Department of Physics, Unit Catalogue 2007/08 |
PH20061 Electromagnetism 1 [WL] |
| Credits: 6 |
| Level: Intermediate |
| Semester: 2 |
| Assessment: EX 85%, PR 15% |
| Requisites: |
| Before taking this unit you must take PH10051 and take PH10053 and take PH20019 |
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Aims: The aims of this unit are to develop a vectorial description of electric, magnetic and electromagnetic fields in infinite materials and at boundaries between materials, to derive some individual solutions and to make use of them in a few important applications. A further aim is to provide an introduction to the operation of lasers.
Learning Outcomes: After taking this unit the student should be able to: * derive and interpret Maxwell's equations and their solution in vacuum; * list the distinguishing features of electromagnetic plane waves and write down a mathematical expression for a linearly or circularly polarised light wave; * analyse in detail the propagation of vectorial plane waves in vacuum and in various materials; * describe the origins of polarisation and magnetisation in materials; * match electric and magnetic fields at boundaries between materials and explain the origins of Brewster's angle and total internal reflection; * describe how lasing action is obtained and maintained and outline the main properties of laser light; * conduct short experiments on various topics, record details of experimental method and results to an appropriate standard, and write a scientific report displaying an appropriate standard of presentation, style, structure, attention to detail and analysis. Skills: Written Communication T/F A, Numeracy T/F A, Data Acquisition, Handling, and Analysis T/F A, Information Technology T/F A, Problem Solving T/F A, Working as part of a group T/F, Practical laboratory skills T/F A. Content: Introduction to Maxwell's equations (7 hours): Derivation of integral and differential forms of Maxwell's equations and continuity equation. The wave equation in source-free vacuum. Plane wave solutions. Electromagnetic plane waves (3 hours): 3D plane waves, vector nature of electromagnetic waves; relationships between E, B and k. Impedance. Electromagnetic energy and the Poynting vector. Radiation pressure. Polarisation; Law of Malus, circular and elliptical polarisation. Birefringence, wave plates. Maxwell's equations in infinite materials (6 hours): Concepts of linearity, isotropy and homogeneity. Characterisation of materials in terms of macroscopic parameters. Dipoles, susceptibility and polarisation / magnetisation. The modified wave equation; solution in conductors, dielectrics, lossy media and plasmas. Boundaries between media (4 hours): The general electromagnetic boundary conditions. Plane waves at a planar boundary, general angle of incidence (Fresnel equations). Total internal reflection and evanescent waves. Coefficients of transmission and reflection. Brewster and critical angles. Lasers (2 hours): Interaction between light and matter. The Einstein relations. Obtaining and maintaining lasing action. Cavity modes. The properties of laser light. Laboratory: Performance of experiments designed further to develop practical skills and support lecture material. |