Measurement of the infrared 2F7/2-2D5/2 transition in a single 171Yb+ ion

The F-2(7/2)(F=3)-D-2(5/2)(F=2) 3.43 mu m transition in Yb-171(+) has been measured to be 87 366 282 258(91) kHz. This transition is of interest as an infrared frequency standard. A subsidiary measurement of the 3.43-mu m (F = 4-F' = 3) transition yields a frequency of 87 362 471 500(800) kHz. Taken with a previous measurement of the 2D(5/2) level hyperfine splitting, a 2F(7/2) level hyperfine splitting of 3620(2) MHz and an A factor of 905.0(0.5) MHz are deduced. In addition, a 3.43-mu m transition isotope shift of v(171)-v(72)= + 4048(4) MHz is obtained from these experiments and a known value for the transition in the 172 isotope. These measurements taken with previous work give a value for the S-2(1/2)(F=0)-F-2(7/2)(F=3) electric octupole transition of 642 121 497 308(178) kHz, which will be used as a starting point in the search for this extremely weak transition. [S1050-2947(99)04610-7].