Due to the development of microscale fabrication methods, microlenses are being used more and more in many unique applications, such as artificial implementations of compound eyes, optical communications, and labs-on-chips. Liquid microlenses, in particular, represent an important and growing research area yet there are no books devoted to this top

This book is a printed edition of the Special Issue "Microlenses" that was published in Micromachines

The general trend towards miniaturisation and parallelism in optics and electro-optics has led to a requirement for arrays of sub-millimetre sized lenses. Thus, the demand for these microlens arrays has increased dramatically over recent years. Dan Daly's book describes the technology of microlens arrays and provides a recipe for producing them. It surveys the many fabrication techniques and discusses the numerous applications which either require or enhanced by the use of microlens arrays. This book gives a full description of the processes involved in production and limitations of the techniques. Processes looked at include the Thermal Reflow of Photoresist technique and the Silicon Elastomer Replication Process. As the measurement of microlenses is an intrinsic part of the production process, the methods which can be used to evaluate lens performance are explained.

Due to the development of microscale fabrication methods, microlenses are being used more and more in many unique applications, such as artificial implementations of compound eyes, optical communications, and labs-on-chips. Liquid microlenses, in particular, represent an important and growing research area yet there are no books devoted to this topic that summarize the research to date. Rectifying this deficiency, Microlenses: Properties, Fabrication and Liquid Lenses examines the recent progress in the emerging field of liquid-based microlenses. After describing how certain problems in optics can be solved by liquid microlenses, the book introduces the physics and fabrication methods involved in microlenses. It also details the facility and equipment requirements for general fabrication methods. The authors then present examples of various microlenses with non-tunable and tunable focal lengths based on different mechanisms, including: Non-tunable microlenses: Ge/SiO2 core/shell nanolenses, glass lenses made by isotropic etching, self-assembled lenses and lens arrays, lenses fabricated by direct photo-induced polymerization, lenses formed by thermally reflowing photoresist, lenses formed from inkjet printing, arrays fabricated through molding processes, and injection-molded plastic lenses Electrically tuned microlenses: liquid crystal-based lenses and liquid lenses driven by electrostatic forces, dielectrophoretic forces, electrowetting, and electrochemical reactions Mechanically tunable microlenses: thin-membrane lenses with varying apertures, pressures, and surface shapes; swellable hydrogel lenses; liquid–liquid interface lenses actuated by environmentally stimuli-responsive hydrogels; and oscillating lens arrays driven by sound waves Horizontal microlenses: two-dimensional polymer lenses, tunable and movable liquid droplets as lenses, hydrodynamically tuned cylindrical lenses, liquid core and liquid cladding lenses, air–liquid interface lenses, and tunable liquid gradient refractive index lenses The book concludes by summarizing the importance of microlenses, shedding light on future microlens work, and exploring related challenges, such as the packaging of systems, effects of gravity, evaporation of liquids, aberrations, and integration with other optical components.

The resonator can be considered the real heart of any laser system, the key element that determines the properties of laser radiation, including mode structure or temporal and spatial characteristics. The theory of different laser types has been well-developed in the last few decades of the 20th century, starting with the pioneering papers of Fox, Li, Body and Gordon. But today, due to the development of new types of lasers (fibre, diode), new optical elements (adaptive mirrors, phase conjugation techniques, graded phase correctors), the development of optical technology, and new needs for industrial lasers, novel types of resonators are under investigation.

This book presents a comprehensive account of the recent advances and research in optical fiber technology. It covers a broad spectrum of topics in special areas of optical fiber technology. The book highlights the development of fiber lasers, optical fiber applications in medical, imaging, spectroscopy and measurement, new optical fibers and sensors. This is an essential reference for researchers working in optical fiber researches and for industrial users who need to be aware of current developments in fiber lasers, sensors and other optical fiber applications.