Absolute frequency determination of the 5P3/2→7S1/25P_{3/2} \rightarrow 7S_{1/2} transition in 87Rb^{87}Rb

We report the absolute frequency of the important $5S_{1/2} \rightarrow 7S_{1/2}$ two-photon transition in $^{87}Rb$. We access the upper state using two dipole-allowed transitions via the intermediate $5P_{3/2}$ state. This allows us to use much lower laser intensities compared to directly driving the two-photon transition, thereby avoiding potential errors due to the AC Stark shift. Collisional shifts are also minimized because the atomic density required is several orders of magnitude smaller. Our values are consistent with earlier frequency-comb measurements

Absolute frequency determination of the 5P3/2→7S1/25P_{3/2} \rightarrow 7S_{1/2} transition in 87Rb^{87}Rb

We report the absolute frequency of the important $5S_{1/2} \rightarrow 7S_{1/2}$ two-photon transition in $^{87}Rb$. We access the upper state using two dipole-allowed transitions via the intermediate $5P_{3/2}$ state. This allows us to use much lower laser intensities compared to directly driving the two-photon transition, thereby avoiding potential errors due to the AC Stark shift. Collisional shifts are also minimized because the atomic density required is several orders of magnitude smaller. Our values are consistent with earlier frequency-comb measurements

Isotope shifts and hyperfine structure in the 555.8-nm S-1(0) -> P-3(1) line of Yb

We apply our technique of using a Rb-stabilized ring-cavity resonator to measure the frequencies of various spectral components in the 555.8-nm 1S0-->3P1 line of Yb. We determine the isotope shifts with 60 kHz precision, which is an order-of-magnitude improvement over the best previous measurement on this line. There are two overlapping transitions, 171Yb(1/2-->3/2) and 173Yb(5/2-->3/2), which we resolve by applying a magnetic field. We thus obtain the hyperfine constants in the 3P1 state of the odd isotopes with a significantly improved precision. Knowledge of isotope shifts and hyperfine structure should prove useful for high-precision calculations in Yb necessary to interpret ongoing experiments testing parity and time-reversal symmetry violation in the laws of physics