This book discusses the latest research ideas with application to frequency standards (e.g. optical clocks) and assesses ideas from previous symposia which have undergone critical analysis.

The Symposium on Frequency Standards and Metrology is an event held approximately every seven years, and is regarded as the premier conference in the field of advanced clocks and oscillators together with their applications in science and metrology. This series began with the first meeting at Universiteacute; Laval, Quebec Canada in 1971, and the last one was held in 2001 at the University of St. Andrews, Scotland. The 7th Symposium on Frequency Standards and Metrology is scheduled for October 5ndash;11, 2008 at the Asilomar Conference Grounds in Pacific Grove, California, USA. The Symposium is intended as a forum for bringing together international scientists and technologists engaged in the development of precise frequency standards and clocks, the study of their underlying physics, and their applications in metrology and tests of fundamental laws. The symposium has been traditionally held in a venue that promotes exchange of information on emerging ideas and latest achievements in the field, with a single-session approach which includes oral presentations by invitation, poster session(s) and keynote talks from internationally-recognized speakers. The program also includes social and other events aimed at promoting the exchange of technical and scientific information.

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.

Since the previous Symposium, several exciting new developments and advances have occurred in the field of frequency standards and metrology. These include the first results on the long-tenn stability of a millisecond Pulsar, for which data 14 integrated over several years now show a stability of around 10- . Improvements in the understanding of various biases in Cesium beam standards promise accuracies in the low 14s for primary standards and in the low 13s for short commercial tubes, for which long tenn stabilities in low 14s have already been shown to be obtainable by accuracy improvement. Beams using optical pumping for state selection and for detection have been operated with excellent results, and more are being realized. Other new frequency standards which have appeared include a macroscopic rf trap with Mercury ions, which perfonns in the low 15s in one day, the sub millimeter metastable Magnesium beam, which has shown a short tenn stability 19 in the low 12s in one second and promises an accuracy of 10- , and the cold Hydrogen masers, which have such high stabilities that they cannot be measured with existing local oscillators. Prospects for future developments include laser manipulation of neutrals and spectroscopy of single ions at rest in a trap. Both these groups of techniques have great potential for unprecedented accuracy and short-and long-tenn stability, and new superior frequency standards are expected to be realizable in this way in the not too distant future.

The Symposium on Frequency Standards and Metrology serves as an international forum for discussion of precision frequency standards throughout the electromagnetic spectrum and associated metrology. The symposium focuses on the fundamental aspects of the latest ideas, results and applications in relation to these frequency standards.

This book discusses the latest research ideas with application to frequency standards (e.g. optical clocks) and assesses ideas from previous symposia which have undergone critical analysis.

This volume covers advances in atomic frequency standards (atomic clocks) from the last several decades. It explains the use of techniques, such as laser optical pumping, coherent population trapping, laser cooling, and electromagnetic and optical trapping, in the implementation of classical microwave and optical atomic frequency standards. The authors describe the basic physics behind the operation of atomic clocks, explore new frequency standards that provide better stability and accuracy than conventional standards, and illustrate the application of atomic clocks in various areas.

Metrology is a constantly evolving field, and one which has developed in many ways in the last four decades. This book presents the proceedings of the Enrico Fermi Summer School on the topic of Metrology, held in Varenna, Italy, from 26 June to 6 July 2017. This was the 6th Enrico Fermi summer school devoted to metrology, the first having been held in 1976. The 2017 program addressed two major new directions for metrology: the work done in preparation for a possible re-definition of four of the base units of the SI in 2018, and the impact of the application of metrology to issues addressing quality of life – such as global climate change and clinical and food analysis – on science, citizens and society. The lectures were grouped into three modules: metrology for quality of life; fundamentals of metrology; and physical metrology and fundamental constants, and topics covered included food supply and safety; biomarkers; monitoring climate and air quality; new IS units; measurement uncertainty; fundamental constants; electrical metrology; optical frequency standards; and photometry and light metrology. The book provides an overview of the topics and changes relevant to metrology today, and will be of interest to both academics and all those whose work involves any of the various aspects of this field.

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.