Want an overview of where the technology of terahertz detection has been going? Here it is. The technology 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.

Comprehensive discussion on terahertz sensing for security purposes

Devices.- Terahertz Emission from Semiconductors Excited by Ultrafast Laser Pulses.- Terahertz Generation by Multiplication.- Towards Superlattice Terahertz Amplifiers and Lasers.- Tailoring the Emission of Terahertz Quantum Cascade Lasers.- Guided Propagation of Terahertz Pulses on Metal Wires.- Superlattice and Other Negative-Differential-Resistance Devices: Current Status.- Interactions with Materials.- Molecular and Organic Interactions.- Terahertz Beam Interactions with Amorphous Materials.- Development of Tagless Biosensors for Detecting the Presence of Pathogens.- Detection and Sensing.- Improvements to Electronic Techniques for Terahertz Spectroscopic Detection.- Terahertz Time-Domain Spectroscopy of Crystalline and Aqueous Systems.- Continuous-Wave Terahertz Photomixer Systems for Real-World Applications.- Systems for Security.- Systems Requirements for A Multi-Channel Terahertz Contraband Scanner.- Challenges to Terahertz Counter-Terrorism and Security-Related Applications.- Terahertz Detection of Illegal Objects.- Terahertz Rays to Detect Drugs of Abuse.- Terahertz Spectroscopy for Explosive, Pharmaceutical, and Biological Sensing Applications.- Terahertz Communications: A 2020 vision.- Overview.- Applied Terahertz Science: The Technology of the Future, and Always Will Be?.