A World Leading Research Programme Opening up the Terahertz Spectrum
The terahertz (THz) frequency region within the electromagnetic spectrum, covers a frequency range of about one hundred times that currently occupied by all radio, television, cellular radio, Wi-Fi, radar and other users and has proven and potential applications ranging from molecular spectroscopy through to communications, high resolution imaging (e.g. in the medical and pharmaceutical sectors) and security screening. Yet, the underpinning technology for the generation and detection of radiation in this spectral range remains severely limited, being based principally on Ti:sapphire (femtosecond) pulsed laser and photoconductive detector technology, the THz equivalent of the spark transmitter and coherer receiver for radio signals. The THz frequency range therefore does not benefit from the coherent techniques routinely used at microwave/optical frequencies. Now an EPSRC Programme grant awarded to leading Terahertz researchers at UCL, Cambridge and Leeds universities and the London Centre for Nanotechnology will address this.
We have recently demonstrated optical communications technology-based techniques for the generation of high spectral purity continuous wave THz signals at UCL, together with state-of-the-art THz quantum cascade laser (QCL) technology at Cambridge/Leeds. We will bring together these internationally-leading researchers to create coherent systems across the entire THz spectrum. These will be exploited both for fundamental science (e.g. the study of nanostructured and mesoscopic electron systems) and for applications including short-range high-data-rate wireless communications, information processing, materials detection and high resolution imaging in three dimensions.
"This programme will enable us to address the THz spectrum with the same precision and sensitivity as is today possible at radio frequencies, leading to this underused part of the electromagnetic spectrum finally achieving its full scientific and commercial potential." Professor Alwyn Seeds, Principal Investigator for Programme and Head of UCL Electronic and Electrical Engineering
Our vision is to open up the THz spectrum for widespread scientific and commercial application, through the use of photonics-enabled coherent techniques. This will be achieved by bringing together optical communications technology-based techniques, for the generation of high spectral purity continuous wave (CW) THz frequency signals, with state of-the-art THz quantum cascade laser (QCL) technology.
We will create new, compact, low (few Watts) power consumption semiconductor-based coherent device and systems technologies, able to span the entire THz spectrum of applications interest. The successful completion of this Programme will bring capabilities available at radio or optical frequencies to this traditionally difficult part of the electromagnetic spectrum. However, our vision goes much further. The availability of THz radiation, albeit in the form of various expensive accelerator and pulsed higher frequency laser sources, has already spurred a large and growing awareness of what is possible using THz probes for cutting edge fundamental science. Building on this momentum, we will study how the new technology will advance the state-of-the-art in measuring and controlling magnetic and vibrational states in systems of biomedical, chemical and physical interest. As this Programme goes well beyond what could be achieved by the current technology, it will lead to significant impact including advances in scientific capability through the availability of compact, precise and highly sensitive THz spectroscopy tools.
The THz frequency region is the last unexploited part of the electromagnetic spectrum. Now we hope to change that. Our ambition for this Programme is that it will lead to this historically underused part of the electromagnetic spectrum finally achieving its full scientific and commercial potential. We will work with many commercial partners to achieve this.