One of the key roles that CableLabs plays for our member operators and the vendor community is tracking trends in key areas of the broadband industry. Because the networks operated by our members are predominantly fiber, we are always keeping a close eye on the optical industry — but this year is proving to be an especially exciting one across a range of optical topics.

In this blog post, we explore some of the key topics driving today’s optical industry, focusing on artificial intelligence and machine learning (AI/ML). Let’s dig in.

Short-Reach Optical Transceiver Market

Over the past few years, datacom has surpassed legacy telecom in driving the optical communication industry. However, the rapid development of AI computing is taking center stage and taking over the short-reach optical transceiver market, which has ignited innovation across the industry.

AI/ML is driving the need for increased computing power at an astonishing rate, with company after company announcing newer and more powerful chips in rapid succession. These chips are deployed en masse in data centers, creating rack after rack of computing power. But to harness their full power, they have to be used together. And that requires interconnects, including:

• Graphics processing unit (GPU)-to-GPU
• GPU-to-central processing unit (CPU)/high bandwidth memory (HBM)
• GPU/CPU to frontend and backend switches, and network interface cards (NICs)

Currently, copper cables are employed for all intra-rack 400G and 800G interconnects because of their power, cost and reliability advantages. The question is, when the data rate scales up to 1.6T and 3.2T, and the per-lane rate increases to 200G and 400G, is copper still the right solution? And what about clusters as a chip — multiple racks in a cluster, with a multitude of chips acting together as one — which requires immense amounts of data throughput and very low latency communication between racks?

Based on the work taking place right now, it seems optical technology will be the technology of the future to support these needs.

What Optical Technologies Might Support AI/ML?

A range of technologies are the subject of extensive investigation for potential use in supporting both intra- and inter-rack communication for 200G and 400G per lane, including:

• Vertical-cavity surface-emitting lasers (VCSEL) with multimode fiber
• Silicon photonics
• Electro-absorption-modulated laser (EML) with single-mode fiber

Additionally, in the drive to increase density and flexibility, reduce power consumption, lower cost and reduce latency, members of the industry are looking at different optical transceiver packaging options, including:

• Full-DSP pluggable transceivers
• Half re-timed pluggable transceivers
• Linear-drive pluggable transceivers
• Co-packaged optics solutions

Further, optical circuit switching (OCS) based on micro-electromechanical systems (MEMS) is being implemented for the first time inside data centers by Google, seeking to enable topology reconfiguration, flexible upgrades, network resiliency and traffic grooming.

Liquid cooling is being introduced to keep communication systems running smoother and more efficiently than traditional air-cooled approaches: While liquid cooling is no longer that unusual in computer platforms, this is something very new in optical equipment.

What Does This Mean for the Broadband Industry?

This work will impact the industry in a number of different ways.

Broadband operators are increasingly operating data centers, leveraging their networks and distributed footprint to bring scalable computing closer to customers. AI/ML computing will inevitably be a part of that, and these technological advances will support the operators' ability to deploy powerful, scalable, cost-effective solutions.

Telecom can even take advantage of these new innovations in their own networks, leveraging the immense scale of datacom to keep the costs of these new solutions as low as possible, resulting in a win-win scenario.

Of course, this is just the tip of the iceberg for what’s happening in the optical industry!

These trends are already dominating agendas at industry events, including this spring’s Optical Fiber Conference (OFC) in San Diego — the world’s largest conference and exhibition for optical communications. A tangible energy and excitement flowed through the OFC sessions and the exhibition floor as industry leaders discussed technology innovations and advancements that will power the future.

ECOC 2024

Later this month, I’m an invited speaker at Europe’s counterpart to OFC: the European Conference on Optical Communication (ECOC) 2024 in Frankfurt, Germany. If you’ll be there, join me for three sessions in which I’ll be presenting:

Sunday, Sept. 22

• “Beyond 50G-PON — Can We Still Use IMDD?”

Monday, Sept. 23

• “Advances in the Latest Coherent PON Technology and Industry Specification Development”

Tuesday, Sept. 24

• “Adaptable Modulation and Baud Rates in Coherent TFDM PONs: Towards Versatile High-Speed Access Networks”

SCTE TechExpo24

If you’re attending SCTE TechExpo in Atlanta, join my CableLabs colleagues for several optical- and PON-related sessions. They include:

Wednesday, Sept. 25

• “Practical Strategies for Deploying FTTH” — John Bevilacqua (moderator), Kevin Noll (speaker)
• “A Photonic Future” — Alberto Campos (speaker)
• “Coherent PON” — Matt Schmitt (moderator), Haipeng Zhang (speaker)

Thursday, Sept. 26

• “Operationalizing and Automating PON” — Curtis Knittle (moderator), Jon Schnoor (speaker)
• “Boosting Performance: PNM for Optical Networks” — Jason Rupe (speaker)

Also, visit the CableLabs booth (#1547) on the TechExpo show floor to sit in on new technology demos and learn how CableLabs’ Technology Vision is helping align the broadband industry and advance innovation and technology development. A core focus area within the Tech Vision — Advanced Optics — encompasses our research to ensure that state-of-the-art optics solutions like those discussed here find their way into the evolution of our networks.

Please stay tuned as we continue to look at other advancements taking place in optical technology that the broadband industry should be keeping an eye on.