Download or read book X ray waveguide optics written by Sarah Hoffmann-Urlaub and published by Göttingen University Press. This book was released on 2017 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern x-ray sources and analysis techniques such as lens less imaging combined with phase retrieval algorithms allow for resolving structure sizes in the nanometer range. For this purpose optics have to be employed, ensuring small focal spot dimensions simultaneously with high photon densities. Furthermore, the wave front behind the optics is required to be smooth enabling for high resolution imaging. Combining all these properties, x-ray waveguides are well suited to perform this task, since the intensity distribution behind the guide is restricted in two dimensions serving as a secondary quasi point-source without wave-front aberrations, showing also a high divergence, suitable for resolving fine features. Importantly, the radiation provided by the waveguide reveals a high degree of coherence, required by many imaging techniques. The waveguide itself consists of an air-filled channel embedded in a solid matrix; typical materials are silicon, germanium or quartz. While the entrance area is nano-sized, the channel length is in the millimeter-range, this way posing challenges to fabricate high aspect ratio geometries. Since the functioning of x-ray waveguides is based on the total reflection at small incident angles, the surface roughness of the channel walls must be as low as possible to avoid scattering and hence loss of intensity. To fulfill these demanding conditions, a process scheme involving spin-coating, electron beam lithography, wet development, reactive ion etching and wafer bonding is optimized within this work. To gain deeper insights into the principle of wave guiding finite difference simulations are performed, also opening access for advanced design considerations such as gratings, tapered and curved channels, or beamsplitters, enabling for constructing novel x-ray tools as for example time delay devices or interferometers. Waveguides in all geometries are tested at synchrotron sources, accomplishing new benchmarks in x-ray optical performance. Here, the x-ray beam leaving the channel, propagates out to a pixel array detector in the far-field region. From the recorded data the intensity distribution in the near-field directly behind the waveguide is reconstructed, revealing an outstanding agreement with the simulations and electron micrographs. Since the radiation field of the waveguide is well-characterized and also tunable to meet the requirements of both the measurement setup and the sample, they are suited of a broad field of applications in coherent x-ray imaging.

Download or read book X ray Waveguide Optics Beyond Straight Channels written by Sarah Hoffmann-Urlaub and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern x-ray sources and analysis techniques such as lens less imaging combined with phase retrieval algorithms allow for resolving structure sizes in the nanometerrange. For this purpose optics have to be employed, ensuring small focal spot dimensions simultaneously with high photon densities. Furthermore, the wave front behind the optics is required to be smooth enabling for high-resolution imaging. Combining all these properties, x-ray waveguides are well suited to perform this task, since the intensity distribution behind the guide is restricted in two dimensions serving as a secondary ...

Download or read book Optimization of Waveguide Optics for Lensless X ray Imaging written by Sven Philip Krüger and published by Universitätsverlag Göttingen. This book was released on 2011 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lensless x-ray imaging is a promising method to determine the three-dimensional structure of material science and biological specimens at the nanoscale. The development of this technique is strongly related to the optimization of x-ray optics since the image formation and object reconstruction depend significantly on the properties of the illumination wave-field. Waveguide optics act as quasi-point sources and enable the spatial and coherent filtering of x-ray beams. Up to now, x-ray waveguides were severely limited in transmission and flux, restricting their use to high-contrast test structures with moderate resolution and long accumulation times. To overcome these limitations, a novel waveguide design with an optimized refractive index profile is presented which significantly minimizes the absorption of the modes propagating inside the waveguide. Experimental results along with simulations show that these two-component planar x-ray waveguides provide small beam cross-sections along with a high photon flux at the exit. By a serial arrangement of two waveguide slices an optimized illumination source has been developed for high-resolution microscopy, as demonstrated in proof-of-concept imaging experiments.

Download or read book A Dedicated Endstation for Waveguide based X ray Imaging written by Sebastian Kalbfleisch and published by Universitätsverlag Göttingen. This book was released on 2013 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced X ray Multilayer Waveguide Optics written by Qi Zhong and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this thesis is to demonstrate that x-ray waveguide optics can be gen- eralized from a single guiding film to an array of planar waveguides, enabling more complex and controllable phenomena of field propagation both in partic- ular in the near-field in the vicinity of objects to be probed by coherent imaging. Two advanced x-ray multilayer waveguides (MWGs) structures, i.e. the waveg- uide array (WGA) and the multi-guide resonant beam couplers (RBCs) are de- signed and discussed. Starting from basic theoretical analysis, the structural model of MWGs is built up. Then the MWGs are s...

Download or read book Advanced x ray multilayer waveguide optics written by Qi Zhong and published by Göttingen University Press. This book was released on 2017 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this thesis was to design novel waveguide structures, and to analyze them in view of complex phenomena of near-field propagation. For this purpose, experimental far-field measurements were used in combination with finite-difference simulations and phase retrieval methods. Two novel structures have been designed, fabricated and characterized: the waveguide array (WGA), yielding several waveguided beams in transmission, and multi-guide resonate beam couplers (RBCs), tailored to yield two or several reflected beams. Two novel structures have been designed, fabricated and characterized: the WGA, yielding several waveguided beams in transmission, and multi-guide RBCs, tailored to yield two or several reflected beams. The WGA and the multi-guide RBCs are not only distinct in the coupling geometry. A major difference is related to the fact that the WGA principle is based on the separation (non coupling) of the different transmitted wavelets, while the RBC functions are based on a strong coupling of guided radiation in several layers.

Download or read book Wave Optical Simulations of X ray Nano focusing Optics written by Markus Osterhoff and published by Universitätsverlag Göttingen. This book was released on 2012 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Curved x-ray multilayer mirrors focus synchrotron beams down to tens of nano metres. A wave-optical theory describing propagation of two waves in an elliptically curved focusing multilayer mirror is developed in this thesis. Using numerical integration, the layer shapes can be optimised for reflectivity and aberrations. Within this framework, performance of both existing and currently upgraded synchrotron beamlines is simulated. Using a more theoretical model case, limits of the theory are studied. A significant part of this work is dedicated to partial spatial coherence, modelled using the method of stochastic superpositions. Coherence propagation and filtering by x-ray waveguides is shown analytically and numerically. This comprehensive model is put forward that shall help in development and testing of new algorithms for a variety of imaging techniques using coherent x-ray beams. Advanced simulations accounting for real structure effects are compared to experimental data obtained at the GINIX instrument at the coherence beamline P10 at PETRA III, DESY. This thesis presents results of a collaboration between the Georg-August-Universität Göttingen and the European Synchrotron Radiation Facility (ESRF) Grenoble.

Download or read book Soft X ray Optics written by Eberhard Spiller and published by SPIE Press. This book was released on 1994 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction. Some of these structures can now be fabricated to have diffraction-limited resolution. The new possibilities are described in a simple, tutorial way.

Download or read book Modern Developments in X Ray and Neutron Optics written by Alexei Erko and published by Springer. This book was released on 2008-04-01 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume describes modern developments in reflective, refractive and diffractive optics for short wavelength radiation. It also covers recent theoretical approaches to modelling and ray-tracing the x-ray and neutron optical systems. It is based on the joint research activities of specialists in x-ray and neutron optics, working together under the framework of the European Programme for Cooperation in Science and Technology (COST, Action P7) in the period 2002-2006.

Download or read book Hard X ray Waveguide Optics written by Ansgar Jarre and published by . This book was released on 2005 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoscale Photonic Imaging written by Tim Salditt and published by Springer Nature. This book was released on 2020-06-09 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book, edited and authored by a team of world-leading researchers, provides a broad overview of advanced photonic methods for nanoscale visualization, as well as describing a range of fascinating in-depth studies. Introductory chapters cover the most relevant physics and basic methods that young researchers need to master in order to work effectively in the field of nanoscale photonic imaging, from physical first principles, to instrumentation, to mathematical foundations of imaging and data analysis. Subsequent chapters demonstrate how these cutting edge methods are applied to a variety of systems, including complex fluids and biomolecular systems, for visualizing their structure and dynamics, in space and on timescales extending over many orders of magnitude down to the femtosecond range. Progress in nanoscale photonic imaging in Göttingen has been the sum total of more than a decade of work by a wide range of scientists and mathematicians across disciplines, working together in a vibrant collaboration of a kind rarely matched. This volume presents the highlights of their research achievements and serves as a record of the unique and remarkable constellation of contributors, as well as looking ahead at the future prospects in this field. It will serve not only as a useful reference for experienced researchers but also as a valuable point of entry for newcomers.

Download or read book X ray Waveguides for High Resolution X ray Analysis written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The project goals were to model, synthesize, and characterize thin-film, x-ray waveguide structures to determine whether such nanostructurcs can be fabricated with the precision required for true waveguide operation at x-ray energies. In FY98, we designed, fabricated, and characterized (at the Stanford Synchrotron Radiation Laboratory) optimized. thin-film, x-ray waveguide structures (XWGs) as resonant concentrators of x-rays which may be applied as diffraction-limited, linear x-ray sources. We fabricated nine waveguide structures that were optimized to operate in the cavity modes m = 1,2,3 and tested them at x-ray energies of 6 to 10 keV. The observed performances were compared to the calculations based on the design structures and excellent agreement was demonstrated. This project plan is presented in TABLE 1 that includes all aspects of the development of these unique thin film x-ray optical devices. X-ray waveguide designs were made using a standard x-ray multilayer x-ray optic Fresnel code. Materials were selected on the basis of calculated performance as well as sputter deposition characteristics. Laboratory x-ray reflectivity measurements were made prior to the SSRL experimental run to assess the quality of the samples. Cross-section Transmission Electron Microscopy observations of selected sample were made to enable assessment of the relationship between the design structures and the fabricated structures. The cross-section TEM observations correlated well with the waveguide fabrication parameters supporting the observed agreement between the experimental and calculated grazing incidence reflectivities and fluorescence as functions of both x-ray energy and grazing angle of incidence.

Download or read book Optical Waveguides written by María L. Calvo and published by CRC Press. This book was released on 2018-10-03 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the theory and principles of optical waveguides have been established for more than a century, the technologies have only been realized in recent decades. Optical Waveguides: From Theory to Applied Technologies combines the most relevant aspects of waveguide theory with the study of current detailed waveguiding technologies, in particular, photonic devices, telecommunication applications, and biomedical optics. With self-contained chapters written by well-known specialists, the book features both fundamentals and applications. The first three chapters examine the theoretical foundations and bases of planar optical waveguides as well as critical optical properties such as birefringence and nonlinear optical phenomena. The next several chapters focus on contemporary waveguiding technologies that include photonic devices and telecommunications. The book concludes with discussions on additional technological applications, including biomedical optical waveguides and the potential of neutron waveguides. As optical waveguides play an increasing part in modern technology, photonics will become to the 21st century what electronics were to the 20th century. Offering both novel insights for experienced professionals and introductory material for novices, this book facilitates a better understanding of the new information era—the photonics century.

Download or read book Electromagnetic Propagation and Waveguides in Photonics and Microwave Engineering written by Patrick Steglich and published by BoD – Books on Demand. This book was released on 2020-10-21 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical and microwave waveguides have attracted much research interest in both science and industry. The number of potential applications for their use is growing rapidly. This book examines recent advances in the broad field of waveguide technology. It covers current progress and latest breakthroughs in emergent applications in photonics and microwave engineering. The book includes ten contributions on recent developments in waveguide technologies including theory, simulation, and fabrication of novel waveguide concepts as well as reviews on recent advances.

Download or read book Optical Waveguide Theory written by A.W. Snyder and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text is intended to provide an in-depth, self-contained, treatment of optical waveguide theory. We have attempted to emphasize the underlying physical processes, stressing conceptual aspects, and have developed the mathematical analysis to parallel the physical intuition. We also provide comprehensive supplementary sections both to augment any deficiencies in mathematical background and to provide a self-consistent and rigorous mathematical approach. To assist in. understanding, each chapter con centrates principally on a single idea and is therefore comparatively short. Furthermore, over 150 problems with complete solutions are given to demonstrate applications of the theory. Accordingly, through simplicity of approach and numerous examples, this book is accessible to undergraduates. Many fundamental topics are presented here for the first time, but, more importantly, the material is brought together to give a unified treatment of basic ideas using the simplest approach possible. To achieve such a goal required a maturation of the subject, and thus the text was intentionally developed over a protracted period of the last 10 years.

Download or read book Advances in X ray Optics written by Andreas K. Freund and published by SPIE-International Society for Optical Engineering. This book was released on 2001 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Optical Waveguides written by Katsunari Okamoto and published by Elsevier. This book was released on 2010-08-04 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Optical Waveguides is an essential resource for any researcher, professional or student involved in optics and communications engineering. Any reader interested in designing or actively working with optical devices must have a firm grasp of the principles of lightwave propagation. Katsunari Okamoto has presented this difficult technology clearly and concisely with several illustrations and equations. Optical theory encompassed in this reference includes coupled mode theory, nonlinear optical effects, finite element method, beam propagation method, staircase concatenation method, along with several central theorems and formulas. Since the publication of the well-received first edition of this book, planar lightwave circuits and photonic crystal fibers have fully matured. With this second edition the advances of these fibers along with other improvements on existing optical technologies are completely detailed. This comprehensive volume enables readers to fully analyze, design and simulate optical atmospheres. Exceptional new chapter on Arrayed-Waveguide Grating (AWG) In-depth discussion of Photonic Crystal Fibers (PCFs) Thorough explanation of Multimode Interference Devices (MMI) Full coverage of polarization Mode Dispersion (PMD)