is unclear whether 200 gigabits per lane for both approaches can work. Many think not. If not, then 100 gigabit per lane linear pluggable and linear receive optics may be a one-generation technology that is never optimal. The LPO-MSA, an industry effort that included many of the industry’s key companies, was announced before OFC to specify and resolve interoperability and link accountability concerns.
The overall concern about reducing power in the data centre was a strong theme at the show. The linear pluggable optics/ linear receive optics theme was born from this concern. As optics, switches, routers, and GPU servers become faster and denser, data centres cannot support the insatiable need for more power.
However, end users and equipment manufacturers seek alternative ways to lower power, such as liquid cooling and immersion. Liquid cooling uses liquid-filled pipes to remove the heat, which can help cool the optics. Liquid immersion further amplifies the cooling approach by immersing the optics, along with the host switch or GPU server, directly into an inert cooling fluid or placing them just above the fluid in the vapour layer. The ultimate result is to operate the optics at a lower case temperature and save power. It seems each customer is approaching this problem differently.
Last year’s OFC produced the first optics with 200 gigabit per optical lane technology. These solutions assumed a gearbox to a host interface that used 100-gigabit electrical channels. While some early adopters will use systems and optics with this configuration, a more optimal solution using 200 gigabits per lane electrical channels between the host and optics will likely be where we see 200 gigabits per lane optics hit their stride. This year’s show revealed a broader set of optics at 200 gigabit per lane rates. The technology maturity was markedly improved from last year’s early feasibility demos.
This is an exciting time in the optics industry. I look forward to learning what technologies will be introduced at OFC 2025.
Dr. Sanjai Parthasarathi, Chief Marketing Officer, Coherent
The progress in making 200-gigabit VCSELs ready for 200-gigabit PAM-4 optical transmission was a pleasant surprise of the event.
We at Coherent presented a paper on our lithographic aperture VCSEL, while Broadcom’s presentation outlined the technical feasibility of 200-gigabit PAM4 links. While both mentioned that more work is needed, the historic success of VCSEL-based links in short-reach interconnects suggests that the arrival of 200G-capable VCSELs will significantly impact the datacom market.
The feasibility of linear pluggable optics has likely delayed the market acceptance of co-packaged optics. There seems to be widespread consensus that LPO can reduce cost and power while retaining all the advantages of pluggable transceivers – a vibrant ecosystem, deployment flexibility, and a clear distinction of link accountability.
Jörg-Peter Elbers, senior vice president, advanced technology, standards and IPR, Adtran.
At this year’s OFC, discussions were much hotter than the weather. Who would have anticipated rain, winds and chilly temperatures in an always-sunny San Diego?
AI infrastructure created the most buzz at OFC. Accelerated compute clusters for generative AI are expected to drive massive demands for high-speed interconnects inside cloud-scale data centres. Consequently, 800-gigabit, 1.6-terabit, and future 3.2-terabit pluggable optical transceivers for front-end and back-end data centre fabrics stirred a lot of interest. Progress on co-packaged optics was also exciting, yet the technology will only go into deployments where and when pluggable transceivers hit unsurmountable challenges.
Silicon Photonics, indium phosphide, thin-film lithium niobate and VCSEL-based optics compete for design slots in a very competitive intra-data centre market, leading to new partnerships across the pluggable transceiver value chain. Linear receive optics and linear transmit & receive pluggable optics offer opportunities to reduce or eliminate DSP functions where electrical signal integrity permits.
While green ICT (information and communications technology) received a lot of attention at the conference, comments at the OFC Rump Session on this topic were somewhat disenchanting: time-to-market and total-cost-of-ownership drive deployment decisions at hyperscale data centres; lower energy consumption of optics is welcome but not a sufficient driver for architectural change.
On the inter-data centre side, a range of companies announced or demonstrated 800G-ZR/ZR+ transceivers at the show. More surprising was the number of transceiver vendors – including those not traditionally active in this market domain – who have added 400G-ZR QSFP-DD transceivers to their product portfolio. This indicates that the prices of these transceivers may decline faster than anticipated.
As for the next generation, industry consensus is building up behind a single-wavelength 1.6T ZR/ZR+ ecosystem using a symbol rate of some 240 gigabaud. There was a period in which indium phosphide and silicon photonics seemed to have taken over, and LiNbO3 appeared old-fashioned. With the move to higher symbol rates, LiNbO3 – in the form of thin-film Lithium Niobate – is celebrating a comeback: “Lithium Niobate is dead – long live Lithium Niobate!”
The OIF’s largest ever interop demo impressively showed how 400G-ZR+ modules can seamlessly interoperate over long-haul distances using an open-line system optimized for best performance and user-friendly operation. Monitoring and controlling such pluggable modules in IPoWDM scenarios can create operational and organizational challenges and is the subject of ongoing debates in IETF, TIP and OIF. A lean demarcation unit device can be a pragmatic solution to overcome these challenges in the near term. In the access/aggregation domain, the interest in energy-efficient 100G-ZR solutions keeps growing.
As the related OFC workshop showed, growing is also the support for a coherent single-carrier PON solution as the next step in the PON roadmap after 50Gbps very high-speed PON (VHSP).
Overall, there was excitement and momentum at OFC, with the conference and show floor returning to pre-Covid levels.
This is a good basis for the 50th anniversary edition of ECOC, taking place in Frankfurt, Germany, on September 22-26, 2024.
AI and optics: An OFC conversation
An OFC conversation with Adtran's Gareth Spence and consultant Daryl Inniss about the AI opportunity for photonics, click here.
ECOC 2023 industry reflections - Final Part
Gazettabyte has been asking industry figures to reflect on the recent ECOC show in Glasgow. The final instalment emphasises coherent technology with contributions from Adtran, Cignal AI, Infinera, Ciena, and Acacia.
Jörg-Peter Elbers, head of advanced technology at Adtran
The ECOC 2023 conference and show was a great event. The exhibition floor was busy and offered ample networking opportunities. In turn, the conference and the Market Focus sessions provided information on the latest technologies, products, and developments.
One hot topic was coherent 800ZR modems. Several vendors demonstrated coherent 800ZR modules and related components. Importantly, these modules also boast new and improved 400 gigabit-per-second (Gbps) modes. The 120 gigabaud (GBd) symbol rate enables 400-gigabit dual-polarisation quadrature phase shift keying (DP-QPSK) transmission over demanding links and long-haul routes. In turn, the advent of 5nm CMOS digital signal processor (DSP) technology enables lower power DP-16QAM than 400ZR modules.
There is broad agreement that the next step in coherent transmission is a 240GBd symbol rate, paving the way to single-wavelength 1.6 terabit-per-second (Tbps) optical transport.
Meanwhile, the use of coherent optical technology closer to the network edge continues. Several players announced plans to follow Adtran and Coherent and jump on the low-power 100 gigabit-per-second ZR (100ZR) ‘coherent lite’ bandwagon. Whether passive optical networking (PON) systems will adopt coherent technology after 50G-PON sparked lively debate but no definitive conclusions.
The OIF 400ZR+ demonstration showed interoperability between a dozen optical module vendors over metro-regional distances. It also highlighted the crucial role of an intelligent optical line system such as Adtran’s FSP3000 OLS in automating operation and optimising transmission performance.
The post-deadline papers detailed fibre capacity records by combining multiple spectral bands and multiple fibre cores. The line-system discussions on the show floor focused on the practical implications of supporting C-, L-, extended, and combined band solutions for customers and markets.
From workshops to the regular sessions, the application of artificial intelligence (AI) was another prominent theme, with network automation a focus area. Examples show not only how discriminative AI can detect anomalies or analyse failures but also how generative AI can improve the interpretation of textual information and simplify human-machine and intent interfaces. For network engineers, ‘Copilot’-like AI assistance is close.
After ECOC is also before ECOC, so please mark in your calendars September 22-26, 2024. ECOC will celebrate its 50th anniversary next year and will take place in Frankfurt, Germany. As one of the General Chairs of the ECOC 2024 event, and on behalf of the entire organising committee, I look forward to welcoming you!
Andrew Schmitt, founder and directing analyst, Cignal AI
ECOC is a great show, it’s like OFC (the annual optical communications and networking event held in the US) but refined to only the critical elements. Here are my key takeaways.
The most impressive demonstration was 800ZR test boards and modules from Marvell and its partners Coherent and Lumentum. Within eight weeks of the first silicon, Marvell has demos up and running in-house and at its partners. The company has at least a 6-month lead in the 800ZR market, making intelligent tradeoffs to achieve this.
Lumentum showed an 8-QAM mode of operation that allows 800 gigabit transmission within a 100GHz channel spacing, which should be interesting. After the massive success of 400ZR, it’s natural to extrapolate the same success for 800ZR, but the use cases for this technology are substantially different. We also heard updates and broader support for 100ZR.
Linear drive pluggable optics (LPO) was a hot topic, although it was our impression that, while optimism ruled public discussion, scepticism was widely expressed in private. There was more agreement than disagreement with our recent report (see the Active Insight: The Linear Drive Market Opportunity). No one is more confident about LPO than the companies who view this as another opportunity to bid for business at hyperscale operators they don’t currently have.
The 200 gigabit per lane silicon/ physical media device (PMD)/ optics development continues, and it is on track to enable 1.6-terabit optics by 2024. Marvell had a more advanced and mature demo of what they showed behind closed doors at OFC. The advancements here are the real threat to adopting LPO, and people need to realise that LPO is competing with the power specs of 200 gigabits per lane, not 100 gigabits per lane solutions.
Also impressive was the comprehensive engineering effort by Eoptolink to show products that covered 100 gigabit and 200 gigabit per lane solutions, both retimed and linear. The company’s actions show that if you have the engineering resources and capital, rather than pick the winning technology, do everything and let the market decide. Also impressive is the CEO, who understood the demos and the seasoned application engineers. Kudos to keeping engaged with the products!
System vendors had a more significant presence at the show, particularly Ciena and Infinera. It’s unsurprising to see more system vendors since they are increasing investments in pluggables, particularly coherent pluggables.
We had many discussions about our forecasts for IPoDWDM deployment growth. This disruption is something that component vendors are excited about, and hardware OEMs view it as an opportunity to adjust how they deliver value to operators (see the Active Insight: Assessing the Impact of IP-over DWDM).
Lastly, the OIF coordinated 400ZR+ and OpenROADM interoperability testing despite the organisation not being directly involved in those industry agreements. The OIF is a fantastic organisation that gets valuable things done that its members need.
Paul Momtahan, director, solutions marketing, Infinera
ECOC 2023 provided an excellent opportunity to catch the latest trends regarding transponder innovation, coherent pluggables and optical line systems. A bonus was getting to the show without needing a passport.
Transponder innovation topics included coherent digital signal processor (DSP) evolution, novel modulators, and the maximum possible baud rate. DSP sessions included the possibility of offloading DSP functions into the photonic domain to reduce power consumption and latency.
There were also multiple presentations on constellation shaping, including enhanced nonlinear performance, reduced power consumption for probabilistic constellation shaping, and potential uses for geometric shaping.
Novel modulators with very high baud rates, including thin-film lithium niobate, barium titanate, plasmonic, and silicon-organic hybrid, were covered. The need for such modulators is the limited bandwidth potential of silicon photonics modulators, though each face challenges such as integration with silicon photonics and manufacturability.
From the baud rate session, the consensus was that 400GBd symbol rates are probable, up to 500GBd might be possible, but higher rates are unlikely. The critical challenges are the radio frequency (RF) interconnects and the digital-to-analogue and analogue-to-digital converters. However, several presenters wondered whether a multi-wavelength transponder might be more sensible for symbol rates above 200 to 250GBd.
Coherent pluggables were another topic, especially at 800 gigabit. However, one controversial topic was the longevity of coherent pluggables in routers (IPoDWDM). Several presenters argued the current period would pass once router port speeds and coherent port speeds no longer align.
As the coherent optical engines approach the Shannon limit, innovation is shifting towards optical line systems and fibres as alternative way to scale capacity.
Several presentations covered ROADM evolution to 64 degrees and even 128 degrees. A contrasting view is that ROADMs’ days are numbered to be replaced by fibre switches and full spectrum transponders, at least in core networks.
Additional options for scaling capacity included increasing the spectrum of existing bands with super-C and super-L. Lighting different bands, such as the S-band (in addition to C+L bands), is seen as the best candidate, with commercial solutions three to five years away.
Overall, it was a great event, and I look forward to seeing how things evolve by the time of next year’s ECOC show in Frankfurt. (For more, click here)
Helen Xenos, senior director, portfolio marketing, Ciena
This was my third year attending ECOC, and the show never disappoints. I always leave this event excited and energised about what we’ve accomplished as an industry.
Every year seems to bring new applications and considerations for coherent optical technology. This year, ECOC showcased the ever-growing multi-vendor ecosystem for 400-gigabit coherent pluggable transceivers, considerations in the evolution to 800-gigabit pluggables, evolution to coherent PON, quantum-secure coherent networking, and the evolution to 200 gigabaud and beyond. When will coherent technology make it into the data centre? A question still open for debate.
Ciena’s optical engineer wizards were on hand to share specifics about our recently announced 3nm CMOS-based WaveLogic 6 technology, which includes the industry’s first performance-optimised 1.6 teraburs-per-second (Tbps) optics as well as 800-gigabit pluggables.
It was exciting for me to introduce customers, suppliers and research graduates to their first view of 3nm chip performance results and show how these enable the next generation of products. And, of course, Ciena was thrilled that WaveLogic 6 was awarded the Most Innovative Coherent Module Product at the event.
Tom Williams, director of technical marketing at Acacia
From my perspective, while there weren’t as many major product announcements as OFC, several trends and technologies continued to progress, including OIF interoperability, 800ZR/ZR+, linear pluggable optics (LPO) and terabit optics.
The OIF interop demonstration was once again a highlight of the show. The booth was at the entrance to the exhibition and seemed to be packed with people each time I passed by.
OIF has expanded the scope of these demonstrations with each show, and this year was the largest ever. In addition to having the participation of 12 module vendors (with 34 modules), the focus was on the ZR+ operation. What was successfully demonstrated was a single-span 400ZR network and a multi-span network.
As co-chair of the OpenZR+ MSA, I was excited by the great collaboration with OIF. These efforts help to drive the industry forward. Karl Gass is not only the most creatively dressed person at every trade show; he is exceptional at coordinating these activities.
It is clear that linear drive pluggable optics (LPO) works in some situations, but views differ about how widespread its adoption will be and how standardisation should be addressed. I lived through the analogue coherent optics (ACO) experience. ACO was essentially a linear interface for a coherent module where the digital processing happened outside the module. For ACO, it was a DSP on the host board and for LPO it is the switch ASIC. The parameters that need to be specified are similar. There is a precedent for this kind of effort. Hopefully, lessons learned there will be helpful for those driving LPO. I am interested to see how this discussion progresses in the industry as some of the challenges are discussed, such as its current limited interoperability and support for 200 gigabits per lane.
There have been announcements from several companies about performance-optimised coherent optics in what we call Class 3 (symbol rates around 140 gigabaud), which support up to 1.2 terabits on a wavelength. Our CIM 8 module has been used in multiple field trials, demonstrating the performance benefits of these solutions.
Our CIM 8 (Coherent Interconnect Module 8) achieves this performance in a pluggable form factor. The CIM 8 uses the same 3D siliconisation technology we introduced for our 400-gigabit pluggables and enables operators to scale their network capacity in a cost- and power-efficient way.