Download or read book A Study of Electron and Phonon Dynamics by Broadband Two dimensional THz Time domain Spectroscopy written by Zhengping Fu and published by . This book was released on 2016 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Terahertz Time domain Spectroscopy of Two dimensional Electron Gasses at High Magnetic Fields written by Jeremy A. Curtis and published by . This book was released on 2016 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation covers two projects that were in the logical path to studying decoherence in a high mobility GaAs two-dimensional electron gas at high magnetic fields. The first project is the ultrafast non-degenerate pump-probe spectroscopic study of bulk GaAs in the Split Florida Helix at the National High Magnetic Field Laboratory at Florida State University. This project was undertaken as a proof of concept that ultrafast optics could be done in the Split Florida Helix so that we might study a high mobility two dimensional electron gas using THz time-domain spectroscopy at high magnetic fields, which is a much more complicated measurement than the pump-probe discussed here. This demonstration was a success. We completed the first ultrafast optical study of any kind in the Florida Split Helix. We collected differential reflection data from this bulk sample that exhibited electronic and oscillatory components. These components were treated independently in the analysis by treating the electronic dynamics with a four level approximation. The electronic transition rates were extracted and agreed well with published values. This agreement is a demonstration that the spectrometer functioned as desired. The oscillatory response was found to be a result of the emission of coherent phonons upon electronic transition between the four levels. The frequency of the oscillatory response was extracted and agreed well with the theoretical value. The second project is the study of the temperature dependence of the cyclotron decay lifetimes in a Landau quantized GaAs high mobility two dimensional electron gas using THz time-domain spectroscopy at relatively low magnetic field (1.25 T). We find that the cyclotron decay lifetimes decrease monotonically with increasing temperature from 0.4 K to 100 K and that the primary pulse amplitudes increase from 0.4 K to 1.2 K, saturates above 1.2 K up to 50 K, and decreases rapidly above 50 K. We attribute this rapid drop in amplitude above 50 K as well as the high temperature behavior of the cyclotron resonance decay times to polar optical phonon scattering. We find that the dissipative component of the measured cyclotron decay lifetimes can not be well approximated by a DC scattering lifetime model, which includes polar optical phonon scattering, remote ionized impurity scattering, acoustic deformation potential scattering, and piezo-electric scattering. This discrepancy is due to the entirely different distribution of the Fermi surface resulting from the Landau quantization of the quantum well's states. This project demonstrates the type of measurements we would like to conduct at higher magnetic fields using more broadband THz sources. Future work is finally discussed, which outlines the construction and demonstration of a custom ultra broadband THz time-domain spectrometer for use in the Florida Split Helix. The data collected is not of sufficient quality to extract physical meaning due to its decreased signal to noise and bandwidth relative to the test of the system through the magnet without sample or windows at 0 T and 300 K, which demonstrated the generation and detection of 15 THz of usable bandwidth. This reduction in signal to noise and bandwidth is due to clipping the THz beam on the magnet aperture. Future measurements will use optically clear windows that are also transparent in the THz so that alignment of the THz beam may be done with an optical beam. While the original goal was an extension of the temperature dependent measurements described in the previous paragraph at much higher applied magnetic field strength, the design, construction, and demonstration of the system without sample or windows as well as the data set collected through a high mobility GaAs two dimensional electron gas at 25 T and 15 K constitutes the first THz time-domain measurements conducted in the Florida Split Helix.

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 Terahertz field induced Nonlinearity in Phonons Electrons and Spins written by Xian Li (Ph.D.) and published by . This book was released on 2019 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, I describe work aimed at understanding nonlinear material responses initiated by strong terahertz (THz) field excitation. I discuss two aspects of nonlinear THz spectroscopy in condensed-matter materials: developments of experimental THz capabilities and spectroscopy methods and their applications in investigating ultrafast nonlinear dynamics in different classes of materials. I first describe the THz generation, detection and spectroscopy methods, which are the basis of all of our studies. We have generated strong single- and multi-cycle THz pulses covering several spectral ranges using inorganic and organic crystals and developed linear and nonlinear THz spectroscopy techniques to interrogate light-matter interactions based on different observables and/or symmetry criteria. We have demonstrated a new method for studying time-domain electron paramagnetic resonance that allows us to measure THz-frequency fine structures of spin energy levels on a tabletop and have developed nonlinear two-dimensional (2D) magnetic resonance spectroscopy to distinguish nonlinear THz-spin interaction pathways. We also show that THz-pump, optical-probe spectroscopy, including THz field-induced second-harmonic generation spectroscopy and THz Kerr effect spectroscopy, can be extended to study phase transitions in quantum paraelectric and topological materials. We have employed the THz methods to drive and detect nonlinear responses from several degrees of freedom in the materials. We have demonstrated collective coherent control over material structure by inducing a quantum paraelectric to ferroelectric phase transition using intense THz electric fields in strontium titanate. We show that a single-cycle THz field is able to drive ions along the microscopic pathway leading directly to their locations in a new crystalline phase on an ultrafast timescale. We have driven highly nonlinear lattice and electronic responses in a topological crystalline insulator by dynamically perturbing the protecting crystalline symmetry through THz phonon excitation. We have observed oscillations in optical reflectivity that may be associated with electronic gap opening and modulation in the topological surface states. Finally, we have demonstrated nonlinear manipulation of collective spin waves in a canted antiferromagnet using strong THz magnetic fields and we have observed full sets of the second- and third-order nonlinear responses in 2D THz magnetic resonance spectra, which are accurately reproduced in our numerical simulations.

Download or read book Intense Terahertz Excitation of Semiconductors written by Sergey Ganichev and published by OUP Oxford. This book was released on 2005-12-15 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intense Terahertz Excitation of Semiconductors presents the first comprehensive treatment of high-power terahertz applications to semiconductors and low-dimensional semiconductor structures. Terahertz properties of semiconductors are in the center of scientific activities because of the need of high-speed electronics. This research monograph brigdes the gap between microwave physics and photonics. It focuses on a core topic of semiconductor physics providing a full description of the state of the art of the field. _ The reader is introduced to new physical phenomena which occur in the terahertz frequency range at the transition from semi-classical physics with a classical field amplitude to the fully quantized limit with photons. The book covers a wide range of optical, optoelectronic, and nonlinear transport processes, presenting experimental results, clearly visualizing models and basic theories. Background information for future work and exhaustive references of current literature are given. A particularly valuable feature is through the discussion of various technical aspects of the terahertz range like the generation of high-power coherent radiation, optical components, instrumentation, and detection schemes of short intense radiation impulses. The book complements, for the first time in form of a monograph, previous books on infrared physics which dealt with low-power optical and opto-electronic processes. It will be useful not only to scientists but also to advanced students who are interested in terahertz research.

Download or read book Molecular and Laser Spectroscopy written by V.P. Gupta and published by Elsevier. This book was released on 2020-07-10 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular and Laser Spectroscopy, Advances and Applications: Volume 2 gives students and researchers an up-to-date understanding of the fast-developing area of molecular and laser spectroscopy. This book covers basic principles and advances in several conventional as well as new and upcoming areas of molecular and laser spectroscopy, such as a wide range of applications in medical science, material science, standoff detection, defence and security, chemicals and pharmaceuticals, and environmental science. It covers the latest advancements, both in terms of techniques and applications, and highlights future projections. Editors V.P. Gupta and Yukihiro Ozaki have brought together eminent scientists in different areas of spectroscopy to develop specialized topics in conventional molecular spectroscopy (Cavity ringdown, Matrix Isolation, Intense THz, Far- and Deep- UV, Optogalvanic ), linear and nonlinear laser spectroscopy (Rayleigh & Raman Scattering), Ultrafast Time-resolved spectroscopy, and medical applications of molecular spectroscopy. and advanced material found in research articles. This new volume expands upon the topics covered in the first volume for scientists to learn the latest techniques and put them to practical use in their work. Covers several areas of spectroscopy research and expands upon topics covered in the first volume Includes exhaustive lists of research articles, reviews, and books at the end of each chapter to further learning objectives Uses illustrative examples of the varied applications to provide a practical guide to those interested in using molecular and laser spectroscopy tools in their research

Download or read book Journal of the Physical Society of Japan written by and published by . This book was released on 2014 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Encyclopedia of Modern Optics written by Bob D. Guenther and published by Academic Press. This book was released on 2018-02-14 with total page 2253 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia of Modern Optics, Second Edition, Five Volume Set provides a wide-ranging overview of the field, comprising authoritative reference articles for undergraduate and postgraduate students and those researching outside their area of expertise. Topics covered include classical and quantum optics, lasers, optical fibers and optical fiber systems, optical materials and light-emitting diodes (LEDs). Articles cover all subfields of optical physics and engineering, such as electro-optical design of modulators and detectors. This update contains contributions from international experts who discuss topics such as nano-photonics and plasmonics, optical interconnects, photonic crystals and 2D materials, such as graphene or holy fibers. Other topics of note include solar energy, high efficiency LED’s and their use in illumination, orbital angular momentum, quantum optics and information, metamaterials and transformation optics, high power fiber and UV fiber lasers, random lasers and bio-imaging. Addresses recent developments in the field and integrates concepts from fundamental physics with applications for manufacturing and engineering/design Provides a broad and interdisciplinary coverage of specialist areas Ensures that the material is appropriate for new researchers and those working in a new sub-field, as well as those in industry Thematically arranged and alphabetically indexed, with cross-references added to facilitate ease-of-use

Download or read book Time resolved THz Studies of Carrier Dynamics in Semiconductors Superconductors and Strongly correlated Electron Materials written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Perhaps the most important aspect of contemporary condensed matter physics involves understanding strong Coulomb interactions between the large number of electrons in a solid. Electronic correlations lead to the emergence of new system properties, such as metal-insulator transitions, superconductivity, magneto-resistance, Bose-Einstein condensation, the formation of excitonic gases, or the integer and fractional Quantum Hall effects. The discovery of high-Tc superconductivity in particular was a watershed event, leading to dramatic experimental and theoretical advances in the field of correlated-electron systems. Such materials often exhibit competition between the charge, lattice, spin, and orbital degrees of freedom, whose cause-effect relationships are difficult to ascertain. Experimental insight into the properties of solids is traditionally obtained by time-averaged probes, which measure e.g., linear optical spectra, electrical conduction properties, or the occupied band structure in thermal equilibrium. Many novel physical properties arise from excitations out of the ground state into energetically higher states by thermal, optical, or electrical means. This leads to fundamental interactions between the system's constituents, such as electron-phonon and electron-electron interactions, which occur on ultrafast timescales. While these interactions underlie the physical properties of solids, they are often only indirectly inferred from time-averaged measurements. Time-resolved spectroscopy, consequently, is playing an ever increasing role to provide insight into light-matter interaction, microscopic processes, or cause-effect relationships that determine the physics of complex materials. In the past, experiments using visible and near-infrared femtosecond pulses have been extensively employed, e.g. to follow relaxation and dephasing processes in metals and semiconductors. However, many basic excitations in strongly-correlated electron systems and nanoscale materials occur at lower energies. The terahertz (THz) regime is particularly rich in such fundamental resonances. This includes ubiquitous lattice vibrations and low-energy collective oscillations of conduction charges. In nanoscale materials, band structure quantization also yields novel infrared and THz transitions, including intersubband absorption in quantum wells. The formation of excitons in turn leads to low-energy excitations analogous to inter-level transitions in atoms. In transition-metal oxides, fundamental excitation gaps arise from charge pairing into superconducting condensates and other correlated states. This motivates the use of ultrafast THz spectroscopy as a powerful tool to study light-matter interactions and microscopic processes in nanoscale and correlated-electron materials. A distinct advantage of coherent THz pulses is that the amplitude and phase of the electric field can be measured directly, as the THz fields are coherent with the fs pulses from which they are generated. Using THz time-domain spectroscopy (THz-TDS), both the real and imaginary parts of the response functions (such as the dielectric function) are obtained directly without the need for Kramers?Kronig transforms. The THz response can also be expressed in terms of absorption and refractive index, or as the optical conductivity. The optical conductivity describes the current response of a many-body system to an electric field, an ideal tool to study conducting systems. A second important advantage is the ultrafast time resolution that results from the short temporal duration of the THz time-domain sources. In particular, optical-pump THz-probe spectroscopy enables a delicate probe of the transient THz conductivity after optical photoexcitation. These experiments can provide insight into quasiparticle interactions, phase transitions, or nonequilibrium dynamics. In this chapter we will provide many such examples. Since THz spectroscopy of solids is a quickly expanding field.

Download or read book Broadband Dielectric Spectroscopy written by Friedrich Kremer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both an introductory course to broadband dielectric spectroscopy and a monograph describing recent dielectric contributions to current topics, this book is the first to cover the topic and has been hotly awaited by the scientific community.

Download or read book Nuncius written by and published by . This book was released on 2005 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annali di storia della scienza.

Download or read book Concepts and Applications of Nonlinear Terahertz Spectroscopy written by Thomas Elsaesser and published by Morgan & Claypool Publishers. This book was released on 2019-02-22 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Terahertz (THz) radiation with frequencies between 100 GHz and 30 THz has developed into an important tool of science and technology, with numerous applications in materials characterization, imaging, sensor technologies, and telecommunications. Recent progress in THz generation has provided ultrashort THz pulses with electric field amplitudes of up to several megavolts/cm. This development opens the new research field of nonlinear THz spectroscopy in which strong light-matter interactions are exploited to induce quantum excitations and/or charge transport and follow their nonequilibrium dynamics in time-resolved experiments. This book introduces methods of THz generation and nonlinear THz spectroscopy in a tutorial way, discusses the relevant theoretical concepts, and presents prototypical, experimental, and theoretical results in condensed matter physics. The potential of nonlinear THz spectroscopy is illustrated by recent research, including an overview of the relevant literature.

Download or read book Spectroscopic Ellipsometry written by Hiroyuki Fujiwara and published by John Wiley & Sons. This book was released on 2007-09-27 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ellipsometry is a powerful tool used for the characterization of thin films and multi-layer semiconductor structures. This book deals with fundamental principles and applications of spectroscopic ellipsometry (SE). Beginning with an overview of SE technologies the text moves on to focus on the data analysis of results obtained from SE, Fundamental data analyses, principles and physical backgrounds and the various materials used in different fields from LSI industry to biotechnology are described. The final chapter describes the latest developments of real-time monitoring and process control which have attracted significant attention in various scientific and industrial fields.

Download or read book Organic Electro Optics and Photonics written by Larry R. Dalton and published by Cambridge University Press. This book was released on 2015-07-30 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Definitive guide to modern organic electro-optic and photonic technologies, from basic theoretical concepts to practical applications in devices and systems.

Download or read book Two Dimensional Optical Spectroscopy written by Minhaeng Cho and published by CRC Press. This book was released on 2009-06-16 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-Dimensional Optical Spectroscopy discusses the principles and applications of newly emerging two-dimensional vibrational and optical spectroscopy techniques. It provides a detailed account of basic theory required for an understanding of two-dimensional vibrational and electronic spectroscopy. It also bridges the gap between the formal developm

Download or read book Springer Handbook of Lasers and Optics written by Frank Träger and published by Springer Science & Business Media. This book was released on 2012-05-05 with total page 1704 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book 2D Monoelemental Materials Xenes and Related Technologies written by Zongyu Huang and published by CRC Press. This book was released on 2022-04-19 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monoelemental 2D materials called Xenes have a graphene-like structure, intra-layer covalent bond, and weak van der Waals forces between layers. Materials composed of different groups of elements have different structures and rich properties, making Xenes materials a potential candidate for the next generation of 2D materials. 2D Monoelemental Materials (Xenes) and Related Technologies: Beyond Graphene describes the structure, properties, and applications of Xenes by classification and section. The first section covers the structure and classification of single-element 2D materials, according to the different main groups of monoelemental materials of different components and includes the properties and applications with detailed description. The second section discusses the structure, properties, and applications of advanced 2D Xenes materials, which are composed of heterogeneous structures, produced by defects, and regulated by the field. Features include: Systematically detailed single element materials according to the main groups of the constituent elements Classification of the most effective and widely studied 2D Xenes materials Expounding upon changes in properties and improvements in applications by different regulation mechanisms Discussion of the significance of 2D single-element materials where structural characteristics are closely combined with different preparation methods and the relevant theoretical properties complement each other with practical applications Aimed at researchers and advanced students in materials science and engineering, this book offers a broad view of current knowledge in the emerging and promising field of 2D monoelemental materials.