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We are developing a highly miniaturized trapped ion clock to probe the 12.6 GHz hyperfine transition in the 171Yb+ion. The clock development is being funded by the Integrated Micro Primary Atomic Clock Technology (IMPACT) program from DARPA where the stated goals are to develop a clock that consumes 50 mW of power, has a size of 5 cm3, and has a long-term frequency stability of 10-14at one month. One of the significant challenges will be to develop miniature single-frequency lasers at 369 nm and 935 nm and the optical systems to deliver light to the ions and to collect ion fluorescence on a detector.

We present an evaluation of the long-term frequency instability and environmental sensitivity of a chip-scale atomic clock based on coherent population trapping, particularly as affected by the light-source subassembly. The long-term frequency stability of this type of device can be dramatically improved by judicious choice of operating parameters of the light-source subassembly. We find that the clock frequency is influenced by the laser-injection current, the laser temperature, and the rf modulation index. The sensitivity of the clock frequency to changes in the laser-injection current or the substrate temperature can be significantly reduced through adjustment of the rf modulation index. This makes the requirements imposed on the laser-temperature stabilization, in order to achieve a given frequency stability, less severe. The clock-frequency instability due to variations in local oscillator power is shown to be reduced through the choice of an appropriate light intensity inside the cell. The importance of these parameters with regard to the long-term stability of such systems is discussed.

A laser-cooled neutral-atom beam from a low-velocity intense source is split into two beams while it is guided by a magnetic-field potential. We generate our multimode beam-splitter potential with two current-carrying wires upon a glass substrate combined with an external transverse bias field. The atoms are guided around curves and a beam-splitter region within a 10-cm guide length. We achieve a maximum integrated flux of 1.5×10^5 atoms/s with a current density of 5×10^4 amp/cm^2 in the 100‐µm-diameter wires. The initial beam can be split into two beams with a 50/50 splitting ratio.