Hyperfine structure of the7d2D3/2level in cesium measured by Doppler-free two-photon spectroscopy

Abstract

We report the measurement of the hyperfine structure in the 7d 2 D 3/2 state of 133 Cs isotope by Doppler-free two-photon fluorescence spectroscopy in a gas cell. The hyperfine level separations were measured using a frequency-stabilized Ti:sapphire laser locked to one of the hyperfine transitions and an acousto-optic modulator locked to another hyperfine transition. The frequency separation between various hyperfine levels has been measured with a precision of ∼100 kHz. From the measured hyperfine separations of the excited state, we have determined the magnetic dipole coupling constant (A) and electric quadrupole coupling constant (B) for the 7d 2 D 3/2 state. The determined hyperfine structure constants are A = 7.38 (0.01) MHz and B = −0.18 (0.1) MHz. The values measured are found to be in good agreement with the earlier reported results using stepwise excitation process.

Frequency measurement of the 6P3/2→7S1/2transition of thallium

“…It is a Fizeau based wavelength meter and a similar wavelength meter has been used to measure the hyperfine splitting in Cs to an accuracy of 0.5 MHz [17,18]. Our wavelength meter has an absolute accuracy of 30 MHz in 10 h [19] after it is calibrated against a stabilized laser with an accurately known frequency.…”