Title :
Optical frequency standards
Author :
Helmcke, Jurgen ; Morinaga, Atsuo ; Ishikawa, Jun ; Riehle, Fritz
Author_Institution :
Phys.-Tech. Bundesanstalt, Braunschweig, West Germany
fDate :
4/1/1989 12:00:00 AM
Abstract :
Frequency standards operating in the optical range promise very low frequency uncertainties due to the high spectral resolution and the small sensitivity to external fields. Basic ideas and concepts for the development of optical frequency standards are reviewed with emphasis to laser cooling and ion storing. Utilizing cooled absorbers, potential fractional frequency uncertainties below 10-15 are envisaged. Phase-coherent frequency measurements of laser radiation at λ=3.39 μm and a concept for an extension towards the visible range are discussed. A Ca optical frequency stabilized to the intercombination line (λ≈657 nm) utilizing Ramsey excitation of a single recoil component is described. The present estimated fractional uncertainty to find the Ca line center is about 2.3×10 -12. It can probably be improved significantly by reducing phase shifts of the Ramsey excitation and by atomic beam cooling
Keywords :
atomic beams; calcium; frequency measurement; measurement by laser beam; measurement standards; 3.39 micron; 657 nm; Ca; Ramsey excitation; atomic beam cooling; cooled absorbers; high spectral resolution; intercombination line; ion storing; laser cooling; optical frequency standards; phase coherent frequency measurement; phase shifts; Atom optics; Atomic beams; Cooling; Frequency measurement; Laser stability; Nonlinear optics; Optical resonators; Optical sensors; Particle beam optics; Standards development;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
