Demonstration of a Transportable 1 Hz-Linewidth Laser

We present the setup and test of a transportable clock laser at 698 nm for a strontium lattice clock. A master-slave diode laser system is stabilized to a rigidly mounted optical reference cavity. The setup was transported by truck over 400 km from Braunschweig to D\"usseldorf, where the cavity-stabilized laser was compared to a stationary clock laser for the interrogation of ytterbium (578 nm). Only minor realignments were necessary after the transport. The lasers were compared by a Ti:Sapphire frequency comb used as a transfer oscillator. The thus generated virtual beat showed a combined linewidth below 1 Hz (at 1156 nm). The transport back to Braunschweig did not degrade the laser performance, as was shown by interrogating the strontium clock transition.Comment: 3 pages, 4 figure

Служение Государству – Новая Социально-Ценностная Ориентация Подготовки Будущих Чиновников

The article analyzes the processes caused by the change of social and value meanings of life and the person himself, based on two all-Russian sociological studies of professional education conducted at the beginning of this century and the conditions that allow implementing a new social and value orientation in the training of future officials-service to the state. The purpose of the study: to determine the factors, models and conditions for the formation of a new paradigm in training in the direction of "State and municipal management". The basis of the study: a systematic approach that provided to identify the conditions under which service to the state can become a new social and value orientation in the training of future state and municipal employees. The comparative legal method made it possible to analyze the state policy in this area. Results: the factors that destroy the social-value orientation of young people – the change in values education; dehumanization of relationships in society; decline in status of the family; the formula changing behavior of young people; change the orientation to individualism; departure from civil and Patriotic education. The conditions that determine the success of the new socio-value orientation in the training of future officials-service to the state are defined as follows: state policy in this area of education; the model of behavior of officials of the new formation based on the recognition of social values; pedagogical tools of the educational component of the socio-pedagogical function of higher education; orientation to the professionalization and socialization of future officials; education of a citizen and patriot of their country, able to implement effectively and efficiently the goals and functions of the state. It is proved that the model of social-personal and social-value competencies of graduates in this specialty should be strategically justified and contain a civil-Patriotic component. © Т.М. Резер, Г.А. Невски

Optical Clocks in Space

The performance of optical clocks has strongly progressed in recent years, and accuracies and instabilities of 1 part in 10^18 are expected in the near future. The operation of optical clocks in space provides new scientific and technological opportunities. In particular, an earth-orbiting satellite containing an ensemble of optical clocks would allow a precision measurement of the gravitational redshift, navigation with improved precision, mapping of the earth's gravitational potential by relativistic geodesy, and comparisons between ground clocks.Comment: Proc. III International Conference on Particle and Fundamental Physics in Space (SpacePart06), Beijing 19 - 21 April 2006, to appear in Nucl. Phys.

Экспериментальная и аналитическая оценка передаточных свойств металлической решетки миллиметрового диапазона

Metal gratings (MGs) with rectangular lamels based on the technology of jet etching of thin metal plates are widely used in different polarization devices of microwave and terahertz engineering. Numerical methods of mathematical modeling or direct measurements are employed for their analysis. Sometimes in case of H-polarization, analytical approaches for evaluation of transmission characteristics of such gratings can be taken. However, the accuracy of the most of proposed similar models depends essentially upon sizes and frequency ranges. The present article provides both theoretical and experimental research of transmission characteristics of MG with fixed size illuminated by plane electromagnetic wave with H-polarization. Two analytical models are utilized for preliminary evaluation of MG parameters. One of them determines the top limit of T(f) variations, where T is transmittance and f is frequency. The other model determines the bottom limit. The given models were implemented in assumption of small reflections in microwave network. MG size defines one of the restrictions on their application.Для расчета передаточных характеристик металлических решеток с прямоугольными перемычками предложены две аналитические модели, базирующиеся на теории распространения электромагнитных волн в микроволновых многополюсниках с неоднородностями. Результаты теоретических расчетов в диапазоне 110...170 ГГц сравниваются с данными экспериментальных исследований стальной решетки с периодом 100 мкм

Active laser frequency stabilization using neutral praseodymium (Pr)

We present a new possibility for the active frequency stabilization of a laser using transitions in neutral praseodymium. Because of its five outer electrons, this element shows a high density of energy levels leading to an extremely line-rich excitation spectrum with more than 25000 known spectral lines ranging from the UV to the infrared. We demonstrate the active frequency stabilization of a diode laser on several praseodymium lines between 1105 and 1123 nm. The excitation signals were recorded in a hollow cathode lamp and observed via laser-induced fluorescence. These signals are strong enough to lock the diode laser onto most of the lines by using standard laser locking techniques. In this way, the frequency drifts of the unlocked laser of more than 30 MHz/h were eliminated and the laser frequency stabilized to within 1.4(1) MHz for averaging times >0.2 s. Frequency quadrupling the stabilized diode laser can produce frequency-stable UV-light in the range from 276 to 281 nm. In particular, using a strong hyperfine component of the praseodymium excitation line E = 16 502.616_7/2 cm^-1 -> E' = 25 442.742_9/2 cm^-1 at lambda = 1118.5397(4) nm makes it possible - after frequency quadruplication - to produce laser radiation at lambda/4 = 279.6349(1) nm, which can be used to excite the D2 line in Mg^+.Comment: 10 pages, 14 figure

A New Option for a Search for Alpha Variation: Narrow Transitions with Enhanced Sensitivity

We consider several transitions between narrow lines that have an enhanced sensitivity to a possible variation of the fine structure constant, alpha. This enhancement may allow a search to be performed with an effective suppression of the systematic sources of uncertainty that are unavoidable in conventional high-resolution spectroscopic measurements. In the future this may provide the strongest laboratory constraints on alpha variation

Ultra-precise measurement of optical frequency ratios

We developed a novel technique for frequency measurement and synthesis, based on the operation of a femtosecond comb generator as transfer oscillator. The technique can be used to measure frequency ratios of any optical signals throughout the visible and near-infrared part of the spectrum. Relative uncertainties of $10^{-18}$ for averaging times of 100 s are possible. Using a Nd:YAG laser in combination with a nonlinear crystal we measured the frequency ratio of the second harmonic $\nu_{SH}$ at 532 nm to the fundamental $\nu_0$ at 1064 nm, $\nu_{SH}/\nu_0 = 2.000 000 000 000 000 001 \times (1 \pm 7 \times 10^{-19})$.Comment: 4 pages, 4 figure

The Space Optical Clocks Project: Development of high-performance transportable and breadboard optical clocks and advanced subsystems

The use of ultra-precise optical clocks in space ("master clocks") will allow for a range of new applications in the fields of fundamental physics (tests of Einstein's theory of General Relativity, time and frequency metrology by means of the comparison of distant terrestrial clocks), geophysics (mapping of the gravitational potential of Earth), and astronomy (providing local oscillators for radio ranging and interferometry in space). Within the ELIPS-3 program of ESA, the "Space Optical Clocks" (SOC) project aims to install and to operate an optical lattice clock on the ISS towards the end of this decade, as a natural follow-on to the ACES mission, improving its performance by at least one order of magnitude. The payload is planned to include an optical lattice clock, as well as a frequency comb, a microwave link, and an optical link for comparisons of the ISS clock with ground clocks located in several countries and continents. Undertaking a necessary step towards optical clocks in space, the EU-FP7-SPACE-2010-1 project no. 263500 (SOC2) (2011-2015) aims at two "engineering confidence", accurate transportable lattice optical clock demonstrators having relative frequency instability below 1\times10^-15 at 1 s integration time and relative inaccuracy below 5\times10^-17. This goal performance is about 2 and 1 orders better in instability and inaccuracy, respectively, than today's best transportable clocks. The devices will be based on trapped neutral ytterbium and strontium atoms. One device will be a breadboard. The two systems will be validated in laboratory environments and their performance will be established by comparison with laboratory optical clocks and primary frequency standards. In this paper we present the project and the results achieved during the first year.Comment: Contribution to European Frequency and Time Forum 2012, Gothenburg, Swede