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Q: Quantenoptik und Photonik
Q 32: Poster Laserspektroskopie und Laser in der Umweltmesstechnik
Q 32.4: Poster
Thursday, March 25, 2004, 14:00–16:00, Schellingstr. 3
Optical Frequency Standard with Cold Sr Atoms — •Paul-Eric Pottie, Tomas Binnewies, Hardo Stoehr, Uwe Sterr, Juergen Helmcke, and Fritz Riehle — Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig
A new optical frequency standard with cold Sr atoms is under construction at PTB. 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 promise an unprecedented small inaccuracy and a relative frequency instability, well below 10−15τ−1/2. The spectral noise density of the interrogation laser frequency fluctuations and its spectral aliasing by the Dick effect are key parameters for the frequency instability of the future frequency standard. To reach the frequency instability that would be possible with long interaction times in a dipole trap, the low frequency fluctuations of the interrogation laser frequency have to be reduced, using a pre-stabilization scheme. For this pre-stabilization it is essential to get as many cold atoms as possible in a time as short as possible. Our experimental set-up is optimized for that purpose. Sr atoms are first slowed in a Zeeman slower, then deflected with the help of a 2-D molasses, and trapped in a MOT. We will present the parameters of our MOT and its implication on an optical frequency standard.We will show the realization of an efficient atomic source of cold Sr atoms and the construction of an ultra-stable laser for the interrogation of the atoms.