Millimetre wave and related devices
The
millimetre wave group specialises in developing instruments
for applications involving electromagnetic radiation of
wavelength 1 to 4mm (frequency 70-300 GHz). These wavelengths
lie between the visible and microwaves, and have only
recently started to become exploited. The group has developed
new sources, detectors, and quasi-optical components for
a range of systems used for remote sensing, radar and
signal processing. Our pictures show the use of plastic
lenses and wire-grid polarisers in this technology. At
these wavelengths, any hot object radiates significantly
and this has been exploited for imaging and for systems
for protection from friendly-fire in battlefield
situations.
Another project using mm-waves is attempting to create an early-warning system for volcanic eruptions, illustrated in action below. More information on the background to this project is available on the University's news page.
The use of these high frequencies is also allowing spectacular advances in electron-spin-resonance spectroscopy. In these techniques the mm-waves interact with electrons in a sample to allow probing of samples of biological, chemical and physical interest. Work is also in progress on microwave-triggered switches and electron sources.
BDS 27.7.05
