Terahertz Frequency Detection And Identification Of Materials And Objects

Terahertz frequency sensing has a unique part to play in the detection andidentification of materials and objects. This frequency range corresponding toa wavele... » 

Terahertz frequency sensing has a unique part to play in the detection andidentification of materials and objects. This frequency range corresponding toa wavelength of around 0.1 mm can be used to identify materials from theirmolecular spectra and to produce images of concealed objects. Terahertz spectraof drugs of abuse and explosives presented by a number of the contributingauthors show that the presence of these materials can be detected in envelopespackages and through clothing. The technology of terahertz detection haslargely been developed around expensive and bulky femtosecond laser systemsbut as described in this book advances in semiconductor superlatticetechnology are leading to compact electronic sources such as the quantumcascade laser twoterminal Gunn type oscillators and even a THz frequencyamplifier. These advances towards electronic as opposed to optical THzsystems mean that the technology will become portable and much less costly.Terahertz remote sensing is also discussed with the possibility of detectionover distances of up to 30m using existing technology or even through the useTHz waves generated locally in the vicinity of a target using only air as thetransducer. This book contains contributions from world leaders in terahertzscience and technology and is complemented by comments and assessments fromindustry and security experts. «