Leeds’ Terahertz Technology Research Earns European Grant

Research into terahertz technology at the University of Leeds has received a €2.5 million European grant, the university announced on 20 January. The Advanced Investigator Grant from the European Research Council is in recognition of the outstanding work conducted by Professor of Terahertz Electronics, Edmund Linfield. It is one of only 105 projects selected across Europe out of 736 applicants in physical sciences and engineering. Although terahertz technology is currently confined to quite narrow applications, it has far-reaching potential in medicine and industrial process monitoring, among other sectors, according to Linfield.

“The potential uses for terahertz technology are wide-ranging, but are currently limited to niche applications in fields such as pharmaceutical analysis and astronomy,” says Linfield. This is because most systems on the market are expensive and physically large, he explains. Linfield intends to use the funding to study both the fundamental science and potential applications of terahertz quantum cascade lasers. Quantum cascade lasers are small, and potentially portable, sources of radiation in the terahertz frequency range of the electromagnetic spectrum. “The availability of cheap, compact systems would open up a wide range of opportunities,” says Linfield, who is Director of the Institute of Microwaves and Photonics, one of two research institutes within the School of Electronic and Electrical Engineering.

The prestigious Advanced Investigator Grant award scheme is aimed at supporting established research leaders in carrying out pioneering work in their field. Linfield’s grant, one of two made to the university this year, follows an award in 2009 to Professor Giles Davies, also from the School of Electronic & Electrical Engineering.

The school has one of the world’s leading research groups in terahertz technology and one of the largest university facilities for terahertz research internationally. It is also one of a very small number of laboratories in the world to grow terahertz quantum cascade lasers, using a technique known as molecular beam epitaxy (MBE). The School’s MBE system (costing around £1M), and Linfield’s team’s expertise in using it, will underpin the research funded through this European grant.

Molecular beam epitaxy (MBE) is a technique that allows single crystals to be grown by individual atomic monolayers. The Advanced Investigator Grant will use MBE to grow layers of the semiconductors GaAs and AlGaAs (doped with Si) at a typical rate of one atomic layer per second. To achieve this, the constituent atoms (e.g. Ga, Al) are evaporated from heated furnaces and land on a hot, rotating, substrate. Shutters are used to block the furnace from the substrate when a specific material is not required. To avoid any contamination of the growing material, ultra-high vacuum conditions are used with typical background pressures of 10-11 mbar. Terahertz quantum cascade lasers are typically made up of more than 1000 individual GaAs/AlGaAs layers, the thickness of each being controlled to atomic monolayer accuracy by MBE.

Tags: Leeds, research grant, Terahertz