This module provides the student with an advanced understanding of the physical layer of optical transmission systems and networks on different time- and length-scales. Optical networks include the description of optical networks as a set of optical links, including the principle of wavelength routing on different time-scales (static and dynamic). On optical transmission the focus is on the elements of analysis and design of point-to-point opticallyamplified transmission systems as well as access applications. This provides in-depth understanding of optical transmission system design, optical amplifiers and amplified systems and the operation of wavelength division multiplexed systems. Both linear and nonlinear sources of transmission impairments and their accumulation with distance and interaction with dispersion are analysed. The choice of modulation formats, fibre dispersion and electronic processing techniques are discussed with the aim of maximising the spectral efficiency, channel capacity and operating system margins. Optical access networks, SDH/SONET, OTN, software defined networking (SDN) and data centre interconnect networks are covered.The concepts of routing and wavelength allocation algorithms.

At the end of the course, students are expected to:

Understand the principles of optically amplified optical transmission systems, power levels, noise accumulation and the trade-off between system capacity and reach
	Carry out power budget calculations for optically amplified links
	Understand signal transmission impairments: fibre dispersion, PMD, fibre nonlinearity, including Kerr nonlinearity and stimulated Raman scattering
	Carry out calculations quantifying the effects of dispersion and nonlinearity on an optical link
	Understand the concept of spectral efficiency; appreciate the difference between symbol rate and bitrate, and describe the use of different modulation formats and other signal dimensions to increase capacity (such as polarization and phase)
	Clearly understand optical system performance metrics: signal-to-noise ratio, sources of noise, capacity and spectral efficiency
	Understand trade-offs between optical systems capacity and reach, choice of modulation and detection formats, and implications on system performance
	Understand and apply the principles of electronic processing (transmitter and receiver based) and the basics of coherent detection
	Describe & analyse a variety of optical network architectures: access vs core, static vs dynamic operating on different time-and length-scales
	Analyse and design network topologies and calculate their capacities
	Have the knowledge and confidence to design optical communications links and networks on different time–and distance-scales
	Describe current research trends and explain expected future directions