LEOS
Profile
LEOS
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John Marsh |
John Marsh is one of the newly elected members of the Board of Governors and will serve from 2001 to 2003. Since 1999 he has also held the position of Vice-President, Membership & Regional Activities - Europe, Mid- East, Africa, a position he continues to hold in 2001.
John was born in Edinburgh, Scotland in 1956, was brought up in Glasgow and studied for a B.A. in Electrical Sciences at Churchill College, Cambridge. This gave him an interest in electronic and optoelectronic devices that continues to the present day. After leaving Cambridge he received an M.Eng. from the University of Liverpool then, in 1978, moved to the University of Sheffield to study for a Ph.D. His thesis was concerned with electron transport in the alloy semiconductor InGaAsP grown on InP. At the time certain compositions of this alloy were predicted to be ideal for microwave devices, but in reality the large degree of alloy scattering limited the mobility and the peak velocity of electrons. The research project included growing epitaxial material, fabricating devices and measuring the first complete velocity-field characteristics across the alloy composition range. In addition refinements to the model of alloy scattering were developed, which ascribed alloy scattering to potential variations arising from compositional clusters rather than from the central cell potential. It was demonstrated that, for alloys lattice-matched to InP, the ternary alloy In0.53Ga0.47As was the optimum material for microwave applications.
John remained at Sheffield, as a post-doc then University Research Scientist, until 1986 when he joined the Department of Electronics and Electrical Engineering at the University of Glasgow. Starting as a Lecturer, he was promoted to Senior Lecturer (1990), Reader (1994) and Professor of Optoelectronic Systems (1996), the position he currently holds. Collaboration is a key aspect of his work and he has formal and informal interactions with many institutions worldwide. In 1999 he spent six weeks as a Visiting Professor in the City University of Hong Kong.
At Glasgow he has built a substantial group of outstanding graduate students and post-docs whose research is focused almost entirely on semiconductor integrated optics. Significant advances in photonic integrated circuit processing using quantum well intermixing (QWI) as an integration technology have been made. These include the development of a range of different QWI processes, such as ion induced, dielectric cap induced and laser induced QWI; studies of material properties, for example the refractive index changes accompanying intermixing; demonstration of key components such as low-loss optical waveguides and bandgap tuned gain sections. His group has also made novel use of QWI as a sensitive probe for detecting point defects introduced by dry-etching and for improving understanding of the physics and chemistry of dry-etching. Integrated devices made by the group include extended cavity mode-locked semiconductor lasers for carrying out all-optical clock extraction in high data rate communication systems, new approaches for improving the mode quality of high-power semiconductor lasers, and integrated crosspoint switches. QWI has also been applied to nonlinear optical waveguides to realize quasi-phase matching. Recently the group has reported advances in lasers for use in microwave optics. These include electrically locked sources at up to 56 GHz and lasers mode-locked at frequencies up to 2.1 THz, the highest repetition frequency ever reported.
He has been active in the IEEE, in various capacities, since 1993. In 1996 Alan Miller and he founded the Scottish Chapter of LEOS and John became its first Chair. The Chapter won the 1997,1998 and 2000 LEOS Chapter-of-the-Year awards and the 1999 award for Most Innovative Chapter. As well as having a strong lecture programme, the Chapter has established an ‘Entrepreneurship Club’ in collaboration with Scottish Enterprise. John is also an elected member of the Council of the Scottish Optoelectronics Association and is a Fellow of the IEE, IEEE, Royal Society of Arts and Royal Society of Edinburgh.
In the last few years John has become increasingly interested in commercialising research. In the period 1997 to 1998 he helped to establish Compound Semiconductor Technologies Ltd, an innovative III-V opto-foundry jointly owned by Scottish Enterprise, Scottish Enterprise Glasgow, and the Universities of Glasgow and Strathclyde. Part of the company’s remit is to provide a commercial outlet for IP developed by the Universities, and it has appropriate incubation and laboratory space in addition to its clean room facilities. He was a Director of the company from January 1999 until July 2000.
Last year he formed Intense Photonics Ltd. with Dr. Craig Hamilton. The company was set up to supply next-generation monolithic photonic integrated circuits to the optical networking industry, and is currently developing a range of innovative integrated products in both GaAs and InP based materials. These include 980 nm lasers and high-functionality signal wavelength sub-systems. John is currently Intense’s Chief Research Officer and a member of its Board of Directors.
On the personal side, he met his wife, Anabel, in Sheffield during his Ph.D. studies. They have joint interests in hill walking, attending concerts and travel. In the last few years their summer vacations have included visits to the Galapagos Islands, mainland Ecuador, Nepal and Tibet. The LEOS Annual Meeting in Puerto Rico was John’s second trip to the Caribbean and future holidays there are a high priority. He also enjoys cooking and less virtuous pursuits such as good eating and drinking.