We present the results obtained in course of development an optical frequency standard based on cold 87Sr atoms. describe parameters experimental schemes developed for realization all stages consecutive laser cooling and trapping atoms lattice. The procedure clock transition spectroscopy was successfully performed with a spectral linewidth 12 Hz. A measuring complex femtosecond synthesizer is d...

Diode lasers are becoming increasingly important in length metrology. We demonstrate construction of a simple single-frequency diode laser 632,8 nm, used as a frequency standard in the laser interferometers. We present two different systems applied for frequency stabilization of diode laser . For diode laser used as the secondary standard, the system stabilizes diode temperature, the frequency ...

Our group at the National Institute of Standards and Technology (NIST) is in the initial phase of developing a prototype laser-cooled atomic frequency standard (AFS) for potential use in a future global positioning system (GPS) system. The expected fractional frequency stability or Allan deviation, σy(τ), will be 2 × 10 -13 at one second, improving as the square-root of the averaging time to 7 ...

A stable and accurate frequency standard based on the 40.5 GHz ground-state hyperfine transition in 199Hg1 ions is described. The ions are confined in a cryogenic linear Paul (rf ) trap and laser cooled to form a linear crystal. With seven ions and a Ramsey interrogation time of 100 s, the fractional frequency stability is 3.3 s2d 3 10213t21y2 for measurement times t , 2 h. The ground-state hyp...

The National Institute of Standards and Technology is developing an optically pumped, cesium-beam primary frequency standard. The design follows from an analysis of systematic errors found in cesium beam standards. The details of the design, performance of major subsystems, and preliminary tests of the standard are presented.

This paper reviews the present methods of distributing standard frequency and time signals (SFTS), which include the use of high-frequency, low-frequency, and very-low-frequency radio signals, portable clocks, satellites, and RF cables and Lines. The range of accuracies attained with most of these systems is included along with an indication of the sources of error. Information is also included...