We present an optical cavity design that is insensitive to both vibrations and orientation. The design is based on a spherical cavity spacer that is held rigidly at two points on a diameter of the sphere. Coupling of the support forces to the cavity length is reduced by holding the sphere at a "squeeze insensitive angle" with respect to the optical axis. Finite element analysis is used to calculate the acceleration sensitivity of the spherical cavity for the ideal geometry as well as for several varieties of fabrication errors. The measured acceleration sensitivity for an initial, sub-ideal version of the mounted cavity is 4.0(5)×10(-11)/g, 1.6(3)×10(-10)/g, and 3.1(1)×10(-10)/g (where g = 9.81 m/s2) for accelerations along the vertical and two horizontal directions, and the fractional frequency stability of a laser locked to the cavity is 1.2×10(-15) between 0.4 and 13 s. This low acceleration sensitivity combined with the orientation insensitivity that comes with a rigid mount indicates that this cavity design could allow frequency stable lasers to operate in non-laboratory environments.

Over a two-year duration, we have compared the frequency of the Hg 5d6s S1/2(F = 0) ←→ 5d6s D5/2(F = 2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral Cs. These measurements show that any fractional time variation of the ratio νCs/νHg between the two frequencies is smaller than ±7 × 10 yr (1σ uncertainty). According to recent atomic structure calculations, this sets an upper limit to a possible fractional time variation of gCs(me/mp)α 6.0 at the same level.

Time has always had a special status in physics because of its fundamental role in specifying the regularities of nature and because of the extraordinary precision with which it can be measured. This precision enables tests of fundamental physics and cosmology, as well as practical applications such as satellite navigation. Recently, a regime of operation for atomic clocks based on optical transitions has become possible, promising even higher performance. We report the frequency ratio of two optical atomic clocks with a fractional uncertainty of 5.2 x 10(-17). The ratio of aluminum and mercury single-ion optical clock frequencies nuAl+/nuHg+ is 1.052871833148990438(55), where the uncertainty comprises a statistical measurement uncertainty of 4.3 x 10(-17), and systematic uncertainties of 1.9 x 10(-17) and 2.3 x 10(-17) in the mercury and aluminum frequency standards, respectively. Repeated measurements during the past year yield a preliminary constraint on the temporal variation of the fine-structure constant alpha of alpha/alpha = (-1.6+/-2.3) x 10(-17)/year.

We report on work directed toward the system- atic evaluation of an optical frequency standard based on the - transition of a single, laser-cooled, trapped Hg ion, whose resonance frequency is 1.06 10 Hz. For the purpose of the evaluation, a second Hg standard has been con- structed. In the cooling-laser system built for the second standard, an injection-locking scheme has been applied to a CW Ti-sapphire laser. We also report optical frequency measurements of the clock transition performed over the past 21 months with the first standard. During this term, the variation of the clock transition frequency is found to be less than 1 10 . Index Terms—Injection-locked laser, mercury ion, optical fre- quency standard.

Frequency Standards and Metrology, pp. 361-368 (2002) No AccessQUANTUM COMPUTERS AND ATOMIC CLOCKSD. J. WINELAND, J. C. BERGQUIST, J. J. BOLLINGER, R. E. DRULLINGER, and W. M. ITANOD. J. WINELANDNIST, (Contribution of NIST; not subject to U. S. copyright.) Time and Frequency Division, Boulder, CO, 80305-3328, USA, J. C. BERGQUISTNIST, (Contribution of NIST; not subject to U. S. copyright.) Time and Frequency Division, Boulder, CO, 80305-3328, USA, J. J. BOLLINGERNIST, (Contribution of NIST; not subject to U. S. copyright.) Time and Frequency Division, Boulder, CO, 80305-3328, USA, R. E. DRULLINGERNIST, (Contribution of NIST; not subject to U. S. copyright.) Time and Frequency Division, Boulder, CO, 80305-3328, USA, and W. M. ITANONIST, (Contribution of NIST; not subject to U. S. copyright.) Time and Frequency Division, Boulder, CO, 80305-3328, USAhttps://doi.org/10.1142/9789812777713_0040Cited by:16 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: Recent developments in quantum information processing may be applicable to future atomic clocks. In this paper we discuss two potential applications to trapped-ion frequency standards. In the first, quantum-mechanical entanglement can provide a resource for increased measurement precision in spectroscopy. In the second, we indicate how a simultaneously trapped auxiliary ion species can be used to provide cooling and as a quantum measuring device; this could be used to increase the number of ion species than can be used as frequency standards. FiguresReferencesRelatedDetailsCited By 16Technological trajectories in quantum computing to design a quantum ecosystem for industrial changeMario Coccia19 August 2022 | Technology Analysis & Strategic Management, Vol. 89Quantenlogik‐UhrenPiet O. Schmidt1 July 2021 | Physik in unserer Zeit, Vol. 52, No. 4Coherent laser spectroscopy of highly charged ions using quantum logicP. Micke, T. Leopold, S. A. King, E. Benkler and L. J. Spieß et al.29 January 2020 | Nature, Vol. 578, No. 7793Quantum Logic‐Enabled SpectroscopyPiet O. Schmidt15 April 2019Superposition, entanglement, and raising Schrödinger's catDavid J. Wineland6 September 2013 | Annalen der Physik, Vol. 525, No. 10-11Überlagerungen, Verschränkungen und Schrödingers Katze (Nobel-Aufsatz)David J. Wineland12 August 2013 | Angewandte Chemie, Vol. 125, No. 39Superposition, Entanglement, and Raising Schrödinger's Cat (Nobel Lecture)David J. Wineland12 August 2013 | Angewandte Chemie International Edition, Vol. 52, No. 39Blackbody radiation shifts in optical atomic clocksM. S. Safronova, M. G. Kozlov and C. W. Clark1 Mar 2012 | IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, Vol. 59, No. 3When should we change the definition of the second?Patrick Gill28 October 2011 | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 369, No. 1953Quantum information processing and quantum control with trapped atomic ionsD J Wineland15 December 2009 | Physica Scripta, Vol. T137Production of large molecular ion crystals via sympathetic cooling by laser-cooled Ba +B Roth, A Ostendorf, H Wenz and S Schiller26 September 2005 | Journal of Physics B: Atomic, Molecular and Optical Physics, Vol. 38, No. 20Logical SpectroscopyEkkehard Peik29 Jul 2005 | Science, Vol. 309, No. 5735Spectroscopy of a single Al/sup +/ ion via coupling to Be/sup +/T. Rosenband, P.O. Schmidt, J.C.J. Koelemeij, W.M. Itano and Y. Kobayashi et al.1 Jan 2005Photo-dissociation of Cold MgH $\mathsf{^ + }$ ionsA. Bertelsen, I. S. Vogelius, S. J�rgensen, R. Kosloff and M. Drewsen1 Nov 2004 | The European Physical Journal D, Vol. 31, No. 2Precision Spectroscopy of Molecular Hydrogen Ions: Towards Frequency Metrology of Particle MassesB. Roth, J. Koelemeij, S. Schiller, L. Hilico and J.-P. Karr et al.Ion optical clocks and quantum information processingD.J. Wineland, J.C. Bergquist, T. Rosenband, P.O. Schmidt and W.M. Itano et al. Frequency Standards and MetrologyMetrics History PDF download

NIST has a more than 50-year history of developing ever more accurate atomic frequency standards. For most of that time, the technology was based on thermal atomic beams of cesium atoms, and the accuracy improvement was approximately a factor of 10 every 7 years. To put this into some kind ofperspective, both the period of this history and the rate of improvement are almost identical to the development of information-storage density in magnetic medid Now, however, with the advent of laser-cooling schemes and optical- frequency metrology, the rate of progress is dramatically increasing. This paper discusses briefly the last of the thermal-beam standards and our first laser-cooled, atomic-fountain standard. It then goes into some detail about the newly developed all-optical standards that use an optical-frequency transition in a single, laser-cooled, trapped mercury ion or in an ensemble of laser-cooled and trapped calcium atoms. Based largely on the increased operating frequency of the "clock" transition, these new standards have the potential for several orders of magnitude improvement in stabirity and, in the case of the mercury standard, accuracy over today's standards operating in the microwave region.

Microwave atomic clocks have been the de facto standards for precision time and frequency metrology over the past 50 years, finding widespread use in basic scientific studies, communications, and navigation. However, with its higher operating frequency, an atomic clock based on an optical transition can be much more stable. We demonstrate an all-optical atomic clock referenced to the 1.064-petahertz transition of a single trapped Hg ion. A clockwork based on a mode-locked femtosecond laser provides output pulses at a 1-gigahertz rate that are phase-coherently locked to the optical frequency. By comparison to a laser-cooled calcium optical standard, an upper limit for the fractional frequency instability of 7 3 10 is measured in 1 second of averaging—a value substantially better than that of the world’s best microwave atomic clocks.

CRL and NIST have completed the development of CRL-O1, an improved optically pumped primary frequency standard. The results of the first evaluation of the new standard and its comparison with NIST-7, the US primary frequency standard are presented

We have achieved a stability of 3 10 13 1=2 for 3 < < 30 s with a laser-pumped rubidium gas-cell frequency standard by reducing the effects due to noise in the microwave and laser sources. This result is one order of magnitude better than the best present performance of lamp-pumped devices.

We present a theoretical comparison between a TE01n cavity and a traditional Ramsey cavity when used with a laser-cooled atom source in a microgravity clock.

we report the improvement of short term stability (5.10-’3 z-’~) that has been obtained with a laserpumped passive gas-cell frequency standard. Three types of lasers, including extended cavity (EC), solitary and DBR lar.ers, have been used with different stabilization schemes. Their amplitude modulation (AM) noise and phase modulation (PM) noise have been measured and compared. The requirements on the accuracy and on the stability of their frequency stabilization have been established by light sM measurements which were performed with simultaneous heterodyne detection of the laser frequeng. The use of the DI line instead of the D2 line of Rb is also discussed. The possibility of simultaneously making the two light shift coefficients (Avdd /A Irar and Avdd /Avlmr) zero is described. Some limitations due to the microwave synthesizer are presented. Finally, clock stability measurements are presented and discussed.