"This book presents the current state of knowledge in the field of terahertz spectroscopy, providing a comprehensive source of information for beginners and experienced researchers alike whose interests lie in this area. The book aims to explain the fundamental physics that underpins terahertz  technology and to describe its key applications. Highlights of scientific research in the field of terahertz science are also outlined in some chapters, providing an overview as well as giving an insight into future directions for research.

Transmission, reflection, refraction and scattering of Terahertz radiation.- Optical constants and dispersion relations in THz spectroscopy.- Scattering effects.- Converging Terahertz beam vs. plane wave.- Signal Processing - Wavelet Transform.- Signal Processing - Fractional Fourier transformation and spectrogram in signal processing of Terahertz pulses.- Terahertz Spectroscopy.- Crystalline and non-crystalline solids.- Liquids and Biomolecules.- Ellipsometry and active polarization control of Terahertz waves.- ATR sensing at terahertz frequencies.- Pump-probe spectroscopy.- Liquid crystals.- Waveguide spectroscopy.- Condensed matter physics.- Assignment of vibrational modes in crystalline materials.- On-chip pulsed Terahertz spectroscopy.- Nonlinear terahertz spectroscopy.- Terahertz Imaging.- Far-field / Near-field.- Biomedical Imaging.- Pharmaceutical imaging.- Terahertz tomography.- Security.- Artists' materials characterization.- Interesting Physics at Terahertz Frequencies.- Plasmonic structures.