Plasma harmonics is a new field of laser spectroscopy. The use of the solid elements of the periodic table, together with thousands of complex solid-state samples, largely extends the range of materials employed in plasma harmonics in contrast to the few light rare gases that are typically used. Thus the exploration of practically any available solid-state material through nonlinear spectroscopy comprising laser ablation and harmonic generation can be considered a new tool for materials science. Plasma harmonic spectroscopy exploits the spectral and structural properties of various ablated solid-state materials by propagating short laser pulses through laser-produced plasma and generating high-order harmonics of ultrashort laser pulses. The book describes the special features of plasma harmonics in laser-produced ablation plumes and discusses a wide range of nonlinear medium characteristics that can be produced by varying the conditions of laser plume production on the surface of a solid. This book compiles and details cutting-edge research in science and medicine from the interdisciplinary team of the Michigan Nanotechnology Institute for Medicine and Biological Sciences, who are currently revolutionizing drug delivery techniques through the development of engineered nanodevices. Edited by Istvan J Majoros and James Baker, Jr., two prominent nanotechnology researchers, this book is designed for workers involved in nanotechnology, macromolecular science, cancer therapy, or drug delivery research.

This book comprises a detailed consideration of novel approaches developed in the field of frequency conversion of laser sources in laser-induced plasmas during the last few years. The aim of the book is to support researchers and other readers in their development in the area of high-order nonlinear spectroscopy. Particularly, the advanced studies of nanoparticles and quantum dots for the formation of new sources of radiation in different short-wavelength spectral ranges show the ways to further implement the specific features of small-sized species in a relatively new field of study—laser ablation induced high-order harmonics generation spectroscopy. Researchers involved in the development of new methods of frequency conversion will benefit from finding the most recent advances in this field. Undergraduate students will discover interesting information about recent findings in plasma harmonic research. Additionally, the usefulness of the book will be demonstrated by the potential applications of the new knowledge developed during recent years for ultrafast pulse generation using the proposed schemes of plasma-light interaction. Thus, the audience may also include those researchers involved in state-of-the-art developments in attophysics. Additionally, any professionals interested in the application of the advanced techniques for material science will also benefit from updating their knowledge of new methods of material studies using high-order nonlinear spectroscopy.

This book represents the first comprehensive treatment of high-order harmonic generation in laser-produced plumes, covering the principles, past and present experimental status and important applications. It shows how this method of frequency conversion of laser radiation towards the extreme ultraviolet range matured over the course of multiple studies and demonstrated new approaches in the generation of strong coherent short-wavelength radiation for various applications. Significant discoveries and pioneering contributions of researchers in this field carried out in various laser scientific centers worldwide are included in this first attempt to describe the important findings in this area of nonlinear spectroscopy. High-Order Harmonic Generation in Laser Plasma Plumes is a self-contained and unified review of the most recent achievements in the field, such as the application of clusters (fullerenes, nanoparticles, nanotubes) for efficient harmonic generation of ultrashort laser pulses in cluster-containing plumes and resonance-induced enhancement of harmonic yield. It can be used as an advanced monograph for researchers and graduate students working in the field of nonlinear spectroscopy. It is also suitable for researchers in laser physics and nonlinear optics who wish to have an overview of the advanced achievements in laser ablation-induced high-order harmonic generation spectroscopy. The carefully presented details of this book will be of value to research devoted to the understanding and control frequency conversion of laser pulses in plasma plumes. The studies described in this book pave the way for the development of a new method of materials studies using the laser ablation-induced high-order harmonic generation spectroscopy, which can exploit the spectral and structural properties of various solid-state materials through their ablation and further propagation of short laser pulse through laser-produced plasma and generation of high-order harmonics.

This book offers a review of the use of extended ablation plasmas as nonlinear media for HHG of high-order harmonic generation (HHG). The book describes the different experimental approaches, shows the advantages and limitations regarding HHG efficiency and discusses the particular processes that take place at longer interaction lengths, including propagation and quasi-phase matching effects. It describes the most recent approaches to harmonic generation in the extreme ultraviolet (XUV) range with the use of extended plasma plumes, and how these differ from more commonly-used gas-jet sources. The main focus is on studies using extended plasmas, but some new findings from HHG experiments in narrow plasma plumes are also discussed. It also describes how quasi-phase-matching in modulated plasmas, as demonstrated in recent studies, has revealed different means of tuning enhanced harmonic groups in the XUV region. After an introduction to the fundamental theoretical and experimental aspects of HHG, a review of the most important results of HHG in narrow plasmas is presented, including recent studies of small-sized plasma plumes as emitters of high-order harmonics. In Chapter 2, various findings in the application of extended plasmas for harmonic generation are analyzed. One of the most important applications of extended plasmas, the quasi-phase-matching of generated harmonics, is demonstrated in Chapter 3, including various approaches to the modification of perforated plasma plumes. Chapter 4 depicts the nonlinear optical features of extended plasmas produced on the surfaces of different non-metal materials. Chapter 5 is dedicated to the analysis of new opportunities for extended plasma induced HHG. The advantages of the application of long plasma plumes for HHG, such as resonance enhancement and double-pulse method, are discussed in Chapter 6. Finally, a summary section brings together all of these findings and discuss the perspectives of extended plasma formations for efficient HHG and nonlinear optical plasma spectroscopy. The book will be useful for students and scholars working in this highly multidisciplinary domain involving material science, nonlinear optics and laser spectroscopy. It brings the new researcher to the very frontier of the physics of the interaction between laser and extended plasma; for the expert it will serve as an essential guide and indicate directions for future research.

A comprehensive guide to a new technology for enabling high-performance spectroscopy and laser sources Resonance Enhancement in Laser-Produced Plasmas offers a guide to the most recent findings in the newly emerged field of resonance-enhanced high-order harmonic generation using the laser pulses propagating through the narrow and extended laser-produced plasma plumes. The author—a noted expert in the field—presents an introduction and the theory that underpin the roles of resonances in harmonic generation. The book also contains a review of the most advanced methods of plasma harmonics generation at the conditions of coincidence of some harmonics, autoionizing states, and some ionic transitions possessing strong oscillator strengths. Comprehensive in scope, this text clearly demonstrates the importance of resonance-enhanced nonlinear optical effects leading to formation of efficient sources of coherent extreme ultraviolet radiation that can be practically applied. This important resource: Puts the focuses on novel applications of laser-plasma physics, such as the development of ultrashort-wavelength coherent light sources Details both the theoretical and experimental aspects of higher-order harmonic generation in laser-produced plasmas Contains information on early studies of resonance enhancement of harmonics in metal-ablated plasmas Analyzes the drawbacks of different theories of resonant high order harmonic generation Includes a discussion of the quasi-phase-matching and properties of semiconductor plasmas Written for researchers and students in the fields of physics, materials science, and electrical engineering who are interested in laser physics and optics, Resonance Enhancement in Laser-Produced Plasmas offers an introduction to the topic and covers recent experimental studies of various resonance processes in plasmas leading to enhancement of single harmonic.

It is interesting to analyze the application of mid-infrared (MIR, 1000-5000 nm) radiation to study the dynamics of the nonlinear optical response of ablated molecular structures compared with commonly used Ti: sapphire lasers for plasma high-order harmonic generation (HHG), including the studies of extended harmonics at a comparable conversion efficiency with shorter wavelength laser sources, and a search for new opportunities in improvement of the HHG conversion efficiency in the mid-IR range, such as the application of clustered molecules. This book shows the most recent findings of various new schemes of the application of MIR pulses for HHG in laser-produced low-ionised, low-density plasma plumes, which could be dubbed for simplicity as 'plasma harmonics'. The use of any element of the periodic table, as well as thousands of complex samples that exist as solids largely extends the range of materials employed, whereas only a few rare gases are typically available for gas HHG. The exploration of practically any solid-state material through the nonlinear spectroscopy comprising laser ablation and harmonic generation can be considered as a new tool for materials science. Thus the MIR pump based laser-ablation-induced high-order harmonic generation spectroscopy can be considered a new method for the study of materials and one of most important applications of plasma HHG.

This book is mostly concerned on the experimental research of the nonlinear optical characteristics of various media, low- and high-order harmonic generation in different materials, and formation, and nonlinear optical characterization of clusters. We also demonstrate the inter-connection between these areas of nonlinear optics. Nonlinear optical properties of media such as optical limiting can be applied in various areas of science and technology. To define suitable materials for these applications, one has to carefully analyse the nonlinear optical characteristics of various media, such as the nonlinear refractive indices, coefficients of nonlinear absorption, saturation absorption intensities, etc. Knowing the nonlinear optical parameters of materials is also important for describing the propagation effects, self-interaction of intense laser pulses, and optimisation of various nonlinear optical processes. Among those processes one can admit the importance of the studies of the frequency conversion of coherent laser sources. The area of interest for nonlinear optical characterization of materials is also closely related with new field of nanostructures formation and application during laser-matter interaction. We show how the nonlinear optical analysis of materials leads to improvement of their high-order nonlinear optical response during the interaction with strong laser fields. Ablation-induced nanoparticles formation is correlated with their applications as efficient sources of coherent short-wavelength photons. From other side, recent achievements of harmonic generation in plasmas are closely related with the knowledge of the properties of materials in the laser plumes. All of these studies are concerned with the low-order nonlinear optical features of various materials. The novelty of the approach developed in present book is related with inter-connection of those studies with each other.