Optical Atomic Clock: A long look at the captured atoms

February 5, 2008

Optical clocks might become the atomic clocks of the future. Their "pendulum", i.e. the regular oscillation process which each clock needs, is an oscillation in the range of the visible light. As its frequency is higher than that of the microwave oscillations of the cesium atomic clocks, physicists expect another increase in the accuracy, stability and reliability.

In the case of one of the candidates for an optical clock which is developed at Physikalisch-Technische Bundesanstalt (PTB), strontium atoms are retained in the interference pattern of two laser beams.

In this so-called "optical grating" the atomic "pendulum", i.e. the absorption frequency of the atoms, can then be measured very exactly. For this optical grating clock, the loading of cold atoms into an optical grating has been optimized to such an extent that approx. 106 strontium atoms are loaded into the grating within 150 milliseconds at a temperature of a few microkelvin.

There, the atoms remain stored for over one second and are available for a precision measurement of the optical frequency.

This value would serve for the redefinition of the base unit "second" provided that additional investigations and international comparison show that this frequency can be determined with sufficient accuracy.

Source: Physikalisch-Technische Bundesanstalt

Explore further: A better way to control crystal vibrations

Related Stories

A better way to control crystal vibrations

May 21, 2018

The vibrational motion of an atom in a crystal propagates to neighboring atoms, which leads to wavelike propagation of the vibrations throughout the crystal. The way in which these natural vibrations travel through the crystalline ...

Researchers develop module for quantum repeater

May 22, 2018

Physicists at Saarland University in Saarbrücken, Germany, have succeeded in entangling a single atom with a single photon in the telecom wavelength range. This constitutes a basic building block for transmission of quantum ...

Neglected atom has top properties for atomic clocks

May 11, 2018

Like watchmakers choosing superior materials to build a fine timepiece, physicists at the Centre for Quantum Technologies (CQT) at the National University of Singapore have singled out an atom that could allow them to build ...

Recommended for you

How can you tell if a quantum memory is really quantum?

May 23, 2018

Quantum memories are devices that can store quantum information for a later time, which are usually implemented by storing and re-emitting photons with certain quantum states. But often it's difficult to tell whether a memory ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.