Test of iodine cells using the Hanle effect

SIGLELD:6029.335(NPL-MOM--51) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Precision measurement of the ²F_7/2-²D_5/2 3.43 μm interval trapped ¹⁷²Yb⁺

The 4f<sup>13</sup> 6s<sup>2</sup> <sup>2</sup>F<sub>7/2</sub>–4f<sup>14</sup> 5d <sup>2</sup>D<sup>5/2</sup> 3•43 μm infrared transition in <sup>172</sup>Yb<sup>+</sup> has been driven for the first time and measured to be 87 360 087(4) MHz. The frequency was determined by probing a cloud of <sup>172</sup>Yb<sup>+</sup> ions held in a radiofrequency trap in the presence of helium buffer gas. The infrared radiation was generated by difference frequency mixing in LiNbO<sub>3</sub>. The frequency measurement is part of a programme to locate the 4f<sup>14</sup> 6s <sup>2</sup>S<sub>1/2</sub>–4f<sup>13</sup> 6s<sup>2</sup> <sup>2</sup>F<sub>7/2</sub> 467 nm ultra-narrow transition in laser-cooled Yb<sup>+</sup>

Measurement of the s-2(1/2)-d-2(5/2) clock transition in a single yb-171(+) ion

Spectroscopy of the 411-nm transition in 171Yb+ has been performed and the feasibility of its use as an optical frequency standard has been demonstrated. The 2S1/2(F=0, mF=0)-2D5/2(F=2, mF=0) 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/(μT)2. In addition, the hyperfine structure of the 2D5/2 level has been deduced by driving the other hyperfine components of the 411-nm transition, showing it to be inverted. The 2D5/2 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 ν171-ν172=+1317.1(1.3)MHz for this transition between the 171 and 172 isotopes

Analysis of laser frequency stability by heterodyne measurement

SIGLEAvailable from British Library Document Supply Centre- DSC:6029.335(NPL-MOM--78) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Investigation of the s-2(1/2)-d-2(5/2) clock transition in a single ytterbium ion

The suitability of the 411-nm 2S1/2-2D5/2 transition in Yb+ is assessed as an optical frequency standard. The lifetime of the 2D5/2 level has been measured and found to be 7.2±0.3 ms, which implies a natural linewidth of 22.2±0.9 Hz for the 411-nm transition. In addition to a decay to the ground state the 2D5/2 level can decay into the highly metastable 2F7/2 level where it is trapped. The branching ratio for decay into the 2F7/2 level has been measured and found to be 0.83±0.03. A transition capable of rapidly depopulating the 2F7/2 level and returning the ion to the cooling cycle has been demonstrated. This has enabled a quantum jump measurement of the 411-nm transition in 172Yb+ to be performed, yielding a center frequency of 729 476 869.13(0.42) MHz (1σ)

A rubidium stabilised laser diode for interferometry

SIGLEAvailable from British Library Document Supply Centre- DSC:6029.335(NPL-MOM--85) / BLDSC - British Library Document Supply CentreGBUnited Kingdo