This text on precision frequency measurement and its key enabling techniques includes reviews written by some of the most experienced researchers in their respective fields. This text should prove useful to researchers just entering the field of frequency metrology and standards, or equally well to the experienced practitioner.

Periodical phenomena or, more precisely, quasiperiodical phenomena, occupy a central position in physics. For a long time, their most important parameter has been their period. However, nowadays, we are much more interested in their frequency, and the many reasons for this are discussed in this book. Throughout history, evaluations of time have been based on periodical phenomena such as the apparent motion of the Sun. Indeed, the oldest unit of time is the day. The apparent motion of the Moon and of the celestial sphere, including changes in the appearance of the former, provided longer units, namely, week, month and year. All these periodical phenomen- the natural clocks - were obviously well suited to the observation and prediction of the evolution of nature with its seasonal rhythm. The gnomon and the clepsydra gave reasonably precise subdivisions of the day that could be used in timing human activities, so long as they were mostly agricultural. The invention of the pendulum and of balance wheel clocks marked the dawn of industrial civilisation, which soon de manded measurements of time with ever increasing precision over shorter and shorter periods.

Modern quantum measurement for graduate students and researchers in quantum information, quantum metrology, quantum control and related fields.

Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency. This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards from atomic clocks, to frequency stabilised lasers. The whole is rounded of with a discussion of topical applications in engineering, telecommunications, and metrology.

This book is focused on the development of Phasor Measurement Units (PMUs) as a tool to analyse and control power systems. The book develops a nonlinear system-wide approach to control using PMU signals and provides numerous examples of different power systems to demonstrate the robustness of the approach in comparison to heuristic optimization. Some of the applicable controls include: · Excitation systems;· Wind power;· Static VAR compensators;· High evoltage DC; and· Inverter dynamics. For the operation of transmission and distribution systems, the book explains the dynamics of power systems and explores how well-established tools such as energy-based control and Kalman filters can address many of the existing and developing issues in their operation. By providing a thorough guide to PMUs, this book enables readers to fully understand the potential benefits their implementation can bring.

In this fascinating book Masatoshi Kajita recounts the importance of precise measurements and their inherent uncertainty, before telling the story of humankind's efforts to define and measure time with increasing accuracy, culminating in the development of atomic clocks. These improvements in the accurate measurement of time and frequency have played a pivotal role in the development of modern science; including the confirmation of Einstein's Theory of Relativity, and the recent detection of gravity waves. Furthermore, such measurements afforded by atomic clocks and other mechanisms are being used to examine key questions about the very fundamentals of our universe, the possibility of symmetry violation and even testing the idea that there may be variation of the fundamental constants themselves over time.

Foreword by Nobel laureate Professor Theodor W. Hänsch of Ludwig-Maximilians-Universität München Based on the authors’ experimental work over the last 25 years, Laser-Based Measurements for Time and Frequency Domain Applications: A Handbook presents basic concepts, state-of-the-art applications, and future trends in optical, atomic, and molecular physics. It provides all the background information on the main kinds of laser sources and techniques, offers a detailed account of the most recent results obtained for time- and frequency-domain applications of lasers, and develops the theoretical framework necessary for understanding the experimental applications. After a historical introduction, the book describes the basic concepts and mathematical tools required for studying the physics of oscillators. It then discusses microwave and optical resonators, crucial aspects of operation and fundamental properties of lasers, and precision spectroscopy and absolute frequency metrology. It also focuses on microwave and optical frequency standards and explores current and potential research directions. Accessible to scientists, postdoc researchers, and advanced undergraduate students, this self-contained book gives a wide-ranging, balanced overview of the areas—including frequency standards and clocks, ultra-high-precision spectroscopy, quantum information, and environmental metrology—revolutionized by the recent advent of optical frequency comb synthesizers (OFCSs) based on femtosecond mode-locked lasers. The book is also a useful guide to cutting-edge research for manufacturers of advanced laser systems and optical devices.

The document is a tutorial Monograph describing various aspects of time and frequency (T/F). Included are chapters relating to elemental concepts of precise time and frequency; basic principles of quartz oscillators and atomic frequency standards; historical review, recent progress, and current status of atomic frequency standards; promising areas for developing future primary frequency standards; relevance of frequency standards to other areas of metrology including a unified standard concept; statistics of T/F data analysis coupled with the theory and construction of the NBS atomic time scale; an overview of T/F dissemination techniques; and the standards of T/F in the USA. The Monograph addresses both the specialist in the field as well as those desiring basic information about time and frequency. The authors trace the development and scope of T/F technology, its improvement over periods of decades, its status today, and its possible use, applications, and development in days to come.

A unique insight into the measurement of time and its applications, at an introductory level.