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ELEC0109 Advanced Photonic DevicesÌý

Course Summary:

To provide an in-depth understanding of the design, operation and performance of advanced photonic devices including light emitting diodes, LEDs, a range of semiconductor lasers, photodetectors, liquid crystal devices, photovoltaic solar cells for a variety of applications including optical communications and solar power generation.

AHEP 4.0 Learning Outcomes

M1: Apply knowledge of mathematics, statistics, natural science, and engineering principles to the solution of complex problems. Much of the knowledge will be at the forefront of the subject of study and informed by a critical awareness of new developments and the wider context of engineering.

M2: Formulate and analyse complex problems to reach substantiated conclusions. This will involve evaluating available data using first principles of mathematics, statistics, natural science, and engineering principles, and using engineering judgement to work with information that may be uncertain or incomplete, discussing the limitations of the techniques employed.

M3: Select and apply appropriate computational and analytical techniques to model complex problems, discussing the limitations of the techniques employed.

M4: Select and critically evaluate technical literature and other sources of information to solve complex problems.

M5: Design solutions for complex problems that evidence some originality and meet a combination of societal, user, business and customer needs as appropriate. This will involve a consideration of applicable health and safety, diversity, inclusion, cultural, societal, environmental and commercial matters, codes of practice and industry standards.

M7: Evaluate the environmental and societal impact of solutions to complex problems (to include the entire life-cycle of a product or process) and minimise adverse impacts.

M17: Communicate effectively on complex engineering matters with technical and non-technical audiences, evaluating the effectiveness of the methods used.

Complex problemsÌýhave no obvious solution and may involve wide-ranging or conflicting technical issues and/or user needs that can be addressed through creativity and the resourceful application of engineering science.

Detailed Learning Outcomes

On completion of this course, students should be able to:

• Know and understand the scientific principles and method of light generation, detection, and modulation and to use this to understand the operation and evolution of advanced photonic devices so that they can appreciate historical, current, and future developments and technologies.
• Have a comprehensive understanding of the scientific principles of light generation, detection, and modulation and to use this to understand the operation and evolution of advanced photonic devices and their use in telecommunications and in solar power generation.
• Know and understand the mathematical principles necessary to underpin their education in advanced photonic devices and apply mathematical methods, tools and notations proficiently in the analysis and solution of engineering problems.
• Be aware of developing technologies related to advanced photonic devices.
• Apply and integrate knowledge and understanding of other engineering disciplines to support study of their own engineering discipline.
• Know and understand mathematical and computer models relevant to the engineering discipline, and an appreciation of their limitations.
• Understand concepts from a range of areas including some outside engineering such as from physics and chemistry, and the ability to apply them effectively in engineering projects.
• Understand engineering principles and can apply them to analyse key engineering processes. · Use fundamental knowledge of device materials and device fabrication to investigate new and emerging technologies.
• Find, classify, and describe the performance of systems and components using analytical methods and modelling techniques.
• Work with technical uncertainty.

Course Content:

Photonic materials and properties

Glass; Crystals; Rare Earth-doping; Semiconductors; Nanotechnology, Bulk; Quantum Wells, Nanowires, Quantum Dots; Liquid Crystal Photon absorption; Homo-structure; Hetero-structure; Spontaneous emission; Stimulated emission; Non-radiative decay; Energy bands; Band Offsets; Optical Gain; Lasing Condition; Labelling of Modes; Near Field; Far Field; Temperature Dependence; Density of states; Fermi level; Quasi-Fermi levels; Direct and Indirect Bandgaps States in the gap; impurities and defects; Carrier recombination; Non-Radiative recombination; Radiative recombination; Radiative efficiencies; Lifetimes; Electro-optic refractive index modulation: CIE, Plasma effect, QCSE; Non-linearities, Molecular Beam Epitaxy

LEDs, lasers, amplifiers and optical filters

Historical Development of Semiconductor Lasers; Gratings; Laser Structures; Fabrication techniques (Fibre and Semiconductors); Photonic Band gap structures, The rate equation model; Optical Confinement Factor; spectral linewidth; LEDs; Amplifiers; Lasers; Fabry Perot cavity; Ring cavity; Laser Noise, Frequency Chirping; Laser examples: VCSEL, DFB, DBR, External Cavity; Relaxation Resonance; Relaxation Oscillation; Turn-on Delay; Damping; Laser direct modulation; Laser Characteristics; Semiconductor laser fabrication (Waveguide, vertical cavity)

Photodetectors (optional)

Liquid Crystal Photonic Devices

Physical properties of liquid crystal materials in the context of phase and amplitude modulation of light; polarisation and phase modulation; diffractive elements; optical filters; application of diffraction and optical filters using liquid crystals; device structures; analysis of the performance in relation to various applications.

1. The main aims of the course and how it links to earlier courses you may have studied

The course teaches fundamental physics as well as device design and system applications, so it is wide ranging and in that sense this course is difficult. To fully understand a device, you need to think of it in multiple ways at the same time which is a second reason it is difficult: Physical 3D structure, material behaviour, energy levels of electrons and holes in the material, spectrum of generated light, time domain response, spatial distribution of light in 3D, modulation speed characteristics, the way the material affects the polarisation of light. This course teaches the fundamental physical principles of semiconductor materials and liquid crystal materials and the interaction of light with them, including light generation, modulation, and detection. The course also teaches the principles of device design to make use of the physical behaviour of the materials to maximise their performance and efficiency as well as minimising any disadvantages or problems associated with the physical behaviour of the materials. Many of the devices are related to optical fibre communications. We explain how LEDs and Lasers work and can be designed. The course includes advanced mathematics including linear algebra, linear systems theory, convolution theory, 3D Fourier Transforms, rate equations and briefly makes use of coupled wave equations and perturbation theory. After studying this course, you will be able to understand and analyse research papers written for PhD students and other researchers and professors. You will be able to design your own optical devices for particular applications.Ìý

1. Where it is relevant? Does the course have clear links to particular industries or careers?

Past students who took this course are now deans and professors at universities around the world or lead development and research groups at major companies. Several of the professors in our department took this course when they were students, and their research is now in the subject area of this course in which they have become world leading researchers as they became excited by the topics being taught. Several students who took this course went on to design/invent new types of laser. This course has clear links to UK and international industries involved in semiconductor manufacturing and growth, photolithographic manufacturing of silicon chips, lens and mirror manufacturing, laser, optical modulator and photodiode manufacturing and in their use in optical fibre communication systems, connectors to couple lasers and optical fibres, laser scanning LIDAR hardware and software, precision metrology, displays, virtual reality goggles, 3D data processing, object recognition, hidden optical security features for banknotes, concert tickets and driving licences, nanostructured surfaces for self-cleaning windows, autonomous vehicle 3D vision systems, astronomical telescopes, design of endoscopes for viewing and destroying tumours.Ìý

1. Method of delivery for this year

The main form of delivery will be by in-person lectures with zoom or previously recorded short video segments as a backup in case of illness or unexpected circumstances. We aim to record lectures using Lecturcast for remote students to view. The work to be conducted each week is specified on the Moodle site including directed reading, online books and past years assessments and exam papers to try.Ìý

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1. What is the form of assessment for this module?

This module is assessed by a 15% weighted coursework and an 85% weighted exam. The material taught in the module builds the foundational knowledge, understanding and techniques enabling students to understand recent research advances. The coursework is a novel form of assessment as the students are directed to research papers which they must read and analyse, to show that they can understand them. In past years, the research papers have been in top peer reviewed journals, or recently published or are power point slides presented by researchers at conferences or are papers we published on our research.Ìý

1. Who will be teaching on the course and their (research) interests linked to the course?

The lecturers and professors teaching the course are conducting world leading research in the topics of the course and so are fascinated and excited by the interactions of light and materials and are very keen for you to join them in their research groups as PhD students if you also find this subject enthralling and can achieve high marks in this course. Our interests extend from fundamental physics to applied optical engineering in industry.

Professor David R. Selviah is the module leader and has taught at Ïã¸ÛÁùºÏ²ÊÖÐÌØÍø for over 35 years. For 10 years he designed electronic devices, fabricated them in clean rooms and assessed them in industry and in universities. His research has been mainly in collaboration with many different industries and includes laser scanning LIDAR for modelling 3D environments, precision location and tracking of mobile phones indoors, 3D alignment, 3D object segmentation and classification.Ìý

Dr Mingchu TangÌýis a Lecturer in the Department of Electronic and Electrical Engineering at Ïã¸ÛÁùºÏ²ÊÖÐÌØÍø. His research interests include: Molecular Beam Epitaxy growth of Semiconductor materials with Quantum Dots for use in lasers and solar cells. He has 145 papers in internationally leading journals and conferences, some jointly with Professor Huiyun Liu and Professor David Selviah.

Professor Huiyun Liu was awarded Royal Society University Research Fellow and started his academic career by taking Senior Lecturer at University College London with commissioning the first new Molecular Beam Epitaxy Facility in central London in 2007. He was promoted as Professor of Semiconductor Photonics in 2012. He has more than 20 years of experience on the nanometre-scale engineering of low-dimensional semiconductor structures, including quantum wells, quantum dots and nanowires by using Molecular Beam Epitaxy and the development of novel optoelectronic devices including lasers, detectors, solar cells, and modulators. He holds several international patents on silicon photonics and epitaxial materials and co-authored more than 300 papers, including Nature Photonics, Nature Materials, Nature Communications, Science Advances, Nano Today, Nano Letters, Light Science & Applications, and Optica etc.

Professor Sally Day joined Ïã¸ÛÁùºÏ²ÊÖÐÌØÍø as a Royal Society University Research Fellow and has worked on the applications of liquid crystal in many different systems, a proportion of which are relevant to this course. She has 25 years of experience in the physics and engineering of liquid crystal devices, including leading on research projects at Ïã¸ÛÁùºÏ²ÊÖÐÌØÍø in collaboration with many different industries, aiming to use the unique properties of liquid crystals to achieve modulation or tuning of optical properties of devices in various optical systems. These will be studied in the APD module.