Absolute frequency and isotope shift measurements of mercury 1S0-3P1 transition

• Published in: Optics express Vol. 27; no. 8; pp. 11069 - 11083
• Main Authors: Witkowski, Marcin, Kowzan, Grzegorz, Munoz-Rodriguez, Rodolfo, Ciuryło, Roman, Żuchowski, Piotr Szymon, Masłowski, Piotr, Zawada, Michał
• Format: Journal Article
• Language: English
• Published: 15-04-2019
• ISSN: 1094-4087
• DOI: 10.1364/OE.27.011069

We report the measurement of the absolute frequencies of the 6s2 1S0-6s6p 3P1 transition (253.7 nm) and the relevant isotope shifts in five mercury isotopes  198Hg,  199Hg,  200Hg,  202Hg, and  204Hg. The Doppler-free saturated absorption measurements were performed in an atomic vapour cell at room temperature with a four-harmonic generated (FHG) continuous-wave (cw) laser digitally locked to the atomic transition. It was referenced with a femtosecond optical frequency comb synchronized to the frequency of local representation of the International Atomic Time to provide traceability to the SI second by the 330 km-long stabilized fibre optical link. The transition frequencies and isotope shifts have been determined with an accuracy of a few hundred kHz, at least one order of magnitude better than any previous measurement. By making a King plot with the isotope shifts of 6s6p 3P2-6s7s 3S1 transition (546 nm) we determined the accurate value of the ratio of the electronic field-shift parameters E546/E254 and estimated the electronic field-shift term E254.