This book introduces readers to the development of a new generation of high pulse-repetition frequency instruments for multi-dimensional attosecond-resolution photoelectron spectroscopy (attosecond PES). It investigates the power scaling of femtosecond enhancement cavities for efficient intracavity high-harmonics generation (HHG). Further, it derives and verifies advanced resonator designs that feature large illuminated spots on all mirrors, which mitigate both intensity- and thermally-induced enhancement limitations. The dynamics of a high-finesse, passive resonator in the presence of a highly nonlinear optical process such as HHG are quantitatively investigated, both theoretically and experimentally. These investigations are instrumental in achieving the holistic optimization of the XUV source reported on here, which for the first time reached intracavity HHG conversion efficiencies comparable to those achieved in single-pass setups with a similar gas target. Coupling out the XUV beam from the enhancement cavity by purely geometric means, employing both the fundamental and higher-order transverse Gaussian modes, is studied. This offers the advantages of robustness, low distortion to the participating pulses, and photon-energy scalability. Last but not least, the author provides a range of proof-of-principle attosecond angle-resolved PES experiments. The book gives an outlook on the possible future development of cavity-enhanced HHG and an extensive discussion on the generation of isolated XUV attosecond pulses via intracavity wavefront rotation.

Optical Resonators provides a detailed discussion of the properties of optical resonators for lasers from basic theory to recent research. In addition to describing the fundamental theories of resonators such as geometrical optics, diffraction, and polarisation the characteristics of all important resonator schemes and their calculation are presented. Experimental examples, practical problems and a collection of measurement techniques support the comprehensive treatment of the subject. Optical Resonators is the only book currently available that provides a comprehensive overview of the the subject. Combined with the structure of the text and the autonomous nature of the chapters this work will be as suitable for those new to the field as it will be invaluable to specialists conducting research.

Enhancement cavities are passive optical resonators in which continuous-wave laser radiation or pulses of a frequency comb are coherently overlapped, allowing for a power and intensity scaling of up to several orders of magnitude. A prominent application is the table-top generation of bright, laser-like radiation in spectral regions where direct laser action is inefficient or not available at all, via intracavity nonlinear optical processes. However, to exploit the full capacity of this technique further progress is needed. This thesis covers central problems of enhancement cavities, such as finding limitations in scaling the circulating power, measuring cavity parameters with high accuracy, tailoring transverse modes and coupling out radiation generated in the cavity. Unprecedented intracavity laser powers were demonstrated, surpassing previous results by an order of magnitude. As an application, harmonics of the fundamental 1040-nm radiation up to the 21st order are generated. Besides reporting these fine experimental results, the thesis provides an excellent introduction into the physics of enhancement cavities, supported by more than 140 references.

After laying the foundation by explaining the fundamental principles of light propagation and optical resonators, this book delves into the realm of implementing resonators through a fiber-based approach. It extensively explores fiber-based resonators, encompassing a comprehensive discussion spanning from their intricacies of design to their pivotal roles in advancing quantum optics experiments. Furthermore, it details the design techniques, meticulously explaining the latest developments within this dynamic field. There are vivid illustrations highlighting the various applications of resonators in experimental optics and cavity quantum electrodynamics. Also, a discourse is presented regarding the future potential of fiber-based resonators in quantum technology. The book serves as a valuable resource for individuals with an interest in optical resonators and their boundless possibilities.

The article is dedicated to an analysis of the properties of a controlled open resonator with spheric mirrors and its application for measurements in the laser field. The requirements for measurement optimization are stated. From the experimental results the advantage is deduced of applying the resonators for measuring the frequency spectra of lasers and of passive optical resonators, for determining the quality of laser elements and for using an interferometer with an active medium in the measurement of losses and gain of discharge tubes for gas lalasers. (Author).

This book contains most, but regrettably not all, the papers that were presented at The Advanced Research Workshop, held July 1-5, 1997, at Smolenice Castle, Slovak Republic. The problem of angular divergence is of great importance in quantum electronics: low divergence is required not only in most of practical laser applications, but also for achieving high efficiency of parametric laser frequency conversion, and harmonic generation. The large volume of available studies aimed at improving the pump systems and the spectroscopic properties of lasing media, brought about no more than 2-3 fold increases in laser efficiency, while concurrent studies of angular divergence and the implementation of the findings, resulted in several order of magnitude of increases in radiance. The spatial beam structure that is formed in the laser cavity together with the active element constitute the most critical laser elements. The engineering devices, such as excitation systems, lasing gas circulation systems, etc., are usually at the top of the agenda of scientific meetings and of gatherings of engineering experts. The divergence problem has never been discussed by a broad community of experts in this field.

Over the last century, numerous optical techniques have been developed to characterize materials, giving insight into their optical, electronic, magnetic, and structural properties and elucidating such diverse phenomena as high-temperature superconductivity and protein folding. Optical Techniques for Solid-State Materials Characterization provides