Over the past three decades a new spectroscopic technique with unique possibilities has
emerged. Based on coherent and time‐resolved detection of the electric field of ultrashort …

We review pioneering and recent studies of the conductivity of solid state systems at
terahertz frequencies. A variety of theoretical formalisms that describe the terahertz …

The non-equilibrium control of emergent phenomena in solids is an important research
frontier, encompassing effects such as the optical enhancement of superconductivity …

The terahertz region lies between the microwave and infrared regions of the electromagnetic
spectrum such that it is strongly attenuated by water and very sensitive to water content …

We review the development of terahertz (THz) technology and describe a typical system
used in biomedical applications. By considering where the THz regime lies in the …

Collective excitations of bound electron-hole pairs—known as excitons—are ubiquitous in
condensed matter, emerging in systems as diverse as band semiconductors, molecular …

Chemical and physical systems undergoing change display spectral signatures from the
radio frequency to the X-ray region of the electromagnetic spectrum. This has led to the …

Terahertz spectroscopy emerged about 13 years ago with the demonstration that nearly
single-cycle pulses of far-infrared radiation could be generated, propagated through free …

Terahertz time-domain spectroscopy is used to study properties of nonpolar amorphous
materials. Terahertz absorption spectra and refractive indices were measured in a number of …

In this paper techniques for the generation and measurement of ultrashort pulses in the
frequency range from about 0.1 to 10 THz are reviewed. The methods for generation are …