Modified quantum frequency standard on Hg-199 ions

The world around us depends on devices capable of producing or maintaining a signal with an extreme precision. Quantum frequency standards are the answer to this problem. This article presents a modified version of newly developed quantum frequency standard based on trapping Hg-199 ions by magnetic field. The new prototype was developed a while ago and now it was modified due to algorithm improvements and renewed digital hardware, analog and digital circuitry being reordered. Results for Allan deviation show 3 % improvement for long-term frequency stability and more than 5 % for short-term stability

SIMULATION OF INSTABILITIES OF QUANTUM FREQUENCY STANDARDS FOR PROBLEMS OF TIME SERVICES AND NAVIGATION

In the article, two models of instability of quantum frequency standards (QFS) are considered. This is a generally accepted stochastic model that describes the effect of noise with different frequencies on the stability of the clock and the simulation model proposed by the authors of this article, based on the Monte Carlo method and a software random number generator. Based on simulation results, a comparative analysis of advantages and disadvantages of the proposed QFS model in comparison with the classical model was carried out. The results of modeling, which showed good convergence with the accepted theoretical assumptions, are presented. The rationale for the feasibility of using the proposed model in the processing of navigation measurements is given. The possibilities of increasing the accuracy of synchronization of remote sets of reference time are shown.

Control algorithms in quantum frequency standards based on the effect of coherent population trapping

The problem of developing control algorithms in quantum frequency standards based on the effect of coherent population trapping is considered. The development of such algorithms will make it possible to create frequency standards with metrological characteristics that are not inferior to the characteristics of rubidium frequency standards, with reduced power consumption and overall dimensions. A method for studying the dependence of the actual value and frequency instability of quantum frequency standards based on the effect of coherent population trapping on the operating modes of individual parts of the standards is presented. As a criterion for optimizing the laser injection current, the output power of the microwave generator, and the cell temperature, we chose to minimize the effect on the shift of the actual frequency of the standard. A comparative analysis of methods for changing the radiation intensity of a surface-emitting laser with a vertical resonator has been carried out and control algorithms have been developed that take into account the features of these methods. Based on these algorithms, software and tuning methods have been developed in quantum frequency standards based on the effect of coherent population trapping. For the prototype standard, the results of measuring the frequency instability are shown. It is shown that control algorithms and tuning methods can qualitatively change the metrological characteristics of quantum frequency standards based on the effect of coherent population trapping.

Thermal compensation in quantum frequency standards based on the effect of coherent population trapping

The problem of developing a thermal compensation system in quantum frequency standards based on the effect of coherent population trapping is considered. The development of such a system significantly reduces the temperature coefficient of frequency, the value of which is an order of magnitude higher than in rubidium frequency standards. One of the ways to reduce the temperature coefficient of frequency is temperature compensation. A method of thermal compensation based on the Zeeman effect for the shift of the actual frequency is proposed. A method for determining the minimum value of the magnetic field at which there is no influence of magnetosensitive resonances on the reference resonance is considered. The results of the operation of the quantum frequency standard before and after switching on the thermal compensation system are presented.

Резонансы когерентного пленения населенностей в стеклянных ячейках с парами атомов цезия, изготовленных методом индукционной сварки

The paper discuss the possibility of using induction welding for creation of spectroscopic cells. This approach improves the optical quality of windows, increase the repeatability of manufacture, and simplify the creation of spectroscopic cells filled with alkali metal vapor. Described technique can be used in the rapidly developing applications, such as quantum frequency standards based on coherent population trapping (CPT). The paper presents a description of the design of cells with flat windows, the results of studies of the spectroscopic properties of the obtained cells and the results of work with the obtained cells used as part of the frequency standard.

The long-term instability of the new generation hydrogen masers

The latest changes in the algorithm for the formation of the international atomic time scale TAI are reported in terms of estimating the weights of the clocks involved in the formation of TAI. Studies of the characteristics of the long-term instability of new-generation hydrogen masers based on processing the results of the clock frequency difference with respect to TAI are performed. It has been confirmed that at present, new-generation hydrogen masers show significantly less long-term instability in comparison with quantum frequency standards ofsimilar and other types.