The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We report a frequency measurement of the 4s21 S0-4S4p 3P1 transition in calcium performed for the first time with ultracold atoms. The density dependence of the transition frequency was determined and a dipole trap realized
Sr-atoms are of special interest for an optical frequency standard since a large number of atoms can be cooled down efficiently to ultra-low temperatures in a magneto-optical trap (MOT) [1]. The ultra-narrow line on the forbidden 1S0 → 3P0 transition of 87Sr (3P0 natural lifetime is approx. 100 s), and the ability to interrogate Sr atoms in a perturbation free dipole trap [2] promise un-precedented...
An optical frequency standard is operated at PTB where the frequency of a laser is stabilized to the intercombination transition (λ ≈ 657 nm) in laser cooled Ca atoms. Previously the uncertainty resulting from the residual velocity of the cold atoms at 3 mK limited the fractional uncertainty to 2 × 10−14. We now apply a novel method for producing ultra-cold atoms (λ ≈ 10 µK). The frequency of the...
Abstract. We have investigated the two major effects that limit the accuracy of an optical frequency standard based on laser-cooled neutral calcium atoms, i.e. the residual Doppler shift and atomic collisions. A new correction method was applied to reduce the contribution of the residual Doppler effect to the total fractional uncertainty to 110-14. Measurements of the shift of the clock transition...
We report on the development and characterization of a transportable frequency standard to disseminate one of the most precisely known optical frequencies, the frequency of the Ca intercombination line at 657nm. The key components of the transportable standard are a pre-stabilized diode laser system with a laser linewidth of below 2kHz and a miniaturized thermal calcium beam apparatus. A separated-field...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.