Download or read book Broadband Terahertz Photonics written by David Patrick Burghoff and published by . This book was released on 2014 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, quantum cascade lasers have emerged as mature semiconductor sources of light in the terahertz range, the frequency range spanning 1 to 10 THz. Though technological development has pushed their operating temperatures up to 200 Kelvin and their power levels up to Watt-level, they have remained unsuitable for many applications as a result of their narrow spectral coverage. In particular, spectroscopic and tomographic applications require sources that are both powerful and broadband. Having said that, there is no fundamental reason why quantum cascade lasers should be restricted to narrowband outputs. In fact, they possess gain spectra that are intrinsically broad, and beyond that can even be tailored to cover an octave-spanning range. This thesis explores the development of broadband sources of terahertz radiation based on quantum cascade lasers (QCLs). The chief way this is done is through the development of compact frequency combs based on THz QCLs, which are able to continuously generate milliwatt levels of terahertz power covering a fractional bandwidth of 14% of their center frequency. These devices operate on principles similar to microresonator-based frequency combs, and make use of the quantum cascade laser's fundamentally large nonlinearity to phase-lock the cavity modes. These devices will enable the development of ultra-compact dual comb spectrometers based on QCLs, and will potentially even act as complete terahertz spectrometers on a chip. This thesis also uses broadband terahertz time-domain spectroscopy to analyze the behavior of THz QCLs. By using QCLs as photoconductive switches, the usual limitations imposed by optical coupling are circumvented, and properties of the laser previously inaccessible can be directly observed. These properties include the gain and absorption of the laser gain medium, the populations of the laser's subbands, and properties of the waveguide like its loss and dispersion. Knowledge of these properties were used to guide frequency comb design, and were also used to inform simulations for designing better lasers.

Download or read book Broadband Terahertz Communication Technologies written by Jianjun Yu and published by Springer Nature. This book was released on 2021-06-28 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the comprehensive knowledge and latest progress in broadband terahertz (THz) technology. THz communication technology is believed to be one of the major choices that succeed the fifth-generation (5G) communication technology. With years of efforts, the author’s team has created a number of world records in the generation, transmission, and reception of ultra wideband THz signal, realizing the MIMO transmission and reception of THz communication, the THz signal transmission with communication capacity of 1 Tbit / s, and the optical fiber and THz integrated transmission. A variety of linear and nonlinear algorithms for multi-carrier and single-carrier THz communication systems are developed, which greatly improves the transmission performance of broadband systems. The book covers in details the broadband THz signal generation, long-distance transmission, and high sensitivity detection. It is of great reference value for researchers, engineers, and graduate students in optical and wireless communications.

Download or read book Investigation of Ultra broadband Terahertz Time domain Spectroscopy with Terahertz Wave Gas Photonics written by Xiaofei Lu and published by . This book was released on 2011 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Terahertz Liquid Photonics written by Xi-cheng Zhang and published by World Scientific. This book was released on 2023-07-26 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Ultra broadband Terahertz Spectroscopy with Terahertz Air Photonics written by Francesco D'Angelo and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Terahertz (THz) spectroscopy is a well-established technique which allows for measuring the complex-valued dielectric properties of materials, specifically semiconductors, in the THz range. As THz photons have a low energy, typically comparable to intraband transitions, they are ideal probes of important phenomena such as the momentum relaxation of charge carriers and optical phonons. Because of the intrinsic phase-matching limitations imposed by the materials employed in conventional THz emitters and detectors, most femtosecond-laser based THz spectrometers can only cover a narrow spectral range, typically 0.1-3 THz. However, by employing the same laser source as conventional THz spectrometers, an air-photonics based THz spectrometer can access a much broader spectral range, extending beyond 30 THz. As air is virtually non-dispersive, the optical-THz phase-matching condition is automatically met. As a result, intense, sub-50-fs electromagnetic transients can be achieved with THz air photonics. The enhanced characteristics in terms of time-resolution, bandwidth, and field strength offer unique opportunities for THz spectroscopy, such as monitoring the dynamics of the charge carriers on the timescale of the carrier-lattice interaction. In this thesis, we explore the capabilities of THz air photonics by performing steady-state ultra-broadband THz spectroscopy of some common polymers, and transient ultra-broadband THz spectroscopy of, respectively, solution processed methylammonium lead iodide perovskite films and undoped gallium arsenide. In addition, we present explicit guidelines for ultra-broadband transient THz spectroscopy, including a novel method for self-referenced signal acquisition minimizing the phase error, and a numerically-accurate approach to the transient reflectance data analysis."--Samenvatting auteur.

Download or read book Terahertz Spectroscopy written by Susan L. Dexheimer and published by CRC Press. This book was released on 2017-12-19 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of new sources and methods in the terahertz spectral range has generated intense interest in terahertz spectroscopy and its application in an array of fields. Presenting state-of-the-art terahertz spectroscopic techniques, Terahertz Spectroscopy: Principles and Applications focuses on time-domain methods based on femtosecond laser sources and important recent applications in physics, materials science, chemistry, and biomedicine. The first section of the book examines instrumentation and methods for terahertz spectroscopy. It provides a comprehensive treatment of time-domain terahertz spectroscopic measurements, including methods for the generation and detection of terahertz radiation, methods for determining optical constants from time-domain measurements, and the use of femtosecond time-resolved techniques. The last two sections explore a variety of applications of terahertz spectroscopy in physics, materials science, chemistry, and biomedicine. With chapters contributed by leading experts in academia, industry, and research, this volume thoroughly discusses methods and applications, setting it apart from other recent books in this emerging terahertz field.

Download or read book Modern Techniques of Spectroscopy written by Dheeraj Kumar Singh and published by Springer Nature. This book was released on 2021-04-01 with total page 663 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book highlights recent developments in the field of spectroscopy by providing the readers with an updated and high-level of overview. The focus of this book is on the introduction to concepts of modern spectroscopic techniques, recent technological innovations in this field, and current examples of applications to molecules and materials relevant for academia and industry. The book will be beneficial to researchers from various branches of science and technology, and is intended to point them to modern techniques, which might be useful for their specific problems. Spectroscopic techniques, that are discussed include, UV-Visible absorption spectroscopy, XPS, Raman spectroscopy, SERS, TERS, CARS, IR absorption spectroscopy, SFG, LIBS, Quantum cascade laser (QCL) spectroscopy, fluorescence spectroscopy, ellipsometry, cavity-enhanced absorption spectroscopy, such as cavity ring-down spectroscopy (CRDS) and evanescent wave-CRDS both in gas and condensed phases, time-resolved spectroscopy etc. Applications introduced in the different chapters demonstrates the usefulness of the spectroscopic techniques for the characterization of fundamental properties of molecules, e.g. in connection with environmental impact, bio-activity, or usefulness for pharmaceutical drugs, and materials important e.g. for nano-science, nuclear chemistry, or bio-applications. The book presents how spectroscopic techniques can help to better understand substances, which have also great impact on questions of social and economic relevance (environment, alternative energy, etc.).

Download or read book Metamaterial Electromagnetic Wave Absorbers written by Willie J. Padilla and published by Morgan & Claypool Publishers. This book was released on 2022-01-24 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic metamaterials are a family of shaped periodic materials which achieve extraordinary scattering properties that are difficult or impossible to achieve with naturally occurring materials. This book focuses on one such feature of electromagnetic metamaterials—the theory, properties, and applications of the absorption of electromagnetic radiation. We have written this book for undergraduate and graduate students, researchers, and practitioners, covering the background and tools necessary to engage in the research and practice of metamaterial electromagnetic wave absorbers in various fundamental and applied settings. Given the growing impact of climate change, the call for innovations that can circumvent the use of conventional energy sources will be increasingly important. As we highlight in Chapter 6, the absorption of radiation with electromagnetic metamaterials has been used for energy harvesting and energy generation, and will help to reduce reliance on fossil fuels. Other applications ranging from biochemical sensing to imaging are also covered. We hope this book equips interested readers with the tools necessary to successfully engage in applied metamaterials research for clean, sustainable energy. This book consists of six chapters. Chapter 1 provides an introduction and a brief history of electromagnetic wave absorbers; Chapter 2 focuses on several theories of perfect absorbers; Chapter 3 discusses the scattering properties achievable with metamaterial absorbers; Chapter 4 provides significant detail on the fabricational processes; Chapter 5 discusses examples of dynamical absorbers; and Chapter 6 highlights applications of metamaterial absorbers.

Download or read book Introduction to THz Wave Photonics written by Xi-Cheng Zhang and published by Springer Science & Business Media. This book was released on 2009-12-01 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Sensing with Terahertz Radiation written by Daniel Mittleman and published by Springer. This book was released on 2013-02-26 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is two-fold. First, the various different methods of accessing the THz range are discussed, with a view to convince the reader that there have been qualitative and significant improvements over older, more conventional techniques. The text makes it clear that these improvements enable practical "real-world" applications of THz technology, in a manner which would not have been possible before. Second, the demonstrations and feasibility tests described serve as compelling evidence of the utility of such devices. Due to the unique characteristics of THz radiation and its interaction with materials, these devices have substantial advantages over other competing technologies in a number of different areas.

Download or read book Terahertz Spectroscopy and Imaging written by Kai-Erik Peiponen and published by Springer. This book was released on 2012-10-04 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Broadband Terahertz Emission from Photoconductive Devices written by Salman Alfihed and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter explores the terahertz (THz) emission from biased semiconductor photoconductive devices. The photoconductive device is an optoelectronic device that is able to emit broadband THz radiation under the optical excitation, by an ultrafast laser, in the existence of a bias field. This chapter explains the basic principle of photoconductive devices with focusing on the main device components, being the photoconductive material and the photoconductive structure. Then, various materials and structures are discussed toward improving the performance of the photoconductive THz emitters. Furthermore, the main limitations and considerations are presented with insight into the different saturation and screening effects due to the bias field and pump fluence. Ultimately, the recent advances and studies of photoconductive THz emitters are presented in terms of material and structure, including the quantum dots, the nanostructure, the use of dielectric materials, and the grating structure on the photoconductive surfaces.

Download or read book Principles of Terahertz Science and Technology written by Yun-Shik Lee and published by Springer Science & Business Media. This book was released on 2009-03-02 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Terahertz Science and Technology aims to elucidate the fundamentals of THz technology and science for potential new users. It surveys major techniques of generating, detecting, and manipulating THz waves and also discusses a number of essential processes where THz waves interact with physical, chemical, and biological systems. This book serves as an introduction to THz technology for new researchers in various fields. Many different disciplines, such as ultrafast spectroscopy, semiconductor device fabrication, bio-medical imaging and more, involve the recent development of THz technology. It is necessary to lay down a strong, common foundation among researchers, so that communication can proceed smoothly. Previous THz research activities have concentrated on generation and detection, but the focus has now shifted to practical applications of this technology, such as high-speed optoelectronic signal processing and molecular spectroscopy. Drawing upon years of practical experience and using numerous examples and illustrative applications Yun-Shik Lee discusses: The major techniques of generating, detecting, and manipulating THz waves Essential processes where THz waves interact with physical, chemical, and biological systems Medical Applications of T-Ray Imaging including, optical properties of human tissue, cancer diagnostics, reflective imaging of skin burns and detection of dental caries Principles of Terahertz Science and Technology is an ideal book for applied physicists, microwave engineers, biomedical engineers, electrical engineers, and analytical chemists interested in the fundamentals and applications of THz engineering.

Download or read book Fundamentals of Terahertz Devices and Applications written by Dimitris Pavlidis and published by John Wiley & Sons. This book was released on 2021-08-02 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative and comprehensive guide to the devices and applications of Terahertz technology Terahertz (THz) technology relates to applications that span in frequency from a few hundred GHz to more than 1000 GHz. Fundamentals of Terahertz Devices and Applications offers a comprehensive review of the devices and applications of Terahertz technology. With contributions from a range of experts on the topic, this book contains in a single volume an inclusive review of THz devices for signal generation, detection and treatment. Fundamentals of Terahertz Devices and Applications offers an exploration and addresses key categories and aspects of Terahertz Technology such as: sources, detectors, transmission, electronic considerations and applications, optical (photonic) considerations and applications. Worked examplesbased on the contributors extensive experience highlight the chapter material presented. The text is designed for use by novices and professionals who want a better understanding of device operation and use, and is suitable for instructional purposes This important book: Offers the most relevant up-to-date research information and insight into the future developments in the technology Addresses a wide-range of categories and aspects of Terahertz technology Includes material to support courses on Terahertz Technology and more Contains illustrative worked examples Written for researchers, students, and professional engineers, Fundamentals of Terahertz Devices and Applications offers an in-depth exploration of the topic that is designed for both novices and professionals and can be adopted for instructional purposes.

Download or read book Terahertz Metrology written by Mira Naftaly and published by Artech House. This book was released on 2015-01-01 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new book describes modern terahertz (THz) systems and devices and presents practical techniques for accurate measurement with an emphasis on evaluating uncertainties and identifying sources of error. This is the first THz book on the market to address measurement methodologies and issues -- perfect for practitioners and aspiring practitioners wishing to learn good measurement practice and avoid pitfalls. This book provides a brief review of different THz systems and devices, followed by chapters detailing the measurement issues encountered in using each of the main types of THz systems, and a guide to performing measurements rigorously. Particular attention is given to evaluating uncertainties, and recognizing potential sources of errors. The main focus is on time-domain spectroscopy, by far the most widely used technique. Readers are also presented with examples of applications with the emphasis on utility, both in research and in industry.

Download or read book Millimeter wave and Terahertz Photonics written by Dieter Jäger and published by SPIE-International Society for Optical Engineering. This book was released on 2006 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.

Download or read book Microwave and Terahertz Photonics written by Andreas Stöhr and published by SPIE-International Society for Optical Engineering. This book was released on 2004 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.