Extra-laboratory atomic clocks are necessary for a wide array of applications (e.g. satellitebased navigation and communication). Building upon existing vapor cell and laser technologies, we describe an optical atomic clock, designed around a simple and manufacturable architecture, that utilizes the 778 nm two-photon transition in rubidium and yields fractional frequency instabilities of 3 × 10 −13 / τ (s) for τ from 1 s to 10000 s. We present a complete stability budget for this system and explore the required conditions under which a fractional frequency instability of 1 × 10 −15 can be maintained on long timescales. We provide precise characterization of the leading sensitivities to external processes including magnetic fields and fluctuations of the vapor cell temperature and 778 nm laser power. The system is constructed primarily from commercially-available components, an attractive feature from the standpoint of commercialization and deployment of optical frequency standards.

The 5S 1/2 → 5D 5/2 two-photon transition in Rb is of interest for the development of a compact optical atomic clock. Here we present a rigorous calculation of the 778.1 nm ac-Stark shift (2.30(4) × 10 −13 (mW/mm 2 ) −1 ) that is in good agreement with our measured value of 2.5(2) × 10 −13 (mW/mm 2 ) −1 . We include a calculation of the temperature-dependent blackbody radiation shift, we predict that the clock could be operated either with zero net BBR shift (T = 495.9(27) K) or with zero first-order sensitivity (T = 368.1(14) K). Also described is the calculation of the dc-Stark shift of 5.5(1)×10 −15 /(V/cm 2 ) as well as clock sensitivities to optical alignment variations in both a cat's eye and flat mirror retro-reflector. Finally, we characterize these Stark effects discussing mitigation techniques necessary to reduce final clock instabilities.

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Treatment of Fe(η5-C5H5)(η1-NC4H4)(CO)2 (1) with N(Bu)4S208 in the presence of dodecylbenzenesulfonic acid leads to the formation of a soluble, electrically conducting polymer (2). Solutions of 2 lose CO upon heating to give a new polymer, 3, which is postulated to contain primarily azaferrocene units in the backbone.

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