Direct measurement of the 7s 2S1/2 → 7p 2P3/2 transition frequency in 226Ra+

C. A. Holliman, M. Fan, A. Contractor, M. W. Straus, A. M. Jayich
PRA 102, 042822 (2020)

We report a direct measurement of the 7s 2S1/2 → 7p 2P3/2 electric dipole transition frequency in 226Ra+. With a single laser-cooled radium ion we determine the transition frequency to be 785722.11(3) GHz by directly driving the transition with frequency-doubled light and measuring the frequency of the undoubled light with an iodine reference. This measurement addresses a discrepancy of five combined standard deviations between previously reported values.