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The analysis revealed the image of an upturned face underneath the fresco © Bianca Jackson and Dominique Martos-LevifA collaboration between analytical scientists and the Louvre in France has revealed a hidden work under one of the museum’s frescoes. The research is an example of the broadening field of terahertz spectroscopy, using wavelengths of electromagnetic radiation between microwave and infrared.The fresco, Trois hommes armes de lances, is part of the Louvre’s Campana collection – pieces that once belonged to Giampietro Campana, an excavator and collector of ancient artifacts in the 19th century. Campana was known to restore the pieces he obtained...

Researchers in the US have used an artificially-structured "metamaterial" to build a device that can control highly-elusive terahertz (THz) radiation. The modulator is claimed to be ten-times better at switching a THz beam than previous designs and could pave the way for the use of the radiation in a wide range of applications in chemistry, astronomy and even airport security (Nature 444 597). Sandwiched between the microwave and infrared regions of the electromagnetic spectrum (at about 300 GHz to 10 THz), THz radiation is notoriously difficult to work with. It is too high frequency to be manipulated electrically like microwaves...

A breakthrough in the harnessing of ‘T-rays’ - electromagnetic terahertz waves - which could dramatically improve the detecting and sensing of objects as varied as biological cell abnormalities and explosives has been announced. Researchers at the University of Bath, UK, and in Spain have said they have found a way to control the flow of terahertz radiation down a metal wire. Their findings are set out in a letter published in the current journal Physical Review Letters. The title of the letter is: “Terahertz surface plasmon polariton propagation and focusing on periodically corrugated metal wires”. Terahertz radiation, whose frequency is...

Researchers in Europe have made advances with a new technology that could one day be used to detect explosives or biological weapons in parcels, locate cancers beneath the skin, reveal the state of wounds beneath dressings and see through fog. As part of an effort sponsored by the European Space Agency, which works to bring the continent up to speed in outer-space research by coordinating multinational projects, scientists were able to take the first "photographs" using terahertz radiation. Researchers with the StarTiger project released on Tuesday images of a human hand taken through a 15 millimeter stack of paper, as...