This unit deals with both optoelectronic systems and some key optoelectronic devices. The central element of many optoelectronic systems is the semiconductor-diode laser. In the first half of the unit, the theoretical basis of the operation, design and practical uses of such lasers is developed. Topics include bandtails, homojunction and heterojunction structures, and quantum-well lasers. The practical use of diode lasers is influenced by coupling and modulation, while specialised designs are appropriate for obtaining single-mode and single-frequency semiconductor laser operation as well as high power from arrays. The non-linear optical behaviour of semiconductor materials and LiNbO3 waveguide technology leads to further applications. In simple terms, optoelectronic systems involve sources, propagation of radiation, and detection or interaction of the radiation with a target.
In the second half of the unit, a range of optoelectronic systems will be described, including fibre communication systems, optical data storage, remote sensing, and systems for manufacturing industry. As needed, further information on components of these systems will be introduced; for example, non-linear optical properties of optical fibre lead to soliton propagation in optical fibres. In addition, issues that are relevant to overall system design such as detection and noise, packaging, materials and optomechanical design will be considered.
To broaden their background, students will individually research further optoelectronic systems for a technology profile and presentation in a student seminar to the class. The practical component of the unit is regarded as important and a modern, well-equipped laboratory offers experiments involving lasers, fibre systems, fibre gyroscopes, scanning tunnelling microscopy and computer modelling of laser behaviour.
