Abstract
We report the measurement of absolute excitation frequencies of to and Rydberg states. The Rydberg transition frequencies are obtained by observing electromagnetically induced transparency on a rubidium vapor cell. The accuracy of the measurement of each state is 1 MHz, which is achieved by frequency stabilizing the two diode lasers employed for the spectroscopy to a frequency comb and a frequency comb calibrated wavelength meter, respectively. Based on the spectroscopic data we determine the quantum defects of , and compare it with previous measurements on . We determine the ionization frequency from the ground state of to , providing the binding energy of the ground state with an accuracy improved by two orders of magnitude.
- Received 23 February 2011
DOI:https://doi.org/10.1103/PhysRevA.83.052515
©2011 American Physical Society