SC428 - Link Design and Modeling for Intra Data Center Optical Interconnects

Sunday, 06 March
17:00 - 20:00

Short Course Level: Beginner and Advanced Beginner


Petar Pepeljugoski, IBM Research, USA

Short Course Description:

Short reach optical interconnects using multimode fibers and VCSELs comprise the vast majority of all links deployed in data centers and supercomputers due to their low cost and power consumption. The optical interconnects fill the intermediate space between electrical interconnects (<5m) and single mode fibers (>300m). To maintain the low cost, the link power and jitter budget has to be structured in a way to provide the optimal trade-off between the individual link components and their specifications.
The primary objective of this course is to provide the participants with an introductory knowledge in link design. We will discuss the possible approaches to link design and go in depth over the individual link penalties and losses and noises.

The course will include in-depth coverage of signal propagation in multimode fibers (laser launch conditions, fiber DMD), effects of various signal dependent types of noise (mode partition noise, modal noise, relative intensity noise) and their impact on the link performance. We will include discussion of connector effects (mode mixing). We will also discuss the measurement methodologies used to specify the modern multimode fibers and sources operating at 850nm.

We will also discuss advanced modulation formats (PAM-4, DMT) and their applicability to short optical interconnects.

Short Course Benefits:

This course will enable you to:

  • Understand the components of intra data center optical links
  • Describe the basic elements of power budget and possible trade-offs
  • Evaluate and choose suitable models for various components of the link (SMF or MMF) to be used in the design phase
  • Learn how to write and setup your own component models to integrate with commercial link simulators
  • Get in depth insight in multimode fiber propagation, including launch conditions and connector effects and understand of impact of signal dependent noises in multimode and single mode fiber links
  • Discuss single mode fiber propagation and the impact of signal dependent noises specific to single mode fiber links
  • Discuss the advantages and disadvantages of advanced modulation formats in data center optical interconnects
Short Course Audience:

This beginner-intermediate course is intended for engineers and scientists working on intra data center optical interconnects as well as those working on components and subsystems interested in developing an expertise in link design. The course also addresses academic researchers and graduate students with basic knowledge on multimode and single mode fiber modeling and propagation, and link power budgeting. Some basic understanding of optical communication systems is helpful, but is not a pre-requisite.

Instructor Biography:

Petar Pepeljugoski joined IBM Research as a Research Staff Member in 1994 after receiving his Ph.D. from University of California at Berkeley. His research work included design, modeling, prototyping, and characterization of MMF LAN links and parallel interconnects for use in IBM servers and systems. He was involved in the development of several Ethernet (IEEE 802.3z, IEEE 802.3ae, IEEE 802.3aq, IEEE 802.3ba) standards, as well as the development of the specification of the OM3 fiber. Dr. Pepeljugoski is an author or coauthor of more than 60 journal or conference articles and is a Senior Member of IEEE.