The Optical Networking and Communication
Conference & Exhibition

Los Angeles Convention Center,
Los Angeles, California, USA

Short Courses

SC408 - Space Division Multiplexing in Optical Fibers

Monday, 20 March
08:30 - 12:30

Short Course Level: Advanced Beginner


Roland Ryf; Bell Labs, Alcate-Lucent

Short Course Description:

The course provides the background and the principles necessary to understand the transmission of multiple optical signal channels over a single optical fiber by using spatially diverse light paths (space-division multiplexing).
The course teaches methods and techniques to design and model the propagation of light carrying multiple spatial channels in optical fibers, and also in optical components like mode couplers, splitters, wavelength-selective switches, and multimode amplifiers. A special emphasis is placed on the description of the optical elements as multiple-input- multiple-output-port devices by applying the mathematical framework of linear system theory and experimental methods to measure the complete amplitude transfer matrix of the components are presented.
The course builds up from simple components to complete transmission systems and covers the basic multiple-input multiple-output digital signal processing techniques required to recover the transmitted signals. Strategies to minimize the complexity of digital signal processing, like differential group-delay compensation or intentional introduction of strong coupling between the light paths are presented and discussed and compared to experimental long distance transmission results.
The course is heavily based on real life examples; in particular it covers following topics: coupled and uncoupled multi-core fibers, multimode fibers with step-index and graded index profiles, phase-plate-based mode couplers, spot based couplers, 3D-waveguide and photonic lantern based couplers, distributed Raman amplification, Erbium doped fiber amplifiers, and wavelength selective switches for multimode and multi-core fibers.

Short Course Benefits:

This course should enable participants to:

• Compare space-division multiplexing to other multiplexing techniques, and list key advantages and potential fields of application

• Summarize key advantages and limitations of different fiber types for space-division multiplexing

• Explain the origin of coupling or cross-talk between light paths in multi-mode and multi-core fibers

• Measure components with multiple-input and/or  multiple-output ports and extract key parameters like mode-dependent loss and differential group delay

• List the key principles used to build mode-couplers and how the insertion loss and the  mode dependent loss scale as function of number of modes

• Design optical components that support multiple modes and explain how the basic design differs from single-mode components

• Describe digital signal processing techniques to calculate bit-error rate and multiple-input multiple-output impulse responses from raw receiver data

• Discuss strategies to reduce the complexity of the receiver digital signal processing in space-division multiplexed transmission


Short Course Audience:

This course is intended for engineers, scientists, managers, technicians and students who want to understand space-division multiplexing in optical fibers. Basic knowledge of optics is assumed and basic math knowledge in linear algebra and differential equations is suggested. By the end of the course, the presented techniques will allow the partecipant to design and analyse  simple space-division multiplexed systems.

Instructor Biography:

Roland Ryf is a distinguished member of technical staff in Photonic Subsystems Research at Nokia Bell Labs, Holmdel, NJ, where he is working on photonic technologies for switching, filtering, and amplification in optical communication systems. In particular he has been working on the design and prototyping of microelectromechanical systems (MEMS) and liquid crystal on Silicon (LCOS) based free space devices.  Most recently he has been working on space-division multiplexing (SDM) in optical fibers and record-breaking demonstration of optical multiple-input multiple-output (MIMO) long distance transmission in coupled multi-core fibers and multi-mode fibers.

Sponsored by: