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Q: Quantenoptik
Q 29: Application of Short Pulses II
Q 29.1: Group Report
Thursday, April 5, 2001, 17:30–18:00, H 2013
Measurement of the absolute frequencies of the Ca- and Yb+ optical clock transitions using a femtosecond-laser frequency comb — •Jörn Stenger1, Thomas Binnewies1, Nils Haverkamp1, Fritz Riehle1, Christian Tamm1, Harald Telle1, Guido Wilpers1, and Robert S. Windeler2 — 1Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig — 2Lucent Technologies, Murray Hill, New Jersey, USA
We applied a femtosecond-laser frequency comb to phase-coherently link PTB’s cold-atom based Ca frequency standard and the single-ion Yb+ standard to the Cs primary standard. A first measurement of the Ca 1S0 − 3P1 intercombination transition at 657 nm yielded a frequency νCa = 455 986 240 494 276 Hz, which agrees within its relative uncertainty of 4× 10−13 with the values previously measured with the PTB’s harmonic frequency chain and with the value recommended by the CIPM. Recent improvements led to a <10−12/τ instability of the measurement process. An updated value for the Ca standard and a first value for the Yb+ 2S3/2 − 2D3/2 clock transition will be presented at the conference.