Short Courses

The first half of the course will cover the design of data center optical links. We will describe the basic components of data center optical links and introduce the concept of the power budget including  power penalties and examine possible tradeoffs. We will continue with a discussion of component modelling  , first introducing simple models and example calculations, and then transition to more complex models and calculations. Finally, we will discuss various types of signal dependent noises in optical links.

The second half of this course will emphasize measurement tools and techniques to characterize signal quality and how well it is maintained when transmitted through a data center/short reach optical system. It will focus on bit-error-ratio (BER) analysis, and oscilloscope waveform analysis with emphasis on the NRZ and PAM4 eye diagrams, including TDEC and TDECQ. The basics for each measurement type will be covered, gradually building to the more difficult aspects of measurements, including common measurement problems and their solutions.. The test and measurement elements of the course will emphasize research and development as well as manufacturing of components and subsystems.  We will not discuss installation and maintenance test.

This course should 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
• Determine the relationships between BER and eye-diagrams tests.
• Avoid common mistakes that degrade measurement accuracy.
• Identify ways to increase test efficiencies.
• Develop test strategies to verify compliance to industry standards.
• Identify the similarities of and differences between classic TDP and new TDEC and TDECQ power penalty measurements

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. A basic knowledge of common laboratory measurement instrumentation will be helpful.

Greg LeCheminant holds B.S.E.E.T. (1983) and M.S.E.E. (1984) degrees from Brigham Young University. He began work for Keysight Technologies/Agilent Technologies/Hewlett-Packard in 1985 as a microwave circuits manufacturing development engineer. Since 1989, he has been involved in the development of measurement tools and applications for high-speed digital communications signals and systems with an emphasis in optical transmission.

Petar K. Pepeljugoski is a Senior Research Scientist at IBM Thomas J. Watson Research Center. He received B.Sc. from Ss. Cyril and Methodius University in Skopje, North Macedonia in 1982, M.S. from University of Belgrade, Serbia in 1986 and Ph.D. from the University of California at Berkeley in 1993. His work included design, modeling, prototyping and characterization of high-speed multimode fiber LAN links and parallel interconnects, as well as the use of equalization in electrical and optical links. Dr. Pepeljugoski was also involved in numerous 802.3 projects. He is an author or a coauthor of more than 70 journal or conference articles, and is a senior member of IEEE.