We report the measurement of transition frequencies of Rb85 atoms in a room-temperature vapor cell to nP1/2 (n=34–53) and nP3/2 (n=34–87) Rydberg levels by observing single-photon Rydberg excitation spectroscopy. Based on the spectroscopic data, we determine quantum defects that are in good agreement with previous measurements of low-lying Rydberg states. Furthermore, the residuals between observed and calculated values of fine-splitting intervals in our experiments are found to be less than 10 MHz.
Millimeter resonances corresponding to single- and double-photon transitions have been observed between Rydberg levels of sodium with principal quantum number
n ranging from 23 to 41. The levels are prepared by laser excitation; transitions are induced by microwaves produced by a backwave oscillator working around 300 GHz; detection is performed through the selective field-ionization technique. Experimental values for quantum defects, fine-structure intervals, and polarizabilities are reported.
Abstract We present experiments on two‐photon excitation of 87Rb atoms to Rydberg states. For this purpose, two continuous‐wave (cw)‐laser systems for both 780 nm and 480 nm have been set up. These systems are optimized to a small linewidth (well below 1 MHz) to get both an efficient excitation process and good spectroscopic resolution. To test the performance of our laser system, we investigated the Stark splitting of Rydberg states. We were able to see for both of the n = 41D finestructure states the electrical field dependent |mj| splitting. To show the ability of spatially selective excitation to Rydberg states, we excited rubidium atoms in an electrical field gradient and investigated both linewidths and lineshifts. Furthermore we were able to excite the atoms selectively from the two hyperfine ground states to Rydberg states. Finally, we investigated the Autler‐Townes splitting of the 5S1/2(F = 2)→5P3/2(F = 3) transition coupled to the light field via a Rydberg state to determine the Rabi frequency of this excitation step.
We report the measurement of the absolute transition frequencies of
87Rb atoms to the
nP1/2 (
n=34−−52) and
nP3/2 (
n=34−−90) Rydberg states by performing single-photon Rydberg excitation spectroscopy in a vapor cell. Rydberg transitions were detected by monitoring the transmission of a 780-nm probe beam. Based on the spectroscopic data, we determined the fine-splitting intervals and oscillator-strength ratios of the
nP doublets and also extracted the quantum defects and ionization frequency. These results extend the spectroscopic information of the
nP Rydberg series, providing basic knowledge for further applications to Rydberg atoms.
The multiphoton excitation of rubidium has been investigated over the 4600-6500-\AA{} wavelength region with a tunable dye-laser source having a linewidth better than 0.1 \AA{} and a space-charge ionization detector sensitive to a few ions per second. Multiphoton transitions have been observed to occur both through intermediate atomic states and through intermediate continuum states of the rubidium molecule. In the former case two-photon transitions have been observed from the
52S ground state of atomic rubidium to higher-lying
n2D levels for values of
n ranging from 9 to 34 and to
n2S levels for values of
n from 11 through 20. The fine-structure intervals of the
n2D levels for
n=9toc13 were measured together with the line-strength ratios and were found to be in good agreement with the predictions of a simple theoretical model. At the shorter wavelengths hybrid two-photon resonances were observed to be excited through resonant intermediate continuum states of
Rb2. As a result the dispersion curve for two-photon absorption in rubidium showed what appears to be resonant intermediate $p\ensuremath{\pi}(^{3}\ensuremath{\Sigma}_{u1})$ and
0g+ terms dissociating to give a
5P23 atom and resulting in the strong development of features corresponding to the $5^{2}P_{\frac{3}{2}}\ensuremath{\rightarrow}n^{2}D_{\frac{3}{2},\frac{5}{2}}$ part of the diffuse series, for $n\ensuremath{\le}50$ in absorption and the $5^{2}P_{\frac{3}{2}}\ensuremath{\rightarrow}n^{2}S_{\frac{1}{2}}$ part of the sharp series. Components to
322D and
302S were recorded to a precision of 0.3 ${\mathrm{cm}}^{\ensuremath{-}1}$ and quantum defects for these previously unobserved terms were derived. The corresponding hybrid two-photon resonances involving intermediate states dissociating to give a
52P21 atom were not observed in the wavelength interval available in this experiment.