Acacia’s Leadership in Optical Interconnect Technology
All it takes is a quick glance at the patent wall in our Maynard, Massachusetts office to see the scope of innovation Acacia has delivered since its founding in 2009. As a pioneer in coherent optical technology, our vision was clear: Deliver silicon-based interconnects that transform cloud and communication networks by simplifying these networks, digitizing numerous complex analog functions, and providing significant improvements in speed, capacity, and power consumption​.

Patent WallFigure 1. Acacia’s Wall of Patents.

A recent Gazettabyte article details how our co-founders carried out this mission, introducing improvements in performance and power consumption to legacy coherent technology, initially used for the most challenging optical transmission links. Looking through our history, it’s clear to see the trailblazing path Acacia helped to define with coherent optical modules, especially pluggable modules. Acacia has always been laser-focused on providing customers with continuous improvements in speed, capacity, performance, size, and power consumption to meet the ever-growing demand for bandwidth. This has been done by focusing on (1) silicon-based optical and electrical designs, (2) advanced digital signal processing (DSP), (3) high-speed RF expertise, and (4) volume manufacturable high-density packaging, with all these disciplines “under one roof.” As a result, Acacia is now a leading supplier of coherent modules with multiple product families to support speeds from 100G to 1.2T, including a broad portfolio of 400G and 800G pluggable products, to address the needs of network operators worldwide.

Pioneer of Coherent Pluggables
It is interesting to note that this year marks the 30th anniversary of a significant event in optical transceiver history. It was in 1995 when the first standards-based pluggable optical transceiver called the Gigabit Interface Convertor (GBIC) was first defined, with supported speeds up to ~1Gbps. It was ~20 years from this achievement that Acacia introduced the first optical coherent pluggable transceiver to support 100Gbps in the multi-source agreement (MSA) CFP form factor.

Industry standardized pluggable modulesFigure 2. Industry standardized pluggable modules: From the early days of 1G GBICs to today’s coherent pluggables capable of 3000km+ 400G and 1000km+ 800G.

And today, Acacia’s latest generation of coherent pluggable modules powered by the Delphi DSP, our 9th generation DSP, has enabled extraordinary reaches using even smaller QSFP-DD and OSFP form-factor modules. Acacia’s 400G ultra long-haul modules support distances beyond 3000km, and 800G ZR+ enhanced performance modules support distances beyond 1000km.

Leadership in Industry Standards
To ensure a thriving marketplace for coherent pluggable optics, many companies participate in MSA initiatives and/or in industry standards groups to agree on module product requirements to ensure a multi-vendor supply, interoperability, and economies of scale. Acacia has been a key driver and participant in many of these organizations. In the 400G pluggable generation, Acacia served as editor for the 400ZR Implementation Agreement in OIF. Acacia was also a founding member of the OpenZR+ MSA, which provided requirements for enhanced performance 400ZR+ with multi-vendor interoperability. Market adoption of 400ZR and OpenZR+ solutions has been the fastest of any coherent technology in history.

In the 800G pluggables generation, Acacia has continued its leadership in industry standards activities. As a key contributor along with other coherent suppliers, Acacia introduced the first standardized, interoperable probabilistic constellation shaping (PCS) mode for 800G ZR+ enhanced performance, enabling network operators to expand their 800G reaches beyond 1000km. The company is also playing a key role in driving 1600ZR/ZR+ industry agreements.

With the increasing demand for the current generations of 400G and 800G coherent pluggable modules, several companies have jumped on the bandwagon to participate in this optical renaissance. These 400G and 800G QSFP-DD and OSFP form-factor modules, capable of plugging directly into switch and router ports, have invigorated architectures using router-based coherent optics as a networking solution to reduce overall total cost of ownership.

Silicon-based Designs, Advanced DSPs, and High-Density Packaging
The key to Acacia becoming a market leader in coherent optics stems from our ongoing focus on core technology. For example, an important factor that provided many advantages in low power and high-density packaging was Acacia’s adoption of silicon photonics for high-speed coherent transmission. Silicon does not require temperature stabilization, which results in lower power implementation. In addition, silicon photonics can leverage high-volume CMOS packaging techniques to reduce overall cost. Our design and development approach has always been to utilize silicon photonics for both MSA pluggable modules as well as performance-optimized modules, providing design and operational efficiencies as well as rapid time to market. Following Acacia’s lead, we are now seeing multiple suppliers also embracing silicon photonics technology in their coherent pluggable modules because of the benefits it has delivered to the industry.

Another key technology advantage that sets Acacia apart is its coherent DSP design and capabilities. Innovation in this area has been critical for mitigating impairments such as dispersion and non-linear effects incurred during transmission over optical fiber. Acacia’s balanced and power-efficient approach to DSP development ensures robust algorithms while minimizing power consumption. As CMOS node sizes continue to shrink, relatively complex techniques for improving performance can be introduced into very compact MSA pluggable modules. The improved performance is enabling network operators to expand the types of architectures they can deploy using these pluggables, resulting in the ability to offer a wider range of network applications.

Driving innovation to meet increasing transmission baud rates meant having in-house cross-disciplinary teams to ensure the best designs. We were able to achieve this while also delivering a compact low power consumption device. Acacia’s 3D Siliconization enabled this high-density level of packaging with high signal integrity and allowed us to also leverage volume manufacturable processes used in the electronics industry. This approach enabled faster scaling of manufacturing and improved reliability.

15+ Years of Industry Firsts and Design Expertise
Technology leadership is a culmination of many factors, not just having the expertise in the technology itself. It is comprised of how the technology is developed and quickly brought to market with the capability of volume while maintaining quality, and with the goal of meeting customer requirements. Many factors have contributed to Acacia’s technology leadership, including an engineering approach based on in-house design expertise across key disciplines, leveraging years of experience, building on the successes of previous generations as well as adjacent industry innovations and manufacturing processes, and participating in industry standards. This powerful combination created many industry firsts over the last 15+ years since Acacia was founded.

Figure 3. Acacia has achieved many industry firsts for coherent pluggable modules since its founding.

Acacia has introduced coherent module products, including its recent Delphi-based pluggable modules, leveraging nine generations of DSP ASICs, and holds an industry leadership position when it comes to innovative design, quality, and manufacturability of coherent pluggable modules especially as baud rates increase while size and power consumption requirements decrease. Acacia continues to demonstrate its technology leadership as we move to higher bandwidth applications such as AI, as well as customer requirements for higher speed solutions such as 1600G MSA pluggable modules.