1S-2S transition frequency measurements in atomic hydrogenN. KolachevskyMPQ

HydrogenTheoryFrequency combMobile fountain clockOptical fiber linkChristian PartheyArthur MatveevJanis AlnisAxel BeyerNikolai KolachevskyRandolf PohlThomas UdemTheodor HncshTobias WilkenBirgitta BenhardtUlrich JentsBrett Altschul Michel AbgrallDaniele Rovera Christophe SalomonPhilippe LaurentKatharina PredehlStefan DrosteRonald HolzwarthHarald SchnatzGesine GroscheThomas LegeroStefan WeyersThe Team

Hydrogen Levels (n = 1, 2)BohrDiracQEDHyperfinestructure

Hydrogen Levels (n = 1, 2)BohrDiracQEDHyperfinestructure

Energy levelsSchrdinger: recoil: finite nuclear size:

Talk by Randolf Pohl, Monday

N. Kolachevsky et al., Opt. Lett. 36, 4299 (2011)

972 nm diode laser with a 20 cm long external resonator and intra-cavity EOMBeat note diode - dye laserMaster oscillator

FP at zero expansion temperatureTypical drift @ Tc is of 50 mHz/sJanis Alnis

FP1-FP2 Allan deviationThermal noise limit

Fiber LaserI()Hydrogen maserStabilized optical fiberFP5DistributionamplifierWenzel Chain 4 5 5Wenzel Chain 4 5 5PLLPLLI()temperature stabilized1GHz1GHzComb-comb comparison setup250 MHzsystem100 MHzsystem1542 nm

Comb-comb comparison: result

In zero magnetic field B:known preciselyto be measured1420 405.751 768(1) HzOptical measurement of the 2S HFS

2s HFS result - 2009N. Kolachevsky et al., PRL 102, 213002 (2009)FFK2009

Frequency [Hz]Uncertainty [Hz]Averaged interval frequency177 556 835.36.2Line shape / temperature02AC Stark shift01.2DC Stark shift-11Magnetic fields00.5Total177 556 834.36.7

C.G. Parthey et al., PRL 107, 203001 (2011)

C.G. Parthey et al., PRL 107, 203001 (2011)

C.G. Parthey et al., PRL 107, 203001 (2011)

*Mobile fountain clock

Thank you for attention!C.G. Parthey et al., PRL 107, 203001 (2011)