Micro Ion Frequency Standard

Abstract : We are developing a highly miniaturized trapped ion clock to probe the 12.6 GHz hyperfine transition in the (sup 171)Yb+ 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 cubic cm, and has a long-term frequency stability of 10(exp -14) at 1 month. Trapped ion systems are an excellent candidate for such extreme miniaturization, because ions are well isolated from the environment independently of the size of the trap. Trapped ion clocks are characterized by quality factors, Q, in excess of 10(exp 12) and excellent long-term stability, and the Q will be minimally degraded upon miniaturization. To realize the clock in a small package will require the miniaturization of several technologies. One of the primary technologies will be the miniaturized ion trap and vacuum package. Linear RF Paul traps routinely have dimensions of a couple millimeters, but miniaturizing the vacuum package with an integral trap, Yb source, and pump will require a novel design. Integrating the miniature, low-power light sources for state detection at 369 nm and 935 nm and for photoionization at 399 nm will also be critical. The 369 nm laser will be a frequency-doubled vertical external cavity surface-emitting laser (VECSEL). A low-phasenoise local oscillator at 12.6 GHz will also be developed using a micro resonator based on exciting acoustic resonances in aluminum nitride. We will present our proposed approach to developing the micro ion frequency standard and relevant current results.