Abstract
Spectroscopy of the 411-nm transition in has been performed and the feasibility of its use as an optical frequency standard has been demonstrated. The frequency, at zero-magnetic field, has been measured to be 729 487 779 566(153) kHz. This transition is free from the first-order Zeeman shift and has a measured second-order shift of +0.38(8) Hz/(μ. In addition, the hyperfine structure of the level has been deduced by driving the other hyperfine components of the 411-nm transition, showing it to be inverted. The hyperfine splitting, measured to be -191(2) MHz, implies an A factor of -63.6(7) MHz. These data taken in conjunction with previous work yield an isotope shift of for this transition between the 171 and 172 isotopes.
- Received 20 November 1998
DOI:https://doi.org/10.1103/PhysRevA.60.2867
©1999 American Physical Society