23 research outputs found
Optical frequency measurement of the 1S-3S two-photon transition in hydrogen
This article reports the first optical frequency measurement of the
transition in hydrogen. The excitation of this
transition occurs at a wavelength of 205 nm which is obtained with two
frequency doubling stages of a titanium sapphire laser at 820 nm. Its frequency
is measured with an optical frequency comb. The second-order Doppler effect is
evaluated from the observation of the motional Stark effect due to a transverse
magnetic field perpendicular to the atomic beam. The measured value of the
frequency splitting is with a relative uncertainty of
. After the measurement of the
frequency, this result is the most precise of the optical frequencies in
hydrogen
Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories
We have built three optical frequency standards based on the two-photon
transition of rubidium at 778Â nm, and analysed their performance over a period of more
than three years. We discuss some systematic effects that could lead to the
reproducibility we observe, and point out the possible improvements of the devices.
We also examine the short and long term stabilities of the systems, and show that we
have reached their ultimate performances
Accurate frequency standard at 1556.2 nm based on a two-photon transition in rubidium for absolute calibration of WDM systems
NRC publication: Ye
Transmission of an optical frequency through a 3Â km long optical fiber
A 3Â km
long optical fiber is used to connect two laboratories in Paris. We
present the metrological properties of this optical link to transfer an optical
frequency standard at 778 nm and we show that the frequency shift introduced by
the fiber is only of few Hz
The strontium single ion standard: application to optical frequency measurements of the 385 THz Rb two photon transitions and the 474 THz I 2/He-Ne standard
NRC publication: Ye