For instance, 3D Shaping is a key feature in the recently introduced Pico-powered AC1200, a 1.2Tb coherent transceiver module which supports two wavelengths up to 600G each. There are three elements to 3D shaping, with each providing a real-world benefit. There’s shaping of probability, shaping of location, and shaping of spectral width.

Senior Manager of Technical Marketing, Eugene Park, breaks down the elements of 3D shaping and what it means to Acacia’s technology. Learn more in our video.

Tom and Stephen discussed how network operators can turn unused margin gaps into usable capacity with Acacia’s innovative technology. As technological advances enable solutions approaching the theoretical Shannon capacity limit, gains are becoming more incremental, and reducing cost-per-bit is becoming more challenging. Acacia’s innovative technology and feature set enables a path to breaking through the optical terabit barrier allowing users of the technology to deliver optical networks with high performance while lowering cost and power for various network applications including long haul, metro, and DCI-edge.

In this video, Tom discusses how 3D Shaping enables fine-tune adjusting of the line-side coherent modulation characteristics helping network operators optimize capacity and reach for their network. This is enabled by Acacia’s Pico DSP which powers our AC1200 coherent module. You can watch Tom and Stephen’s full conversation below.

This interview was just one of the many conversations the Acacia team took part in at ECOC this year. We had a full schedule of thought leader presentations, AC1200 1.2T demonstration and customer and partner conversations. Check out our pre-ECOC blog post to learn more about what we were up to at the show.

Stay tuned to the blog for more updates on Acacia’s Pico DSP, AC1200 coherent module, and the rest of our technology portfolio.

In a few short days several members of the Acacia Communications team are scheduled to attend the annual European Conference on Optical Communication (ECOC) Conference and Exhibition at the Fiera Roma in Rome, Europe’s largest optical communications event. On the agenda for this year’s show are topics ranging from next-generation data centers to optics as an enabler for 5G. We are bringing a full team to talk to customers and partners and to learn more about the advancements our colleagues are making in optical communication technologies.

The 600G Era

We’re looking forward to discussing the progress of coherent optical technology and the industry transition to the 600G (per-wavelength) era which where capabilities, such as high-baud-rate optics, fine-tuned coherent transmission flexibility, and enhanced forward error correction (FEC) algorithms, are raising coherent performance to new levels.

In addition, today’s technology is designed to enable common coherent optical hardware to achieve the high-performance finesse of a long-distance link, the sheer raw capacity for shorter edge links, and scales to applications in between. This is the reason why some refer to the 600G era coherent technology as multi-haul technology since the same set of hardware can address long-haul, metro, and DCI-edge networks.

Learn more about the 600G era by reading “Fill Capacity Gaps in Your Optical Network” just published in the Autumn Edition of Optical Connections Magazine.

AC1200 600Gbps per Wavelength Coherent Transmission Demonstration

Acacia plans to show its AC1200 coherent module with dual-core design enabling 1.2 Tbps error-free transmission over fiber with 600 Gbps per wavelength coherent transmission. The AC1200 also features high-baud-rate high-performance capabilities as well as fine-tuning of the transmission using 3D Shaping which optimizes reach and capacity utilization. 600 Gbps performance requires DSP and optics technology with both high bandwidth and high performance. Acacia’s AC1200 module, which is based on its internally developed silicon photonics technology, uses advanced techniques to minimize implementation penalties and high-gain soft-decision forward error correction (FEC) to improve performance margin. Not only does this allow AC1200 to achieve high capacity 600 Gbps per wavelength transmission, with up to 1.2 Tbps, but it also results in improved performance at lower data rates, such as 200 Gbps and 400 Gbps, compared to existing solutions.

Plug coherent in edge and access

Also at the show, we expect to hear a lot of discussion around advances in coherent technology to help meet growing bandwidth demand beyond the core. Today, coherent is moving from metro core to access aggregation networks. The industry is working to standardize coherent solutions for even shorter reach interfaces including two new specifications recently announced by CableLabs that are the result of a focused effort to develop coherent optics technology for the access network and bring it to market quickly.

We look forward to discussing Acacia’s participation in the industry organizations such as Optical Internetworking Forum (OIF), IEEE, and Cable Labs and the trend towards using coherent solutions such as Acacia’s award-winning CFP2 for shorter distances.

Acacia Communications’ Thought Leaders to Present

In addition, Acacia Communications experts plan to lead discussions and share knowledge covering topics such as Digital Signal Processing (DSP), subsea communications, and lab automation. See below for a complete listing of who, when, where and what each plans to share with ECOC attendees:

Sunday, September 23, 2018

• 9:00-12:30 – Timo Pfau, principal DSP engineer, will present on “What can DSP bring to optical access” in the DSP for Next Generation Optical Access Workshop.
• 9:00-12:30 – Christian Rasmussen, founder and vice president of digital signal processing and optics, will share his thoughts on the “Future scaling and capabilities of DSP algorithms” in the Coherent DSP in Optical Communications Workshop.
• 9:00-12:30 – Hongbin Zhang, principal DSP engineer, will present on the “Future of transponders for submarine transmission” in the Submarine Systems Workshop.

Tuesday, September 25, 2018

• 1:30 – 3:00 p.m. – BinBin Guan, optical engineer, will lead the Lab Automation Hackathon in which there will be eight demonstrations for various common lab automation tasks.

Wednesday, September 25, 2018

• 1:30 p.m. – Timo Pfau will present his invited paper titled, “High performance coherent ASIC” as part of the SC3 – Digital Signal Handling Techniques for Optical Communication Systems session.

Our team of experts is available to discuss Acacia Communications’ latest innovations in optical interconnect solutions. If you’d like to meet with Acacia at ECOC, contact us. We’d love your feedback!

Coherent transmission w/ varying baud rates and modulation modes applicable to multiple types of networks has been referred to as multi-haul, as described in the OFC 2018 Show Report. A ROADM-rich network design is typically attributed to traditional metro networks. However, with the rise of multi-haul capable coherent technology, the lines between what is considered metro and long haul are sometimes blurred. A previous blog post provided a brief tutorial of coherent optical communications and how it is applied to long-haul, DCI, and metro networks. I encourage you to read that post as it provides a good background for this blog post.

A benefit of coherent optical transmission is that the bandwidth capacity of a link can be increased by moving to a higher modulation order (e.g, from 2-bits/symbol QPSK to 4-bits/symbol 16QAM), as long as there is sufficient optical signal-to-noise ratio (OSNR) margin to overcome the resulting penalty. Acacia’s patented Fractional QAM (F-QAM) provides a higher level of granularity compared to traditional quantized integer-bits/symbol modulation orders, by enabling non-integer bits-per-symbol (e.g, 3.3 bits/symbol) modulation, to better optimize link capacity. Another adjustable “knob” to increase capacity is the transmission baud rate, which directly varies the spectral width of the signal. Similar to traditional quantized modulation orders, coherent technology has previously implemented quantized baud rates. However, these quantized baud rates may result in sub-optimal use of the available channel bandwidth—that is, the spectral width of the transmission does not fill up the channel’s available passband. Adaptive Baud Rate provides the granularity to enable increased optimization of the available passband. F-QAM and Adaptive Baud Rate are elements of the Acacia AC1200 coherent transponder module’s 3D shaping capability.

In a multi-haul network where optical transmission between end points may encounter numerous cascaded optical filters, one challenge is to spectrally optimize the optical transmission to fit within the aggregate passband of these filters from either fixed or reconfigurable add/drops of the network’s line system, as shown in Figure 1.

Figure 1. Spectrally quantized transmission may leave spectral gaps in aggregate passband.

As previously mentioned, quantized baud rates may not allow enough flexibility and granularity to fill up the passband. However, by using Adaptive Baud Rate, the capacity can be increased to more closely match the available spectrum within the aggregate passband of the cascaded filters with fine granularity, as shown in Figure 2.

Figure 2. Acacia’s Adaptive Baud Rate can optimize the spectral transmission to more closely match the available aggregate passband spectrum.

The aggregate passband of the cascaded filters contributes to the upper bound limit of capacity increase one can achieve in a multi-haul network optical link. In this case, I am not referring to the theoretical Shannon Limit. Rather, I am referring to the practical passband constraints that come from the implementation in a network of cascaded imperfect optical filter passbands due to variations of the filter conditions. Variations may become more prevalent if the optical transmission passes through a multi-vendor line system environment, a potential situation in a disaggregated network architecture. Having the ability to vary modulation and baud rate allows for maximal flexibility in optimizing the transmission to more closely match the line system’s available passband, as opposed to matching the line system to the terminal equipment’s optical characteristics.

As previously mentioned, Acacia’s 3D Shaping capability, as illustrated in Figure 3, enables the “dialing-in” of both modulation mode and baud rate.

Figure 3. Acacia’s 3D shaping capability enables optimization of link capacity and reach; shaping of spectral width is achieved using Adaptive Baud Rate. 

This capability equates to the ability of the optical transmission spectrally “molding itself” to the line system’s passband on a link-by-link basis. By using 3D Shaping, to a certain extent the coherent DWDM source can be decoupled from the line system since the optical transmission is optimized regardless of the pass band characteristics of the line system. This capability lends itself nicely to the disaggregation of terminal equipment and line systems.

Whether multi-haul networks use flexible ROADM architectures with flexible passbands or architectures with fixed grid spacing (50GHz, 75GHz, 100GHz), the AC1200 with 3D Shaping can be used to optimize capacity with any of these type of line systems.