Optical Frequency Standards: Hertz-Level Working Standards and Their Absolute Frequency Measurement


Book Description

Promising optical frequency/wavelength standards in the visible based on neutral atoms and precise laser sources are studied. In particular we have developed high accuracy systems using diode-lasers with calcium atoms and also diode-pumped Yag-lasers with Iodine molecules. An actual frequency measurement of the Iodine transition at 532 nm is made with the frequency doubled Yag system. On the calcium transition at 657 nm in the red, optical Ramsey-fringes as narrow as 10 kHz have been observed with a high signal-to-noise ratio using diode lasers. High resolution multi-photon spectroscopy on laser cooled and trapped atoms (Na and Cs) have also been explored. In these pursuits, significant new diode-laser and frequency- measurement technology has been developed, including; highly stabilized diode and Yag lasers, the ability to coherently measure the frequency difference between two lasers to as high as approx. 700GHz, and the extension of the spectral coverage of diode laser sources to the blue (for laser cooling of calcium) and IR spectral regions by using nonlinear optical techniques. jg.




Frequency Standards


Book Description

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.




Frequency Standards and Metrology


Book Description

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.




Frequency Standards And Metrology - Proceedings Of The Fifth Symposium


Book Description

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.




Frequency Measurement and Control


Book Description

With contributions by numerous experts




Frequency Standards and Metrology - Proceedings of the 7Th Symposium


Book Description

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 Universit(r) 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 5OCo11, 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."




Femtosecond Optical Frequency Comb: Principle, Operation and Applications


Book Description

Over the last few years, there has been a convergence between the fields of ultrafast science, nonlinear optics, optical frequency metrology, and precision laser spectroscopy. These fields have been developing largely independently since the birth of the laser, reaching remarkable levels of performance. On the ultrafast frontier, pulses of only a few cycles long have been produced, while in optical spectroscopy, the precision and resolution have reached one part in Although these two achievements appear to be completely disconnected, advances in nonlinear optics provided the essential link between them. The resulting convergence has enabled unprecedented advances in the control of the electric field of the pulses produced by femtosecond mode-locked lasers. The corresponding spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as “femtosecond comb technology. ” They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. The historical background for these developments is provided in the Foreword by two of the pioneers of laser spectroscopy, John Hall and Theodor Hänsch. Indeed the developments described in this book were foreshadowed by Hänsch’s early work in the 1970s when he used picosecond pulses to demonstrate the connection between the time and frequency domains in laser spectroscopy. This work complemented the advances in precision laser stabilization developed by Hall.




Frequency Standards And Metrology, Procs Of The 6th Symposium


Book Description

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.







Frequency Standards and Metrology


Book Description

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.