Fundamentals of Optoelectronic Devices and Applied Optics
The fourth unit is the first one that is taken at the start of the second year of the part-time MSc in Microelectronics, Optoelectronics and Communications.
The aim of this unit is to cover the fundamental aspects related to optoelectronic devices in order to provide the background necessary for the units on Optical Communications and Organic Electronics and Nanotechnology for Optoelectronic Devices.
Here, we will describe the basic principles of semiconductor devices before introducing some of the different types of light sources and detectors that have been developed. Following this, we will then aim to build-up an understanding of the electromagnetic wave propagation based upon Maxwell’s equations and optical theory and the background that is required for the Optical Communications unit. The next couple of sections then deal with the underlying principles and phenomena of importance in the area of applied optics before the unit concludes with a look at the exotic field of metamaterials and plasmonics.
In this section, we will explain the differences between metals, semiconductors and insulators and how doping changes the electrical behaviour of semiconductors. You will learn how to solve Schrödinger's equation in 1D and explain the importance of the results in quantum wells and heterostructures. We will show how to derive expressions for, and describe the importance of, the density of states, the effective density of states and the effective mass and we will show how the density of states in 2D and 3D can be derived. The ambipolar transport equation will then be introduced and you will be shown how to solve this equation in semiconductor devices. In this section, you will also learn how to derive expressions for the built-in voltage, electric field and capacitance of a pn junction and understand how to draw the band diagram of semiconductor devices under different bias conditions.
- Materials: metals, insulators, semiconductors
- Quantum mechanics: Schrödinger's equation, quantum theory of solids, band structure, effective mass, density of states, Fermi-Dirac statistics
- Semiconductors: intrinsic and extrinsic semiconductors, carrier concentrations, Fermi level, drift and diffusion currents, generation and recombination of carriers, the continuity equation and ambipolar transport
- pn junction diodes: built-in potential, depletion region, forward and reverse bias, capacitance
After covering the fundamental principles of semiconductors, this unit will then begin by explaining how light is detected in semiconductor devices. The operation of a PV cell will be explained, including how the output is affected by material selection, the incident light and the origins of the maximum power point. We will also consider how the maximum available output voltage from PV cells can be increased. Some of the different types of solar energy concentrators will be considered and you will learn how to derive the theoretical limit of such concentrators. Conversely, we will also consider how light can be generated in semiconductor LEDs and laser devices.
- Photons in semiconductors: direct and indirect band-gap semiconductors, optical loss and gain mechanisms, optical confinement, quantum well structures, heterostructures, light emitting diodes, semiconductor lasers
- Detection, photodiodes, APD, types of photovoltaic cells and their characteristics, optical concentrators and other enhancements
- Connecting PV cells and arrays: grid-connected and standalone systems
- Solar building products
For this section, we will aim to provide an understanding of the propagation of electromagnetic wave and material dispersion. We will show how Maxwell’s equations can be used to derive the electromagnetic boundary conditions as well as solutions for plane wave propagation. An introduction to optical fibre transmission systems will be provided and we will cover some of the basic properties of single mode and multimode optical fibres. This section will also include information about antennas and the course will describe what is meant by the gain, effective aperture and radiation resistance of an antenna. Using a solution to Maxwell’s equations for a short dipole, you will be shown how to derive some of these important characteristics.
- Electromagnetism for communications: Introduction to integral forms of Maxwell's equations
- Material response to fields
- Boundary conditions, derived from Maxwell's equations
- Derivation of capacitance and inductance for simple geometries, e.g. co-axial cable
- Wireless transmission
- Maxwell's equations for a plane wave; free space impedance; reflection at a boundary; boundary conditions for E and H; current-carrying conductors in high-frequency fields, skin depth
- Antennas; gain, types, link budget, dipoles, radiation resistance. Noise; sources, noise figure and temperature, link budgets, figures of merit
In this part of the unit, we will cover some of the fundamental principles of applied optics relevant to optical engineering. This will start with a demonstration of the use of ray matrices and we consider the origins and validity of ray optics and show how these can be applied to relatively simple lens arrangements and systems. In this topic, you will be shown how to derive, from first principles, the laws of reflection and refraction along with the Fresnel amplitude coefficients for transmission and reflection for both the Transverse Electric and Transverse Magnetic polarisation states. Following this, we will introduce the mathematical tools required to describe the polarisation state of an electromagnetic wave and show how these can be used to determine the polarisation properties after propagating through commonly used optical components. Techniques for dealing with both polarised and partially-polarised light will be considered. The section will conclude with the subject of interference including multilayer and multi-beam interference and the design of anti-reflection coatings.
- Introduction: History of the subject, overview of topics covered
- Geometrical optics: Laws of reflection/refraction, ray matrices, lenses and lens systems
- Examples of computer aided lens and optical design
- Polarisation: Definition, Jones and Stokes parameters, Jones and Mueller matrices, Poincare sphere, wave-plates and other examples
- Fresnel reflection and refraction: Polarisation effects, Brewster angle, external and internal reflection
- Interference: Coherence, fringe visibility, interferometers, thin films
- Diffraction: Diffraction integrals, diffraction at apertures and gratings, diffractive and refractive optics
Following on from the previous section, we will continue with one of the key phenomena associated with the wave nature of light: Diffraction. Will consider the origins of the Fresnel-Kirchhoff scalar diffraction formula and examine the resulting diffraction patterns for relatively simple, but no less important, aperture functions and gratings. You will learn how to apply the Fresnel-Kirchhoff diffraction formula to certain scenarios such as the near and far-fields and be able to understand the role that Fourier transforms play in describing Fresnel and Fraunhofer diffraction.
- Fourier optics: Fourier optics treatment of Fresnel and Fraunhofer diffraction and the spatial frequency domain
- Lenses as Fourier transform elements: image formation in terms of Fourier optics, coherent and incoherent imaging
- Characterisation of imaging systems: use of pupil functions, point spread functions, coherent and optical transfer functions
- Resolution of imaging systems, the effects of de-focus and other aberrations, pupil plane filtering
Metamaterials is a relatively new subject. The term ‘metamaterial’ means that it is something with properties that go well beyond ordinary materials. A rather concise definition is ‘artificial media with unusual electromagnetic properties’ such as negative refraction. This unit serves as an introduction to this fascinating research field. Fundamental concepts will be introduced with an emphasis on physical principles and simple mathematical models. Applications will be illustrated with new devices and technologies.
- Fabrication and applications of negative refractive index materials
- Calculation of permittivity and permeability in metamaterials.
- Plasmonic excitations in metals
- Manipulation of electromagnetic waves on a sub-wavelength scale.
- Sub-wavelength imaging.
- The perfect lens
This programme is subject to change
You will be issued with a reading list before your residential week via the Virtual Learning Environment (VLE).
Accommodation is not included in the course fee but may be available at your college and at Rewley House.
Bed and breakfast accommodation at other University colleges can also be booked on the Oxford Rooms website.
The Radcliffe Science Library (RSL) www.bodleian.ox.ac.uk/science is the main science research library at the university. The library holds copies of all of your reading list items, and most of your engineering library research will be done using this library’s resources. The library is located less than 5 minutes away from the Engineering Science department, at the corner of Parks Road and South Parks Road.
The subject librarian responsible for Engineering Science is Alessandra Vetrugno (email@example.com), based at the RSL
The Department for Continuing Education is based at Rewley House in Wellington Square, only five minutes walk from the Department of Engineering Science (Thom Building).
In addition to supporting the various aspects of the course that involve online learning, the Department has facilities available to students during their attendance in Oxford. In particular, the Department has a Graduate Room - a study space dedicated to graduate students with lockers, printing facilities and refreshments. The Graduate Room is accessible from 8.00am to 10.00pm (24hrs for students using the Department’s overnight accommodation). The Continuing Education Library, also located at Rewley House, has quiet study space and a ‘Reading Room’.
In order to participate in the pre-course material, you will need access to the internet and a computer meeting our recommended minimum computer specification which can be found online at onlinesupport.conted.ox.ac.uk/TechnicalSupport/YourComputer.php
This unit can only be taken as part of the MSc in Microelectronics, Optoelectronics and Communications.
Each of the six taught units will typically follow the structure below:
- Online material and exercises using the Virtual Learning Environment (VLE). We would expect you to take 12 weeks to work through this material. We will expect you to read specific material online and be familiar with the necessary pre-requisites of the course before each residential week in Oxford.
- A residential week in Oxford during which you will attend classes, complete tutorial exercises, participate in tutorial classes, meet your personal tutor and, where necessary, complete practical assignments.
- Assignments, which are available online and which must be completed and submitted by the deadlines (see Key Dates).
This course is taught by members of the Engineering Science Faculty, who you will meet as lecturers, as tutors for classes, or as your dissertation supervisor. One member of faculty will be assigned to you as a ‘personal tutor’ at the start of the course. He or she will provide advice and guidance, and discuss your academic progress. Your personal tutor will meet with you at each of the residential weeks, and you can contact him or her by email.
Your course supervisor will write a formal report on your progress three times a year on the online Graduate Supervision System (http://www.admin.ox.ac.uk/gss/). You will be able to view that report and will be asked to reflect on your progress as well.
Virtual Learning Environment
This course uses a Virtual Learning Environment (VLE), which is a web-based application called WebLearn.
Access to the course VLE is via an internet browser using your University Single Sign-On account. When the course has started and you have activated your Single Sign-On, you will have access to the student forum, information about student support, course documents and examiner reports. If you are unable to access WebLearn, please email the course team with details of your Single Sign-On (firstname.lastname@example.org).
You will be given access to an 'Induction' VLE which houses supporting materials for the MSc on Microelectronics, Optoelectronics and Communication at the start of the academic year, and to separate sites for each unit as and when you are due to take them.
During the course you will also be required to submit work through our online Moodle Assignment Submission System.
There will be two assignments comprising a set of problems to solve (example sheets), which are not formally assessed, that will be provided during the residential week. The first two assignments will not contribute to your overall degree outcome. You will receive verbal feedback from the tutor on your work at the tutorial classes during the residential week and written feedback via the VLE.
At the end of the residential week, two further example sheets will be made available via the VLE that will accompany the material to be covered. Again, they will not contribute to your overall degree outcome, and written feedback will be provided.
Finally, there will be two written examination papers that will be provided towards the end of the 12 week course. These papers will be formally assessed with the outcome providing the mark for the completed unit. They will be distributed online and must be submitted for assessment online. You must gain a pass in both of these examinable assignments in order to pass the whole unit. If you fail one of the assignments but pass the other, the mark from the assignment that you passed will be carried forward (further information can be found in the Exam regulations and conventions). For the assignment you failed, you will be set a new assignment and must re-submit this.
Additional worked examples and problems will be provided via the VLE.
This unit can only be taken as part of the MSc in Microelectronics, Optoelectronics and Communications.
Terms and conditions
Terms and conditions for applicants and students on this course
Sources of funding
Information on financial support