Bulletin Number One 1982

International Summer School on Optoelectronics I f agriculture marks a watershed in the history o f mankind and industrialization heralds the advent o f a second era, then information is surely a crucial element in the "Th ird Wave" o f human civilization. Efficient transmission o f information becomes a challenge. Telephones come to mind, but so do the road excavations for laying telephone lines - conventional lines are not particularly efficient, typically carrying only a few conversations at a time, so that a large number o f lines would be needed. Information-carrying capacity depends on the number o f ups and downs in the signal amplitude every second; these may be thought o f as the dots and dashes in the Morse code, or the O's and I 's uttered by a computer. Ordinary radio signals vibrate at some 500,000 to 100,000,000 times a second. Microwaves (such as those in a kitchen oven) manage some 2,500,000,000 oscillations a second, and until recently that was the best that one could do for transmitting information. Light is also a kind o f oscillation, but incredibly rapid, at some 30,000,000,000,000 times a second; the problem is to harness this oscillation and wed it to electronic circuitry. That is the science o f optoelectronics, which is the theme o f the Inter national Summer School organized by the University for two weeks at the end o f July. In rapidly advancing disciplines, books become rapidly outdated. Journal articles, being the work o f a single person or group, can only be individual pieces o f the jigsaw. A Summer School, in which experts give lectures on the subject, is therefore a favoured format for learning about recent developments. The lectures were directed by Dr. P.K. Tien, head o f the Electron Physics Research Department at Bell Laboratories. The other lecturers were Dr. Charles Kao, Vice-President o f ITT, and previously Professor o f Electronics at CUHK; Professor E.P. Ippen o f M IT and Dr. M. Nakamura o f Hitachi Central Laboratory. The Hong Kong Telephone Co., which has already installed an optical network, provided actual demonstrations. The participants, numbering about fifty , were mostly postdoctoral scientists from Hong Kong (including staff o f the Electronics and Physics De partments), from various countries in Asia, as well as from Europe and America. The participants also presented papers on their own research. The lectures were centred round four main areas. (1) A discussion on the trends and overall development in optical communication systems, including the material aspects, system design and economic considerations. (2) Basic physical principles involved in the design o f integrated optical systems. (3) Ultrashort light pulses lasting under 1/ ,000,000,000,000 second. Such short pulses would be useful in optical communication systems, have their own scientific interest, and provide a tool for probing rapid molecular motion. (4) The principles and fabrication techniques o f semiconductor lasers, which are ideal light sources for optical communication. Apart from benefiting staff and students, the Summer School was intended to be a modest contri bution to the transfer o f technology to the developing regions o f Asia. As such, it received generous support from the Croucher Foundation, as well as from IBM, UNESCO, Committee on Science and Technology in Developing Countries, and Cathay Pacific Airways. —K. Young 17