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Department of Chemical Engineering and Biotechnology


Terahertz is an emerging research area that has flourished rapidly over the last decade. The field has drawn together experts of various disciplines including optics, optoelectronics, semiconductor physics, electronic engineering and chemistry. Terahertz radiation possesses a number of properties that makes it a promising radiation source for spectroscopy and imaging. For example, terahertz radiation is non-ionising and highly sensitive to water content. To date, there have been many attempts to build imaging systems using terahertz radiation for a wide range of potential applications including security screening and non-invasive testing of opaque objects. However, the majority of these systems encountered problems with the low power of terahertz source and as a result were only able to produce two-dimensional images of thin samples.

Figure 1
Figure 1: Polystyrene phantom in the shape a clown's head a) Front view, b) Top view, c) A hole with diameter of 10 mm was introduced into the sample invisible from the outside

Figure 2
Figure 2: Some views of the reconstructed 3D image a) The hole inside the phantom is revealed, b) The shape of the phantom is reconstructed, c) The top view shows the features of the nose and cheeks.

Further information:

In this project, we have constructed a novel three-dimensional imaging system that uses a terahertz quantum cascade laser. Terahertz quantum cascade laser was experimentally realised for the first time in 2002, providing a new powerful source to generate terahertz radiation. The imaging system used an experimental protocol and reconstruction algorithm similar to X-ray computed tomography. We have successfully obtained three-dimensional images of a variety of samples, revealing both the external features and especially internal structures that are invisible from the outside.

Three-dimensional imaging with a terahertz quantum cascade laser
K. Lien Nguyen, Michael L. Johns, Lynn F. Gladden, Christopher H. Worrall, Paul Alexander, Harvey E. Beere, Michael Pepper, David A. Ritchie, Jesse Alton and Stefano Barbieri, University of Cambridge, Edmund H. Linfield, University of Leeds
Optics Express Vol. 14, Issue 6 pp2123-2129, 2006

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A new world (dis)order for efficient semiconductors

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Scientists from our Optoelectronic Materials and Device Spectroscopy group investigating perovskite materials for next generation solar cells and flexible LEDs have discovered that they can be more efficient when their chemical compositions are less ordered, vastly simplifying production processes and lowering cost.

The topology of disordered 3D graphenes: Rosalind Franklin’s pre-DNA problem untangled

8 November 2019

Researchers from our Computational Modelling group have published a possible solution to why disordered carbon structures are reluctant to turn into graphite, a puzzle that perplexed Rosalind Franklin before her discovery of the structure of DNA.

September paper of the month: flexible production of micro and nanofluidic devices

22 October 2019

Researchers from our Laser Analytics group have developed a laser-based manufacturing process that can produce combined nanofluidic and microfluidic devices in a fast and scalable manner.