As a bridge between electronics and photonics, terahertz science and technology has made tremendous progress in the past decades. While terahertz wave generation from gas, solid and plasma with femtosecond laser excitation has been widely used, terahertz liquid photonics is a newly emerging topic in recent years. This book includes the most recent experimental results, theoretical analysis, and simulated calculations on terahertz emission and detection from liquid materials under ultrashort-pulse laser excitation, providing readers a comprehensive understanding of current developments in terahertz liquid photonics. By comparing with traditional sources, distinctive properties of terahertz wave generation from liquids are discussed in detail, which provides a new perspective in exploring laser-matter interactions.

This book presents the state-of-the-art of Terahertz spectroscopy. It is a modern source for a beginners and researcher interested in THz spectroscopy. The basics and physical background of THz spectroscopy and technology are explained, and important applications are described. The book presents the highlights of scientific research in the field of THz science and provides an excellent overview of the field and future directions of research. Over the last decade the field of terahertz spectroscopy has developed into one of the most rapidly growing fields of spectroscopy with large impact across a wide range of scientific disciplines. Due to substantial advances in femtosecond laser technology, terahertz time-domain spectroscopy (THz-TDS) has established itself as the dominant spectroscopic technique for experimental scientists interested in measurements in this frequency range. In solids and liquids terahertz radiation is at resonance with both phonon modes and hydrogen bonding modes which makes it an ideal tool to study the interaction between molecules in a unique way, thus opening a wealth of opportunities for research in physics, chemistry, biology, materials science and pharmaceuticals. This book provides an easy access to scientists, engineers and students alike who want to understand the theory and applications of modern terahertz spectroscopy.

During the past several decades, tremendous progress has been made in terahertz (THz) science and technology. There is a continuing need to have terahertz waves ready for practical applications. Terahertz photonic and electronic devices are being readied to be employed in application systems such as communication links, satellite communications, radar, surveillance, hard/soft material heating, biomedical treatment, and biomedical diagnostics. This book focuses on the advances in terahertz source technologies both from photonics and electronics (solid-state and vacuum-state) points of view. Written in a noncomplicated language, the book will be useful for a broad spectrum of readers, including advanced undergraduate- and graduate-level students in electronics and photonics, researchers in various disciplines in physics, chemistry, biology, astronomy, and electrical engineering, system engineers in various industrial sectors, general readers, and those who are interested in the interaction between electromagnetic waves and matters and in the effects of electromagnetic waves on matters.

Terahertz (THz) radiation, which is electromagnetic radiation in a frequency int- val from 0.3 to 10 THz (1 mm–30 ?m wavelength), is the next frontier in science and technology. This band occupies a large portion of the electromagnetic sp- trum between the infrared and microwave bands. Basic research, new initiatives, and developments in advanced sensing and imaging technology with regard to the THz band remain unexplored compared to the relatively well-developed science and technology in the microwave and optical frequencies. Historically, THz technologies were used mainly within the astronomy c- munity for studying the background of cosmic far-infrared radiation, and by the laser-fusion community for the diagnostics of plasmas. Since the ?rst demonstration of THz wave time-domain spectroscopy in the late 1980s, there has been a series of signi?cant advances (particularly in recent years) as more intense THz sources and higher sensitivity detectors provide new opportunities for understanding the basic science in the THz frequency range.

Electromagnetic waves within a terahertz frequency range are becoming critical to investigating molecules, materials, and possible applications that are operated by both visible light and infrared rays. This book discusses sensing, imaging, and optoelectronic technologies of terahertz electromagnetic waves in theory and experiments. Most terahertz technologies can be explained by fundamentals of applied physics that have been demonstrated in other spectral ranges. However, the optoelectronic technology and corresponding configurations of imaging and sensing techniques are so special for various terahertz material polarization waves, which are excited in solid-state media by high-peak power lasers and waveguide transportation. Thus, this book also specifies terahertz parameters and available technologies.

This book is aimed to bring the emerging application aspects of THz technology and various modules used for its successful realization. It gathers scientific technological novelties and advancements already developed or under development in the academic and research communities. This book focuses on recent advances, different research issues in terahertz technology and would also seek out theoretical, methodological, well-established and validated empirical work dealing with these different topics. In particular, this textbook covers design considerations and current trends of THz antennas and antenna arrays to deal with the transmission and reception of THz EM waves. It also presents a discussion on metamaterial structures, meta-surfaces, and absorbers to be used for some kind of sensing and detection applications. Furthermore, it reports on THz wireless communication aspects, 6G network issues and challenges, advantages and disadvantages, generation and detection of THz waves, Signal and Communication Processing for THz communication, reconfigurable low-noise amplifier (LNA) design, III-Nitride HEMTs for THz Applications, photonic crystal fiber for sensing applications, THz Design Variable Estimation by Deep Optimization, and THz Imaging issues. Once the readers finish studying this book then they will learn about the importance of THz technology, advancement in the field, applications, THz modules like antennas, MIMO and DRAs, communication aspects, LNAs, generation of THz waves, etc and future scope. It also leads to enhancement in their knowledge in THz technology, gives a platform to future technology and novel applications realization.

This new edition features numerous updates and additions. Especially 4 new chapters on Fiber Optics, Integrated Optics, Frequency Combs and Interferometry reflect the changes since the first edition. In addition, major complete updates for the chapters: Optical Materials and Their Properties, Optical Detectors, Nanooptics, and Optics far Beyond the Diffraction Limit. Features Contains over 1000 two-color illustrations. Includes over 120 comprehensive tables with properties of optical materials and light sources. Emphasizes physical concepts over extensive mathematical derivations. Chapters with summaries, detailed index Delivers a wealth of up-to-date references.