Recent studies indicate that China accounts for about 96 percent of the world’s supply of rare earth materials (REMs). With REMs becoming increasingly important for a growing number of high-tech applications, appropriate action must be taken to mitigate the effects of a shortage of critical REMs in defense systems and components. Bringing together information previously available only from disparate journal articles and databases, Rare Earth Materials: Properties and Applications describes the unique characteristics and applications of 17 REMs. It defines their chemical, electrical, thermal, and optical characteristics. Maintaining a focus on physical and chemical properties, it addresses the history and critical issues pertaining to mining and processing of REMs. In this book, Dr. A.R. Jha continues his distinguished track record of distilling complex theoretical physical concepts into an understandable technical framework that can be extended to practical applications across commercial and industrial frameworks. He summarizes the chemical, optical, electrical, thermal, magnetic, and spectroscopic properties of REMs best suited for next-generation commercial and military systems or equipment. Coverage includes extraction, recycling, refinement, visual inspection, identification of spectroscopic parameters, quality control, element separation based on specific application, pricing control, and environmental / geo-political considerations. Potential applications are identified with an emphasis on scientific instruments, nuclear resonance imaging equipment, MRI systems, magnetic couplers for uranium enrichment equipment, battery-electrodes, electric motors, electric generators, underwater sensors, and commercial and military sensors. The book describes unique applications of rare earth magnets in all-electric and hybrid electric cars and microwave components. It also considers the use of rare earth magnets in commercial and military systems where weight and size are the critical design requirements. Suitable for both students and design engineers involved in the development of high-technology components or systems, the book concludes by summarizing future applications in electro-optic systems and components, including infrared lasers, diode-pumped solid-state lasers operating at room temperatures, and other sophisticated military and commercial test equipment

This book is devoted to the theoretical and experimental investigation of the optoelectronic oscillator (OEO) with direct and external modulation of laser emission. Such devices, sources of precision radio frequency oscillations using laser excitation, are novel and technologically relevant, with manifold possible applications. The book includes a review of the present state of the theory and generation techniques in microwave and mm-wave ranges for traditional and optoelectronic oscillators, description of OEO construction and operation principles, theoretical oscillation analysis and mathematical description of the relevant semi-classical laser physics, and investigation of the power spectral density of noises. Technical features and advantages of OEOs with external and direct modulation of laser emission are discussed together with functional diagrams. The characteristics of OEOs are compared with other traditional RF oscillators, such as quartz, surface acoustic waves, and oscillators with electromagnetic wave cavities. Special attention is paid to Q-factors and phase noises of RF carriers at small offsets. The authors discuss the technical characteristics of modern optoelectronic methods for precision RF oscillation formation, such as commercial large-dimension and compact quantum frequency standards with optical pumping on cesium and rubidium cells. This book is aimed at scientists and engineers in academia and industry who work with sources of microwave and mm-wave signals.

The integration of microelectromechanical systems (MEMS) and nanotechnology (NT) in sensors and devices significantly reduces their weight, size, power consumption, and production costs. These sensors and devices can then play greater roles in defense operations, wireless communication, the diagnosis and treatment of disease, and many more applications. MEMS and Nanotechnology-Based Sensors and Devices for Communications, Medical and Aerospace Applications presents the latest performance parameters and experimental data of state-of-the-art sensors and devices. It describes packaging details, materials and their properties, and fabrication requirements vital for design, development, and testing. Some of the cutting-edge materials covered include quantum dots, nanoparticles, photonic crystals, and carbon nanotubes (CNTs). This comprehensive work encompasses various types of MEMS- and NT-based sensors and devices, such as micropumps, accelerometers, photonic bandgap devices, acoustic sensors, CNT-based transistors, photovoltaic cells, and smart sensors. It also discusses how these sensors and devices are used in a number of applications, including weapons’ health, battlefield monitoring, cancer research, stealth technology, chemical detection, and drug delivery.