Terahertz frequency sensing has a unique part to play in the detection and identification of materials and objects. This frequency range, corresponding to a wavelength of around 0.1 mm, can be used to identify materials from their molecular spectra and to produce images of concealed objects. Terahertz spectra of drugs of abuse and explosives presented by a number of the contributing authors show that the presence of these materials can be detected in envelopes, packages and through clothing.
The technology of terahertz detection has largely been developed around expensive and bulky femtosecond laser systems but, as described in this book, advances in semiconductor superlattice technology are leading to compact “electronic” sources such as the quantum cascade laser, two-terminal “Gunn” type oscillators and even a THz frequency amplifier. These advances towards electronic (as opposed to optical) THz systems mean that the technology will become portable and much less costly.
Terahertz remote sensing is also discussed with the possibility of detection over distances of up to 30m using existing technology or even through the use THz waves generated locally in the vicinity of a target using only air as the transducer.
This book contains contributions from world leaders in terahertz science and technology and is complemented by comments and assessments from industry and security experts.
Author(s): R.E. Miles, X.-C. Zhang, H. Eisele, A. Krotkus
Series: NATO Science for Peace and Security Series B: Physics and Biophysics
Edition: 1
Publisher: Springer
Year: 2007
Language: English
Pages: 365
City: Dordrecht
Contents......Page 6
Organising Committee......Page 9
Sponsors......Page 10
Preface......Page 11
Theme 1: Devices......Page 12
Terahertz Emission from Semiconductors Excited by Ultrafast Laser Pulses......Page 13
Terahertz Generation by Multiplication......Page 27
Towards Superlattice Terahertz Amplifiers and Lasers......Page 41
Tailoring the Emission of Terahertz Quantum Cascade Lasers......Page 51
Guided Propagation of Terahertz Pulses on Metal Wires......Page 65
Superlattice and Other Negative-Differential-Resistance Devices: Current Status......Page 79
Theme 2: Interactions with Materials......Page 99
Molecular and Organic Interactions......Page 100
Terahertz Beam Interactions with Amorphous Materials......Page 116
Development of Tagless Biosensors for Detecting the Presence of Pathogens......Page 132
Theme 3: Detection and Sensing......Page 144
Improvements to Electronic Techniques for Terahertz Spectroscopic Detection......Page 145
Terahertz Time-Domain Spectroscopy of Crystalline and Aqueous Systems......Page 154
Continuous-Wave Terahertz Photomixer Systems for Real-World Applications......Page 173
Theme 4: Systems for Security......Page 191
Systems Requirements for A Multi-Channel Terahertz Contraband Scanner......Page 192
Challenges to Terahertz Counter-Terrorism and Security-Related Applications......Page 210
Terahertz Detection of Illegal Objects......Page 230
Terahertz Rays to Detect Drugs of Abuse......Page 246
Terahertz Spectroscopy for Explosive, Pharmaceutical, and Biological Sensing Applications......Page 256
Terahertz Communications: A 2020 vision......Page 329
Theme 5: Overview......Page 343
Applied Terahertz Science: The Technology of the Future, and Always Will Be?......Page 344
List of speakers......Page 356
List of participants......Page 358
Group photograph......Page 359
C......Page 360
H......Page 361
N......Page 362
S......Page 363
T......Page 364
Z......Page 365
