Riccarton, Edinburgh-based Heriot-Watt University is heading a consortium of Scottish universities researching the relatively unknown field of components for opto-electronic information processing. Their activities were highlighted in September 1988 when the Science & Engineering Research Council invited tenders for opto-electronic research funds. The Council received five proposals and drew up a short list of two, the Scottish consortium and Southampton University. It subsequently decided to award the UKP10m funding to Southampton, which is researching opto-electronics and fibre-based, largely one-dimensional systems. The Council has since invited the Scots to resubmit their proposal, albeit on a smaller scale than the original UKP10m would have allowed. However, even if funding has been cut to approximately UKP1m, it at least forms a base from which to generate other contributions, especially from industry. Like other universities involved in opto-electronics, Heriot-Watt receives some financial assistance from the Link programme, a joint Science & Engineering Research Council and Department of Trade & Industry scheme, and the Physics department has recently increased staff numbers specifically to expand its opto-electronic expertise. The use of opto-electronics was first mooted in 1960 with the advent of laser technology, but it wasn’t until 20 years later that practical schemes came into being. The Department of Physics at Heriot-Watt has been a leader in the field since 1980, when it discovered an effect that led to the development of a non-linear switching device, called the optical bi-stable switch. This gradually increases the power of an optical beam on a device, and can radically change the transmission of a semiconductor from high to low and vice-versa. Opto-electronics can be used to facilitate connections within and between chips, thereby overcoming the problems of space and cross-talk when too many wires are compressed into a small space. The Scottish consortium is combining parallelism and two dimensional holograms to evolve a technology that is applicable to optical switching computing and image processing, and at its simplest level, can be used for the recognition of handwriting and facial images. Other consortium members include the Universities of Edinburgh, St Andrews, Glasgow, and Strathclyde, and each is developing individual components used in opto-electronic information processing. Heriot-Watt is making the logic planes used in optical circuits, and holographic elements to connect chips. St Andrews makes optical sources like diode lasers, and Strathclyde University’s contribution is electron beam technology, often used in oscilloscopes. Glasgow University is involved in the development of alternative logic plane devices. The modulators that put information on optical beams come from Edinburgh University. Unlike Heriot-Watt, Edinburgh’s opto-electronics team didn’t evolve until 1984, when a wave of rationalisation forced scientists of diverse disciplines to pool resources. The Electrical Engineering Department, which has top-class silicon fabrication facilities, is collaborating with the Physics department on development of opto-electronics by combining the more mature technologies of liquid crystal and silicon. They are developing two types of modulators. The first is for high-speed applications, and each pixel has memory that controls light in a layer of liquid crystal above the silicon plane. The second is a static device with no pixel memory. It produces images that have to be refreshed, and has applications in television. The dynamic modulator is currently being developed under a precursor to the Link scheme, with GEC, STC, and UMIST, the University of Manchester Institute of Science & Technology, involved in the project. – Janice McGinn
