John Carroll is a Professor in the Department of Engineering and Head of the Electrical Division at Cambridge University. He joined the university as a Lecturer and Fellow of Queen's College in 1967, forming a research group studying Gunn and Trapatt microwave devices. He has authored three books on semiconductor devices but for the last ten years the emphasis of his work and publications has been the design and modelling of laser diodes. He is currently Chairman of the Council of the School of Technology and a member of the university's General Board. James Whiteaway graduated from Queen's College, Cambridge, in 1973 and joined Standard Telecommunications Laboratories (now Nortel) at Harlow, UK, to work on laser diodes. He gained his PhD from Cambridge University in 1983 for his published work on semiconductor lasers. He is now the External Research Co-ordinator for the Nortel Optical Communications Programme Unit and leads a team researching optical device modelling. He has accomplished pioneering work on phase-shifted DFBs which have set the industry standards for performance of distributed feedback laser devices. Dick Plumb graduated from Christ's College, Cambridge, in 1973 after holding a commission in the Royal Navy. Having gained his PhD on high-speed photodiodes, he joined the Standard Telecommunication Laboratories in 1977. Later he worked for BT and D Technologies Ltd. on laser diode technology materials, and took a leading role in a number of European programmes introducing DFB lasers into optical communication systems. He currently leads research into high-power and tunable laser diodes at the Department of Engineering, Cambridge University, which he joined as a lecturer and Fellow of Peterhouse in 1991.