Design of Lightwave Communication Systems and

Networks

Objectives

• To introduce the basic physics of photonic devices and apply it for the design of optical transmission systems and networks.

• To simulate the various photonic components and also to do system level simulations.

• To study different noise processes in photonic circuits and understand their impact on Q-factor or BER.

• To develop engineering rules for the design of fiber-optic transmission systems.

Expectations

• My expectation:– Speak up.– Course as interactive as possible.

• Your expectations ?

Course Outline

• Review of electromagnetic theory - 1 lecture.• Fiber modes and pulse propagation in fibers – 3 lectures.

– Sec. 1 LP modes– Sec. 2 Fiber dispersion and fiber propagation

• Generation, amplification and detection of light - 4 lectures– Sec. 3 Semiconductor lasers and LED– Sec. 4 Amplifiers (SOA and EDFA )– Sec. 5 Photo-detectors

Course Outline

Point-to-point, single wavelength transmission system (2 lectures) Sec. 6 Functional Block (Transmitter and Receiver) Design Sec. 7 Penalties due to fiber dispersion and amplifier noise Sec. 8 System design with Tx, fiber, concatenated amplifiers and Rx

Eye Diagrams and Q-factor estimation Wavelength division multiplexed system (1 lecture)

Sec. 9 Add/drop multiplexers Sec. 10 cross-talk in WDM system

Linear cross-talk Nonlinear cross-talk due to four wave mixing

Optical Networks (1 lecture)Sec. 11 - SONET/SDH, circuit, packet and cell networks

Assessment

• Final exam – 50%

• Project - 50%– Each student will be assigned a project.

– The project involves• A good research survey.

• Simulation of a photonic device or a circuit.

• Project report.

History• Invention of Laser and Maser in 1960s

- In 1950s, Townes and Schawlow in the US and Basov and Prochorov in the USSR proposed to make use of stimulated emission for the construction of coherent optical sources.

– In 1960- Maiman demonstrated the first laser.– In 1970, Hayashi et al demonstrated GaAs semiconductor laser operating

at room temperature.• Low Loss Fibers in 1970s

– Fibers available in 1960s had losses in excess of 1000dB/km. – In 1970, Kapran, Keck and Maurer invented a low loss fiber with the loss

of 20 dB/km. – In 1979, Miya et al reported a loss of 0.2 dB/km near 1550 nm.

• Erbium Doped Fiber Amplifiers in 1980s.– In 1980s, Poole et al in the UK and Desurvire in the US demonstrated

light amplification by EDFA. Now it is used in all commercial long haul fiber optic networks.

Point-to-Point Optical Transmission System

2

N

1

Lasers Modulators Fiber Amp DEMUX Rx

UX

Contact Info

• Instructor: Dr. S. Kumar• E-mail: kumars@mail.ece.mcmaster.ca• Office hours: Wednesday 2-4 PM• Office: CRL #219• Web page of the course: www.ece.mcmaster.ca/faculty/~kumars/Lightwave_course.htm