Zobrazeno 1 - 10
of 83
pro vyhledávání: '"John E. Bernard"'
Publikováno v:
2021 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS).
We are developing a transportable ⁸⁸Sr⁺ ion clock for frequency comparisons with optical clocks in remote laboratories. Accuracy limitations found in the current NRC laboratory system, most notably the uncertainties related to the blackbody rad
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d5326a9e823fe571f116bec3f6bede95
https://doi.org/10.1109/eftf/ifcs52194.2021.9604288
https://doi.org/10.1109/eftf/ifcs52194.2021.9604288
Publikováno v:
2017 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFC).
We report a new measurement of the 445 THz electric quadrupole transition of the strontium ion made using a GPS link to the SI second. Compared to our previous measurement reported in 2012, the operation of the optical clock has been improved in seve
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9d1e702134e04c127ec5eab5911e9c45
https://doi.org/10.1109/fcs.2017.8089042
https://doi.org/10.1109/fcs.2017.8089042
Autor:
Bin Jian, Marina Gertsvolf, John E. Bernard, F. Ozimek, Rich Hendricks, Kurt Gibble, A. John Alcock, Krzysztof Szymaniec, Scott Beattie
Publikováno v:
2017 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFC).
At the National Research Council Canada, we are performing final assembly and initial testing of our new atomic fountain clock, NRC-FCs2. This fountain clock incorporates several improvements in the optical, microwave, and computer systems from our p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4aeca80ad398227acd83cce35c15493b
https://doi.org/10.1109/fcs.2017.8088986
https://doi.org/10.1109/fcs.2017.8088986
Publikováno v:
The Precise Time and Time Interval Systems and Applications Meeting.
The demand for secure and accurate time has been growing in recent years in telecommunications, infrastructure, navigation and finance. The requirements are for traceable time with sub micro-second precision. Currently available methods have technica
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e7ff466ac118ac35ddd5a063a7332c83
https://doi.org/10.33012/2017.15013
https://doi.org/10.33012/2017.15013
We report the results of a recent measurement of the absolute frequency of the 5s2 S1/2 – 4d2 D5/2 transition of the 88Sr + ion. The optical frequency was measured against the international atomic time realization of the SI second on the geoid as o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4eb7ca12149bcf51cde57ac7a5322818
https://doi.org/10.1088/1681-7575/aa5e60
https://doi.org/10.1088/1681-7575/aa5e60
Publikováno v:
2016 Conference on Precision Electromagnetic Measurements (CPEM 2016).
At the National Research Council of Canada, we are working to upgrade our cesium fountain clock. The transition from NRC-FCs1 to a second generation fountain, NRC-FCs2, requires the design and assembly of a new physics package. This work is being don
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ee83b034a7b19ea6f7bdd90b3ba4ef9b
https://doi.org/10.1109/cpem.2016.7540694
https://doi.org/10.1109/cpem.2016.7540694
Publikováno v:
Applied Physics B. 89:595-601
We present absolute optical frequency measurements of the 5s2 S 1/2–6p2 P 1/2 hyperfine resolved transitions in both 85Rb and 87Rb near 422 nm. The frequency of each transition was measured by stabilizing a narrow-linewidth extended cavity diode la
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e19c6bfe867d4099d6853c0f55142af7
https://doi.org/10.1007/s00340-007-2836-y
https://doi.org/10.1007/s00340-007-2836-y
Autor:
Jack A. Stone, Martin Zelan, Michael Matus, Helge Karlsson, Alan A. Madej, Antti Lassila, John E. Bernard, Oelof Kruger, Lennart Robertsson
Publikováno v:
Matus, M, Karlsson, H, Stone, J, Krüger, O, Zelan, M, Madej, A A, Bernard, J E, Lassila, A & Robertsson, L 2015, ' The CCL-K11 ongoing key comparison. Final report for the year 2012 ', Metrologia, vol. 52, no. Technical Supplement, 04005 . https://doi.org/10.1088/0026-1394/52/1A/04005
Lasers from ten national metrology institutes (NMIs) plus the institutes responsible for Chinese Taipei and Hong Kong, China, were compared as part of the CCL-K11 ongoing key comparison, initiated by the 13th meeting of the Comit? Consultative des Lo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a20fc0dcd55559c82fefc69602edd105
https://cris.vtt.fi/en/publications/0589051a-df10-4b19-8e01-8528ae2e3d58
https://cris.vtt.fi/en/publications/0589051a-df10-4b19-8e01-8528ae2e3d58
Publikováno v:
Applied Physics B. 79:45-50
An optical frequency comb has been used to measure the frequency of a diode laser system, locked to the P(10), P(11), P(15), P(16), P(20), and P(21) transitions in the ν1+ν3 overtone band of 13C2H2. When locked to any of these transitions, the lase
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b2e80d44108cbc680459cc5895c18364
https://doi.org/10.1007/s00340-004-1516-4
https://doi.org/10.1007/s00340-004-1516-4
Autor:
Massimo Zucco, L. S. Ma, Alan A. Madej, John E. Bernard, Lennart Robertsson, Robert S. Windeler
Publikováno v:
Metrologia. 41:152-160
The absolute optical frequency of a 633 nm, I2-stabilized He–Ne laser system is measured with a femtosecond laser frequency comb. Results over a three-year period using chain- and comb-based measurements yield an operating frequency of ff = (473 61
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::78c98d03126e5cfd958f31cfa666510a
https://doi.org/10.1088/0026-1394/41/3/007
https://doi.org/10.1088/0026-1394/41/3/007