A new wave of high-speed coherent optical components are expected gain widespread adoption in 2021, according to Dell’Oro analyst Jimmy Yu.

While vendors like Nokia, Ciena, and Infinera have been teasing faster and faster optics for years, Yu noted in a blog post that the optical transport market is a research and development heavy industry, with multi-year product cycles. “Grand ideas and proof of concepts announced years ago steadily build toward commercialization and main stream adoption over the course of a few years,” he wrote.

Yu said several long-hyped optical technologies, including those offering higher line rates up to 800 Gb/s, are likely reach the market in 2021.

“We are moving from the product introduction to the main stream deployment phase in many areas of the optical transport market,” Yu noted. “We believe the adoption curve for 600 Gb/s-capable line cards entered an inflection point and that it is positioned for rapid growth in 2021. We believe 800 Gb/s-capable line cards will also increase next year, considering the strong shipments so far with only one manufacturer.”

According to Yu, Ciena is unlikely to keep its lead in the 800 Gb/s space for long as more vendors enter volume production. “We predict that shipments of 600 Gb/s and 800 Gb/s-capable line cards will more than triple in 2021, and drive much of the capacity expansion in the year,” he wrote.

While Ciena remains the only vendor to date that has managed to launch its 800 Gb/s optics, Infinera has been aggressively trialing its own 800 Gb/s-capable line cards over the last year. The vendor's Infinite Capacity Engine 6 (ICE6) coherent optics entered field trials earlier this year, where it said it achieved headline data rates over a 950-kilometer span on a live production network. In June, Infinera trialed its sixth-generation optics that achieved 800 Gb/s line rates across a 730-kilometer stretch of Windstream’s network.

By comparison, Ciena’s WaveLogic 5 Extreme platform is limited to one or two span lengths, or roughly 80 to 240 kilometers, according to the company.

While Dell’Oro predicts that shipments of 600 Gb/s and 800 Gb/s optics will ramp up over the next year, that doesn’t mean customers will be looking to achieve peak line rates. Instead, Yu expects “the vast majority” of customers will be tuning the optics to supply 400 Gb/s wavelengths to metro, regional, and long haul networks.

Tuning optics down to lower line rates has a couple advantages. When operating at lower line rates, network operators can achieve connections over much longer distances. For example, Ciena claims its latest generation of optics can push a 600 Gb/s signal up to 1,000 kilometers, or a 400 Gb/s signal between 2,000 and 4,000 kilometers.

These is also a degree of compatibility involved, Yu adds. “We believe the use case for operating line cards at its highest modulation ... will be limited and that the higher usage will be at lower modulations,” he said, explaining that lower modulations will offer better performance for a given span.

Another contributing factor to 400 Gb/s becoming the dominant operating rate in 2021, is the rise of 400ZR pluggable optics for use in data center interconnect and metro applications. Because of this, “by the end of 2021, we predict that 400 Gb/s wavelengths will be in heavy demand in all parts of the optical network,” Yu said.

Nokia has leaned heavily into the 400 Gb/s pluggable market with the launch of its fifth-generation WaveFabric Elements optical portfolio this spring. The portfolio addressed both traditional line card-based transceivers and pluggable optics.

And in that vein, Telia tapped Acacia to merge its IP and optical network layers using a 400 Gb/s pluggable platform. Telia’s decision to deploy pluggable optics over more traditional transceivers was driven by the ability to use the former directly with standard routing platforms, explained Johan Gustawsson, Telia Carrier’s head network engineering and architecture, in a recent interview with SDxCentral.

Finally Dell’Oro anticipates that wavelength division multiplexing — a technology that enables multiple carrier signals to be transmitted over a single optical fiber — to see applications beyond the hyperscale market.

While the technology isn’t new, Yu argues that there is an opportunity to for internet content provider, multiple-system operators, and telecommunication operators to take advantage of the technology to improve network efficiency.