Title :
The optical calcium frequency standard
Author :
Riehle, F. ; Schnatz, H. ; Lipphardt, B. ; Zonner, G. ; Trebst, T. ; Helmcke, J.
Author_Institution :
Phys. Tech. Bundesanstalt, Braunschweig, Germany
Abstract :
PTB operates an optical wavelength/frequency standard by stabilizing the frequency of a laser to the intercombination transition /sup 3/P/sub 1/-/sup 1/S/sub 0/ of atomic /sup 40/Ca at /spl lambda//spl cong/657 nm. The relative uncertainty of the standard has been reduced by the use of laser cooled atoms and by measurements of the optical frequency to below 2.5/spl middot/10(-13).
Keywords :
atomic clocks; calcium; frequency standards; laser cooling; laser frequency stability; measurement uncertainty; radiation pressure; resonant states; 657 nm; Ca; Ramsey excitation; atomic /sup 40/Ca; intercombination transition; laser cooled atoms; laser frequency stabilization; laser manipulation; magneto-optical traps; metre definition; optical calcium frequency standard; optical wavelength/frequency standard; relative uncertainty; Atom lasers; Atom optics; Atomic beams; Atomic measurements; Calcium; Frequency measurement; Laser transitions; Measurement standards; Optical interferometry; Optical resonators;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 1998 Conference on
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-5018-9
DOI :
10.1109/CPEM.1998.699917
