In the never-ending quest for miniaturization, optically controlled particle trapping has opened up new possibilities for handling microscopic matter non-invasively. This thesis presents the application of photorefractive crystals as active substrate materials for optoelectronic tweezers. In these tweezers, flexible optical patterns are transformed into electrical forces by a photoconductive material, making it possible to handle matter with very high forces and high throughput. Potential substrate materials’ properties are investigated and ways to tune their figures-of-merit are demonstrated. A large part of the thesis is devoted to potential applications in the field of optofluidics, where photorefractive optoelectronic tweezers are used to trap, sort and guide droplets or particles in microfluidic channels, or to shape liquid polymers into optical elements prior to their solidification. Furthermore, a new surface discharge model is employed to discuss the experimental conditions needed for photorefractive optoelectronic tweezers.

Research and development in modern optical and photonic technologies have witnessed quite fast growing advancements in various fundamental and application areas due to availability of novel fabrication and measurement techniques, advanced numerical simulation tools and methods, as well as due to the increasing practical demands. The recent advancements have also been accompanied by the appearance of various interdisciplinary topics. The book attempts to put together state-of-the-art research and development in optical and photonic technologies. It consists of 21 chapters that focus on interesting four topics of photonic crystals (first 5 chapters), THz techniques and applications (next 7 chapters), nanoscale optical techniques and applications (next 5 chapters), and optical trapping and manipulation (last 4 chapters), in which a fundamental theory, numerical simulation techniques, measurement techniques and methods, and various application examples are considered. This book deals with recent and advanced research results and comprehensive reviews on optical and photonic technologies covering the aforementioned topics. I believe that the advanced techniques and research described here may also be applicable to other contemporary research areas in optical and photonic technologies. Thus, I hope the readers will be inspired to start or to improve further their own research and technologies and to expand potential applications. I would like to express my sincere gratitude to all the authors for their outstanding contributions to this book.

Structured singular light is an ubiquitous phenomenon. It is not only created when light refracts at a water surface but can also be found in the blue daytime sky. Such light fields include a spatially varying amplitude, phase, or polarization, enabling the occurrence of optical singularities. As structurally stable units of the light field, these singularities are particularly interesting since they determine its topology. In this excellent book, the author presents a pioneering study of structured singular light, thereby contributing many original approaches. Especially in the field of polarization and its rich number of different types of singularities the book defines and drives a completely new field. The work demonstrates how to control complex polarization singularity networks and their propagation. Additionally, the author pioneers tightly focusing vectorial beams, also developing an urgently needed detection scheme for three-dimensional nanoscale polarization structures. She also studies classical spatial entanglement using structured light, introducing entanglement beating and paraxial spin-orbit-coupling. The book is hallmarked by its comprehensive and thorough way of describing a plethora of different approaches to structure light by amplitude, phase and polarization, as well as the important role of optical singularities.

This detailed volume explores a wide variety of techniques involving optical tweezers, a technology that has become increasingly more accessible to a broad range of researchers. Beginning with recent technical advances, the book continues by covering the application of optical tweezers to study DNA-protein interactions and DNA motors, protocols to perform protein (un)folding experiments, the application of optical tweezers to study actin- and microtubule-associated motor proteins, and well as protocols for investigating the function and mechanical properties of microtubules and intermediate filaments, and more. Written for the highly successful Methods in Molecular Biology series, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Optical Tweezers: Methods and Protocols, Second Edition serves as an ideal resource for expanding the accessibility and use of optical traps by scientists of diverse disciplines.