75495 - Optical Circuits And Networks M

Learning outcomes

This course consists of two modules to provide skills in optical circuit design and its deployment in future optical network elements and infrastructures. The first module is related to the design of optical circuits in view of their applications in optical networks, by the introduction of a circuit model approach based on the physical principles of optical devices. Basic skills in optical networking and in practical applications of optical circuits are given in the second module, with reference to evolving and emerging network service scenarios.

Course contents

First module (3 CFU)

• Introduction: from materials to optical circuits.
• Materials: main features of Glasses, Lithium Niobate, Silicon and III-V semiconductors.
• Technologies: the generic foundry model.
• Electromagnetic behavior of optical waveguides: types of waveguides, modes, effective and group indexes, phase and group velocities, different kinds of losses.
• Inductive approach to the behavior of some simple optical components: straight and curved waveguides, couplers.
• Inductive approach to the behavior of some composite Optical Circuits: Mach-Zehnder interferometers, Ring resonators.

Second module (3 CFU)

• Recall of some mathematical tools: Fourier and z-transforms and matrix circuit descriptions (Scattering matrix and Transmission matrix).
• Deductive approach to the behavior of some composite Optical Circuits: Mach-Zehnder interferometers, Ring resonators, Y-junctions, Arrayed Waveguides (AWG), etc.
• Deductive approach to more complex devices: Non Recursive and Recursive devices.
• Cascade of two ports optical devices, Transfer Function.
• Tunable and Programmable optical devices for Programmable Optical Networks.
• A first example: an optical filter tunable both in central wavelength and transmission bandwidth.

In A.A. 2018/2019 the following visiting professors on Erasmus mobility will present recent applications of optical circuits and networks

Prof. Jos van Der Tol, Technical Unversity Eindoven

Readings/Bibliography

Textbook: Lecture notes available at http://iol.unibo.it/ (access with student's UniBo username and password)

Further reading:
C. K. Madsen, J. H. Zhao, Optical Filter Design and Analysis. A Signal Processing Approach, J. Wiley & Sons, Inc, 1999

L. Chrostowski, M. Hochberg, Silicon Photonics Design. From devices to systems. Cambridge University Press, 2015

L. Vivien, L. Pavesi, Handbook of Silicon Photonics, CRC Press, 2013

Teaching methods

During lecture hours, the main features of integrated optical components necessary to realize optical Networks and Data Centers will be illustrated, considering both technological and functional aspects.

Starting from basic electromagnetic concepts of guided propagation, the behavior of simple optical circuits will be illustrated first, keeping attention to material properties and technological aspects. Such basic circuits will be combined to realize more complicated optical devices, with a bottom up procedure. This will show that it is not possible to increase too much the circuit complexity and still easily obtain results. A top down, functional, approach will be then introduced, showing that it can be successfully used to describe the circuits introduced so far and even more complicated ones, with features which can be programmed using suitable external controls.

Practice hours show examples of application of the theoretical ideas illustrated during lectures, running simple Matlab codes. Students will actively contribute to this part, presenting short seminars on topics agreed with the teacher.

At the end of the course, students will know how to describe the electromagnetic as well as the functional behavior of integrated optical circuits also considering basic effects of possible technological choices. This will allow them not only to design such devices but also to be able to discuss about the most suitable technology to fabricate them.

Assessment methods

The exam is oral.

Questions will be asked to the students aiming to check the knowledge and the understanding of the general principles of the studied topics and the ability of discuss them with propriety of language.

Teaching tools

Lecture notes.

To allow active participation of students to the course, some simple Matlab codes will be provided to students, who will be asked to use them to prepare and give some short informal seminars to their colleagues on some topics agreed with the Course Instructor. This will allow students to immediately apply the introduced concepts and analyze the role and the effects of the device parameters.

Matlab can be freely downloaded and installed by UniBo Students in the framework of the agreement between UniBo and Mathoworks at this link.

Office hours

See the website of Paolo Bassi