The terahertz (THz) frequency region of the electromagnetic spectrum spans the frequency range between the mid-infrared and the millimetre/microwave (300GHz–30THz). In the past decade or so, THz science and technology has advanced considerably, with both optical bench-based systems and solid state THz lasers (quantum cascade lasers, QCLs) now routinely available.
We are international leaders in this field of research and work with researchers worldwide, regularly receiving visitors from abroad who wish to work in our laboratories.
Our state-of-the-art facility accommodates:
• Eight optical bench systems in a positive-pressure, temperature-controlled environment
• Five femtosecond pulsed imaging and spectroscopy systems (and an OPO), including ultra-broadband capability (>20THz), pump-probe techniques and both free-space and guided-wave arrangements
• Bruker 66v Fourier transform infrared spectrometer for characterisation of QCL devices
• QCL-based imaging and spectroscopy systems, in both transmission and reflection geometries (specular and diffuse)
• 8mK cryogen-free dilution refrigerator, with fibre-optic and microwave access, several 1.2K optical access cryostats, including cryogen-free systems, and magnetic fields up to 12T, for low-temperature nanostructure measurements and for operation of QCLs
This laboratory is complemented by a III–V molecular beam epitaxy growth system, wide-ranging semiconductor processing facilities and our extensive microwave engineering laboratories.
Our researchers are involved in the development of new THz systems and the use of THz techniques in a broad spectrum of imaging and analysis applications:
• THz QCL hardware – design, growth, fabrication and measurement
• THz QCL imaging and spectroscopy
• THz techniques to study low-dimensional semiconductor structures, nanostructures and other condensed matter systems
• On-chip, guided-wave, THz filter systems – eg to investigate biological systems such as DNA and proteins
• Broadband THz systems – understanding the fundamental interactions of THz radiation with a range of materials, including those of security interest, such as illegal drugs and explosives