• Technical Conference:  30 March – 03 April 2025
  • Exhibition: 01 – 03 April 2025
  • Moscone Center, San Francisco, California, USA

SC341 - Sub-carrier Modulation and Superchannels for Terabit-class DWDM Transceivers

Monday, 25 March
08:30 - 12:30 (Pacific Time (US & Canada), UTC - 08:00)

Short Course Level: Intermediate (comprehensive understanding of optical transport systems is necessary to follow course material)


Sander L. Jansen¹, Dirk van den Borne²; ¹Adtran Optical, Germany; ²Juniper Networks, Germany

Short Course Description:

Over the past 15 years, advanced digital signal processing and record-high baud rates have been instrumental in pushing the limits of DWDM transport. State-of-the-art DWDM transceivers supporting baud rates of 140 Gbaud are now deployed worldwide, enabling 1.2T single-carrier transmission over short-reach distances and 600G/800G over regional and long-haul links. Next-generation transceivers will likely be based on 3 nm CMOS technology, with higher sample rate DAC/ADCs that can engineer a wider spectrum, and ever tighter integration between DSP and optics. All combined, this will enable transceivers with baud rates up to 200 Gbaud. Such transceivers can be used for 1.6T single-carrier transmission over short-reach distances, and over 800G/1.2T for longer links.

But is this fast enough? Next-generation Ethernet standardization, up to 1.6TE, is well under way in the IEEE, and pluggable client optics are already evolving to 1.6T - with technologies enabling 3.2T on the horizon. What is the impact on DWDM transport systems when Ethernet rates start to outstrip single-carrier data rates? Will the use of Superchannels and/or optical sub-carriers become unavoidable to accommodate the ever-higher client data rates?

Higher Ethernet rates have as well an impact on the network edge, for example in access and aggregation. High-speed Ethernet ports are often broken out into multiple lower speed interfaces in this part of the network, which can be extended to DWDM interfaces using subcarrier modulation. This might open up novel applications for DWDM transport, such as point-to-multipoint transmission.

This short course will focus in detail on how to realize terabit-class DWDM transport systems. We will look in detail into the limits of single-carrier transport in terms of optical system performance and the development of critical components such as DAC/ADCs, modulators, and receivers. We discuss the advantages and disadvantages of Superchannels and spectral engineering with sub-carrier modulation for both point-to-point and point-to-multipoint transport. We take a broad view, exploring all aspects of system design, including optical components, transmission impairments and the trade-off between optical performance and system complexity / cost.

Short Course Benefits:

After attending this short course, you should be enable:

  • Describe how Ethernet standards and pluggable optics are evolving to 1.6TE and beyond, and what the implications of such next-generation standards are for optical transport.
  • Understand the latest developments in high-speed ADC/DAC and tighter electro-optical integration that are enabling Terabit-class DWDM transceivers.
  • Provide an overview, and be able to describe, the design challenges for the opto-electric components at around 200 Gbaud and beyond, that are key in enabling high baud-rate coherent systems.
  • Understand the concept of optical Superchannels, how this technology has evolved over the years, and provide a detailed overview of their advantages and disadvantages.
  • List different flavors of sub-carrier modulation, including the relevant modulation and detection concepts, and understand their respective advantages and disadvantages.
  • Be able to explain how sub-carrier modulation formats can be used to optimize the nonlinear tolerance in long-haul transmission systems by optimizing the baud rate depending on the properties of a transmission link.
  • Describe how sub-carrier modulation formats can play a role in cost-effective short-reach systems, including for point-to-multipoint network architectures.
Short Course Audience:

This course is intended for engineers, researchers and technical managers who would like to gain a better understanding about the system design trade-offs in Terabit-class transceivers and DWDM transport. We focus especially on the benefits of technologies such as sub-carrier modulation and Superchannels in the realization of next-generation optical transport systems and architectures. Apart from the theory and concepts, we will detail the most relevant applications of this technology in different segments of the optical transport network. Participants should have a comprehensive knowledge in the field of fiber-optic transmission systems as well as optical modulation and detection; no previous knowledge of sub-carrier modulation techniques is required.

Instructor Biography:

Sander L. Jansen is vice-president and general manager for the infrastructure monitoring BU at Adtran Optical in Munich, Germany. Prior to Adtran, Sander was a technical team lead of the optical components group at Nokia Siemens Networks, responsible for the evaluation and specification of new optical components.
He received his Ph.D. degree with highest honors in electronic engineering from Eindhoven University of Technology. Sander authored and co-authored 10+ patents, one book chapter and more than 100 refereed papers and conference contributions. He has received several awards including the Young Investigator award from the IEEE Photonics Society.


Dirk van den Borne is a director of system engineering at Juniper Networks, where he leads a team of solution architects that advise operators on technology evolution across routing, transport, data center, campus and security. He specializes himself in the convergence of IP/MPLS and transport, and how developments in Ethernet, optical integration, and telemetry/analytics are shaping network architectures.

Dirk obtained his Ph.D. in optical communications from the Eindhoven University of Technology. He has spoken frequently at major industry events, authored and co-authored over 100 peer-reviewed journal and conference contributions and holds several patents on optical communication. He served on various technical program committees, including currently on the OFC committee. He is based in Munich, Germany.