Although optical computers may now be a reality, it seems that the new technology is unlikely to replace electronics entirely. According to Professor Midwinter of University College London, optoelectronics research is instead becoming increasingly focussed on communications and switching applications – from fibre optic cabling through to the internal structure of microchips. The capacity and speed of optoelectronics make it an ideal means for simplifying switching and routing with optical networking a possIbility for perhaps 10 years time – a prospect that researchers from University College are currently co-researching with British Telecommunications Plc in Harlow. Meantime at Southampton University, which prides itself on having the largest optoelectronics research group in the UK with 100 scientists, its own fabrication facilities and 35 dark room labs, activities are focussed on a variety of optical fibre, laser and sensor devices. There is, for instance, the development of acousto-optics – a technique that controls electromagnetic radiation via the periodic changes in refractive index caused by a sound wave – for use in bulk optic and fibre devices.
Optical fibre sensors
Also, optical fibre sensors are being developed for a variety of applications including gas, pressure and strain sensing and water monitoring, while special planar waveguide lasers in glass, crystal and thin films are being researched as a potential medium for integrated optical circuits. Diode-pumped, solid state miniature lasers are another promising area of research since if sufficiently powered they are capable of driving non-linear optical devices, while the development of fibre lasers is being investigated as an alternative to laser diodes. There is also work on photorefraction – investigating the properties of certain fibre and structures – and spectroscopy, to help understand better the properties of doped silicate materials and substances like fluorides that are of major interest to developers of solid-state lasers. On the telecommunications side, research is being carried out into high bandwidths that require high repetition pulses – a rate of 200GHz has been achieved and into Erbium-doped fibre amplifiers, which are a key component for future optical networks. And, finally, work is continuing into the fabrication of fibres. The researchers at Southampton use variants of the Modified Chemical Vapour deposition technique that was developed mainly in-house to produce a number of different types of fibres such as polarising, helical core and twin core, along with a range of single and multimode silica fibres for telecommunications, sensing and medical applications. The University also says that it can supply state-of-the art fibre to other universities and industry across the world in accordance with specific designs, if required. – Lynn Stratton
