Advertisement

Optical Frequency Standards Based on Neutral Atoms and Molecules

  • Fritz Riehle
  • Jürgen Helmcke
Chapter
Part of the Topics in Applied Physics book series (TAP, volume 79)

Abstract

The current status and prospects of optical frequency standards based on neutral atomic and molecular absorbers are reviewed. Special attention is given to an optical frequency standard based on cold Ca atoms which are interrogated with a pulsed excitation scheme leading to resolved line structures with a quality factor Q τ; 1012. The optical frequency was measured by comparison with PTB’s primary clock to be νCa = 455 986 240 494.13 kHz with a total relative uncertainty of 2.5 × 10−13. After a recent recommendation of the International Committee of Weights and Measures (CIPM), this frequency standard now represents one of the most accurate realizations of the length unit.

Keywords

Laser Frequency Neutral Atom Atomic Beam Frequency Standard Laser Cool 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Bureau International des Poids et Mesures (BIPM): Report of the 86th meeting of the Comité International des Poids et Mesures (CIPM), Sevres, Paris (1997)Google Scholar
  2. 2.
    Editor’s note: Documents concerning the new definition of the metre. Metrologia 19, 163–177 (1984)Google Scholar
  3. 3.
    S. N. Bagayev, V. P. Chebotayev, A. K. Dmitriyev, A. E. Om, Y. V. Nekrasov, B. N. Skvortsov: Second-order Doppler-free spectroscopy. Appl. Phys. B 52, 63–66 (1991)CrossRefADSGoogle Scholar
  4. 4.
    J. C. Bergquist, W. M. Itano, F. Elsner, M. G. Raizen, D. J. Wineland: Single ion optical spectroscopy. In: Light Induced Kinetic Effects on Atoms, Ions and Molecules, L. Moi, S. Gozzini, C. Gabbanini, E. Arimondo, F. Strumia (Eds.) (ETS editrice, Pisa 1991)Google Scholar
  5. 5.
    D. J. Wineland, J. J. Bollinger, W. M. Itano, D. J. Heinzen: Squeezed atomic states and projection noise in spectroscopy. Phys. Rev. A 50, 67–88 (1994)CrossRefADSGoogle Scholar
  6. 6.
    S. Gerstenkorn, P. Luc: Atlas du spectre d’absorption de la molécule d’iode. Technical report, Laboratoire AIMÉ-COTTON CNRS II, Centre National de la Recherche Scientifique, Paris (1978)Google Scholar
  7. 7.
    G. Camy, C. J. Bordé, M. Ducloy: Heterodyne saturation spectroscopy through frequency modulation of the saturating beam. Opt. Commun. 41, 325–330 (1982)CrossRefADSGoogle Scholar
  8. 8.
    P. A. Jungner, M. Eickhoff, S. D. Swartz, Y. Je, J. L. Hall, S. Waltman: Stability and absolute frequency of molecular iodine transitions near 532 nm. Proc. SPIE 2378, 22–34 (1995)ADSGoogle Scholar
  9. 9.
    G. C. Bjorklund: Frequency-modulation spectroscopy: a new method for measuring weak absorptions and dispersions. Opt. Lett. 5, 15–17 (1980)ADSCrossRefGoogle Scholar
  10. 10.
    J. L. Hall, L. Hollberg, T. Baer, H. G. Robinson: Optical heterodyne saturation spectroscopy. Appl. Phys. Lett. 39, 680–682 (1981)CrossRefADSGoogle Scholar
  11. 11.
    P. Cordiale, G. Galzerano, H. Schnatz: International comparison of two iodine-stabilized frequency-doubled Nd:YAG lasers at λ = 532 nm. Metrologia (2000) in pressGoogle Scholar
  12. 12.
    Y. Millerioux, D. Touahri, L. Hilico, A. Clairon, R. Felder, F. Biraben, B. de Beauvoir: Towards an accurate frequency standard at λ = 778 nm using a laser diode stabilized on a hyperfine component of the Doppler-free two-photon transitions in rubidium. Opt. Commun. 108, 91–96 (1994)CrossRefADSGoogle Scholar
  13. 13.
    J. L. Hall, J. Ye, L.-S. Ma, S. Swartz, P. Jungner: Optical frequency standards-some improvements, some measurements, and some dreams. In: Proc. 5th Symposium on Frequency Standards and Metrology, J. Bergquist (Ed.) (World Scientific, Singapore, 1996)pp. 267–276Google Scholar
  14. 14.
    B. de Beauvoir, F. Nez, L. Julien, B. Cagnac, F. Biraben, D. Touahri, L. Hilico, O. Acef, A. Clairon, J. Zondy: Absolute frequency measurement of the 2S —8S/D transitions in hydrogen and deuterium: New determination of the Rydberg constant. Phys. Rev. Lett. 78, 440–443 (1997)CrossRefADSGoogle Scholar
  15. 15.
    D. Touahri, O. Acef, A. Clairon, J.-J. Zondy, R. Felder, L. Hilico, B. de Beauvoir, F. Biraben, F. Nez: Frequency measurement of the 5S1/2 (F = 3)-5D5/2 (F = 5) two-photon transition in rubidium. Opt. Commun. 133, 471–478 (1997)CrossRefADSGoogle Scholar
  16. 16.
    G. Hagel, C. Nesi, L. Jozefowski, C. Schwob, F. Nez, F. Biraben: Accurate measurement of the frequency of the 6S—8S two-photon transition in cesium. Opt. Commun. 160, 1–4 (1999)CrossRefADSGoogle Scholar
  17. 17.
    E. Fretel: Spectroscopie à deux photons d’atomes de rubidium dans un piège magnéto-optique. Ph.D. thesis, Conservatoire National des Arts et Métiers, Paris (1997)Google Scholar
  18. 18.
    1996 OAA Program Committee (Ed.): Optical Amplifiers and Their Applications. Trends Opt. Photon. V (Optical Society of America, Washington,DC 1997)Google Scholar
  19. 19.
    S. Gilbert: Frequency stabilization of a tunable erbium-doped fiber laser. Opt. Lett. 16, 150–152 (1991)ADSGoogle Scholar
  20. 20.
    A. Onae, K. Okomura, Y. Miki, T. Kurosawa, E. Sakuma, J. Yoda, K. Nakagawa: Saturation spectroscopy of an acetylene molecule in the 1550 nm region using an erbium doped fiber amplifier. Opt. Commun. 142, 41–44 (1997)CrossRefADSGoogle Scholar
  21. 21.
    M. de Labachelerie, K. Nakagawa, M. Ohtsu: Ultranarrow 13C2H2 saturated-absorption lines at 1.5 µm. Opt. Lett. 19, 840–842 (1994)ADSCrossRefGoogle Scholar
  22. 22.
    Y. Dancheva, R. Sharma, U. Sterr: Wellenlängenstandards für die optische Telekommunikation bei 1.5 µm. Verhandl. Deutsch. Physikal. Ges., 402 (1999)Google Scholar
  23. 23.
    J. Ye, L.-S. Ma, J. L. Hall: Ultrastable optical frequency reference at 1.064 µm using a C2HD molecular overtone transmission. IEEE Trans. Instrum. Meas. 46, 148–181 (1997)Google Scholar
  24. 24.
    R. W. P. Drever, J. L. Hall, F. V. Kowalski, J. Hough, G. M. Ford, A. J. Munley, H. Ward: Laser phase and frequency stabilization using an optical resonator. Appl. Phys. B 31, 97 (1983)CrossRefADSGoogle Scholar
  25. 25.
    R. L. Barger, J. L. Hall: Pressure shift and broadening of methane line at 3.39 µ studied by laser-saturated molecular absorption. Phys. Rev. Lett. 22, 4–8 (1969)CrossRefADSGoogle Scholar
  26. 26.
    S. N. Bagayev, L. S. Vasilenko, A. K. Dmitriyev, V. G. Gol’dort, B. N. Skvortsov, V. P. Chebotayev: Narrow resonances in radiation spectrum of the He-Ne laser with methane absorber. Appl. Phys. 10, 231–235 (1976)CrossRefADSGoogle Scholar
  27. 27.
    C. O. Weiß, G. Kramer, B. Lipphardt, E. Garcia: Frequency measurement of a CH4 hyperfine line at 88 THz. IEEE J. Quantum Electron. 24, 1970–1972 (1988)CrossRefADSGoogle Scholar
  28. 28.
    G. Kramer, C. O. Weiß, J. Helmcke: Laser frequency stabilization by means of saturation dispersion. Z. Naturforsch. 30 a, 1128–1132 (1975)ADSGoogle Scholar
  29. 29.
    D. A. Tyurikov, M. A. Gubin, A. S. Shelkovnikov, E. V. Koval’chuk: Accuracy of the computer-controlled laser frequency standard based on resolved hyperfine structure of a methane line. IEEE Trans. Instrum. Meas. 44, 166–169 (1995)CrossRefGoogle Scholar
  30. 30.
    J. L. Hall, C. J. Bordé, K. Uehara: Direct optical resolution of the recoil effect using saturated absorption spectroscopy. Phys. Rev. Lett. 37, 1339–1342 (1976)CrossRefADSGoogle Scholar
  31. 31.
    S. N. Bagayev, A. E. Baklanov, V. P. Chebotayev, A. S. Dychkov: Superhigh resolution spectroscopy in methane with cold molecules. Appl. Phys. B 48, 31–35 (1989)CrossRefADSGoogle Scholar
  32. 32.
    O. N. Kompanets, A. R. Kukudzhanov, V. S. Letokhov, E. L. Michailov: Frequency stabilized CO2-laser using OsO4 saturation resonances. Proc. 2nd Frequency Standards and Metrology Symp., Copper Mountain, USA (National Bureau of Standards, Boulder, CO 1976)pp. 167–186Google Scholar
  33. 33.
    C. Chardonnet, C. J. Bordé: Hyperfine interactions in the ν3 band of osmium tetroxide: Accurate determination of the spin-rotation constant by crossover resonance spectroscopy. J. Mol. Spectrosc. 167, 71–98 (1994)CrossRefADSGoogle Scholar
  34. 34.
    O. Acef: CO2/OsO4 lasers as frequency standards in the 29 THz range. IEEE Trans. Instrum. Meas. 46, 162–165 (1997)CrossRefGoogle Scholar
  35. 35.
    A. Godone, M. P. Sassi, E. Bava: High-accuracy capabilities of an OsO4 molecular-beam frequency standard. Metrologia 26, 1–8 (1989)CrossRefADSGoogle Scholar
  36. 36.
    K. Stoll: Perspektiven für ein OsO4 Frequenznormal. PTB—Bericht PTB—Opt—49(Physikalisch-Technische Bundesanstalt, Braunschweig, Germany 1995)Google Scholar
  37. 37.
    N. Ramsey: A molecular beam resonance method with separated oscillating fields. Phys. Rev. 78, 695–699 (1950)CrossRefADSGoogle Scholar
  38. 38.
    G. Kramer, C. O. Weiß, B. Lipphardt: Coherent frequency measurements of the hfs-resolved methane line. In: Frequency Standards and Metrology, A. D. Marchi (Ed.) (Springer, Heidelberg, Berlin 1989)pp. 181–186Google Scholar
  39. 39.
    Y. V. Baklanov, B. Y. Dubetsky, V. P. Chebotayev: Non-linear Ramsey resonances in the optical region. Appl. Phys. 9, 171–173 (1976)CrossRefADSGoogle Scholar
  40. 40.
    C. J. Bordé, C. Salomon, S. Avrillier, A. Van Lerberghe, C. Bréant, D. Bassi, G. Scoles: Optical Ramsey fringes with travelling waves. Phys. Rev. A 30, 1836–1848 (1984)CrossRefADSGoogle Scholar
  41. 41.
    J. L. Hall, M. Zhu, P. Buch: Prospects for using laser-prepared atomic fountains for optical frequency standards applications. J. Opt. Soc. Am. B6, 2194–2205 (1989)ADSCrossRefGoogle Scholar
  42. 42.
    U. Sterr, K. Sengstock, J. H. Müller, D. Bettermann, W. Ertmer: The magnesium Ramsey interferometer: Applications and prospects. Appl. Phys. B 54, 341–346 (1992)CrossRefADSGoogle Scholar
  43. 43.
    A. Celikov, P. Kersten, F. Riehle, G. Zinner, L. D’Evelyn, A. Zibrov, V. L. Velichansky, J. Helmcke: External cavity diode laser high resolution spectroscopy of the Ca and Sr intercombination lines for the development of a transportable frequency/length standard. IEEE Int. Freq. Control Symp. Proc. 39, 153–160 (1985)Google Scholar
  44. 44.
    G. M. Tino, M. Barsanti, M. de Angelis, L. Gianfrani, M. Inguscio: Spectroscopy on the 689 nm intercombination line of Strontium using an extended-cavity InGaP/InGaAlP diode laser. Appl. Phys. B 55, 397–400 (1992)CrossRefADSGoogle Scholar
  45. 45.
    A. M. Akulshin, A. Celikov, V. L. Velichansky: Nonlinear Doppler-free spectroscopy of the 61S0-63P1 intercombination transition in barium. Opt. Commun. 93, 54–58 (1992)CrossRefADSGoogle Scholar
  46. 46.
    R. L. Barger, J. C. Bergquist, T. C. English, D. J. Glaze: Resolution of photon-recoil structure of the 6573-Å calcium line in an atomic beam with optical Ramsey fringes. Appl. Phys. Lett. 34, 850–852 (1979)CrossRefADSGoogle Scholar
  47. 47.
    R. L. Barger: Influence of second-order Doppler effect on optical Ramsey fringe profiles. Opt. Lett. 6, 145–147 (1981)ADSCrossRefGoogle Scholar
  48. 48.
    A. Morinaga, F. Riehle, J. Ishikawa, J. Helmcke: A Ca optical frequency standard: Frequency stabilization by means of nonlinear Ramsey resonances. Appl. Phys. B 48, 165–171 (1989)CrossRefADSGoogle Scholar
  49. 49.
    P. Kersten, F. Mensing, U. Sterr, F. Riehle: A transportable optical calcium frequency standard. Appl. Phys. B 68, 27–38 (1999)CrossRefADSGoogle Scholar
  50. 50.
    N. Ito, J. Ishikawa, A. Morinaga: Frequency locking a dye laser to the central optical Ramsey fringe in a Ca atomic beam and wavelength measurement. J. Opt. Soc. Am. B 8, 1388–1390 (1991)ADSCrossRefGoogle Scholar
  51. 51.
    N. Ito, J. Ishikawa, A. Morinaga: Evaluation of the optical phase shift in a Ca Ramsey fringe stabilized optical frequency standard by means of laser-beam reversal. Opt. Commun. 109, 414–421 (1994)CrossRefADSGoogle Scholar
  52. 52.
    A. S. Zibrov, R. W. Fox, R. Ellingsen, C. S. Weimer, V. L. Velichansky, G. M. Tino, L. Hollberg: High-resolution diode-laser spectroscopy of calcium. Appl. Phys. B 59, 327–331 (1994)CrossRefADSGoogle Scholar
  53. 53.
    A. M. Akulshin, K. Nakagawa, M. Ohtsu: Frequency chain towards the Ca intercombination line based on laser diodes: First step. Appl. Phys. B 58, 529–532 (1994)CrossRefADSGoogle Scholar
  54. 54.
    G. Brida, F. Bertinetto: Preliminary steps in Ca spectroscopy. In: Proc. 5th Symp. on Frequency Standards and Metrology, J. C. Bergquist (Ed.) (World Scientific, Singapore 1996)pp. 441–442Google Scholar
  55. 55.
    W.-L. Yang, Y.-P. Yang, H.-C. Huang, K.-M. Chang, M.-S. Huang, J.-T. Shy: Development of a portable optical frequency standard with a small Ca cell. In: Conf. Digest of the Conf. on Precision Electromagnetic Measurements, No. 08855-1331, A. Braun (Ed.) (IEEE Service Center, Piscataway, NJ 1996) CPEM pages 88–89Google Scholar
  56. 56.
    C. J. Bordé, S. Avrillier, A. Van Lerberghe, C. Salomon, D. Bassi, G. Scoles: Observation of optical Ramsey fringes in the 10 µm spectral region using a supersonic beam of SF6. In: Third Symposium on Frequency Standards and Metrology, Aussois, 1981, J. Phys. (Paris), Colloque C-8, Suppl. 12, C8-15–C8-19 (1981)Google Scholar
  57. 57.
    G. Camy, N. Courtier, J. Helmcke: Single recoil component optical Ramsey fringes at 514.5 nm in an I2 supersonic beam. In: Laser Spectroscopy VIII, W. Persson, S. Svanberg (Eds.) (Springer, Heidelberg, Berlin 1987)pp. 386–387Google Scholar
  58. 58.
    A. Huber, B. Gross, M. Weitz, T. W. Hänsch: High-resolution spectroscopy of the 1S-2S transition in atomic hydrogen. Phys. Rev. A 59, 1844–1851 (1999)CrossRefADSGoogle Scholar
  59. 59.
    B. Gross, A. Huber, M. Niering, M. Weitz, T. W. Hänsch: Optical Ramsey spectroscopy of atomic hydrogen. Europhys. Lett. 44, 186–191 (1998)CrossRefADSGoogle Scholar
  60. 60.
    F. Schmidt-Kaler, D. Leibfried, S. Seel, C. Zimmermann, W. König, M. Weitz, T. W. Hänsch: High-resolution spectroscopy of the 1S-2S transition of atomic hydrogen and deuterium. Phys. Rev. A 51, 2789–2800 (1995)CrossRefADSGoogle Scholar
  61. 61.
    S. L. Rolston, W. D. Phillips: Laser-cooled neutral atom frequency standards. Proc. IEEE 79, 943–951 (1991)CrossRefADSGoogle Scholar
  62. 62.
    M. Walhout, U. Sterr, A. Witte, S.-L. Rolston: Lifetime of the metastable 6s [1/2]0 clock state in xenon. Opt. Lett. 20, 1192–1194 (1995)ADSCrossRefGoogle Scholar
  63. 63.
    W. Ertmer, R. Blatt, J. L. Hall: Some candidate atoms and ions for frequency standards research using laser radiative cooling techniques. In: Laser Cooled and Trapped Atoms, W. D. Phillips (Ed.) (Nat. Bur. Stand. Spec. Pub., Vol. 653 (NBS, Reading, MA 1983)pp. 154–161Google Scholar
  64. 64.
    T. Badr, S. Guérandel, M. D. Plimmer, P. Juncar, M. E. Himbert: Two-photon spectroscopy of the 4d105s 2S1/2 → 4d95s2 2D5/2 transition in atomic silver: a promising optical frequency standard. In: Book of Abstracts 6th EPS Conference on Atomic and Molecular Physics (ECAMP 94), Vol 22D, C. Biancalana, P. Bicchi, E. Mariotti (Eds.) (European Physical Society, Strasbourg 1998)pp. 1–6Google Scholar
  65. 65.
    J. Dirscherl, H. Walther: Towards a silver frequency standard. In: Digest of the 14th International Conference on Atomic Physics (ICAP 94), Boulder,CO (1994)Poster 1H3Google Scholar
  66. 66.
    N. Beverini, E. Maccioni, D. Pereira, F. Strumia, G. Vissani: Production of low-velocity Mg and Ca atomic beams by laser light pressure. In: 5th Italian Conference on Quantum Electronics and Plasma Physics, G. C. Righini (Ed.) (Italian Physical Society, Bologna 1988)pp. 205–211Google Scholar
  67. 67.
    T. Kurosu, F. Shimizu: Laser cooling and trapping of Alkaline Earth atoms. Jpn. J. Appl. Phys. 31, 908–912 (1992)CrossRefADSGoogle Scholar
  68. 68.
    F. Ruschewitz, J. L. Peng, H. Hinderthür, N. Schaffrath, K. Sengstock, W. Ertmer: Sub-kilohertz optical spectroscopy with a time domain atom interferometer. Phys. Rev. Lett. 80, 3173–3176 (1998)CrossRefADSGoogle Scholar
  69. 69.
    T. P. Dinneen, K. R. Vogel, E. Arimondo, J. L. Hall, A. Gallagher: Cold collisions of Sr*-Sr in a magneto-optical trap. Phys. Rev. A 59, 1216–1222 (1999)CrossRefADSGoogle Scholar
  70. 70.
    H. Katori, T. Ido, Y. Isoya, M. Kuwata-Gonokami: Magneto-optical trapping and cooling of strontium atoms down to the photon recoil temperature. Phys. Rev. Lett. 82, 1116–1119 (1999)CrossRefADSGoogle Scholar
  71. 71.
    G. Zinner: Ein optisches Frequenznormal auf der Basis lasergekühlter Calciumatome. PTB-Bericht PTB-Opt-58 (Physikalisch-Technische Bundesanstalt, Braunschweig1998)Google Scholar
  72. 72.
    E. L. Raab, M. Prentiss, A. Cable, S. Chu, D. E. Pritchard: Trapping of neutral sodium atoms with radiation pressure. Phys. Rev. Lett. 59, 2631–2634 (1987)CrossRefADSGoogle Scholar
  73. 73.
    T. Kisters, K. Zeiske, F. Riehle, J. Helmcke: High-resolution spectroscopy with laser-cooled and trapped calcium atoms. Appl. Phys. B 59, 89–98 (1994)CrossRefADSGoogle Scholar
  74. 74.
    A. Witte, T. Kisters, F. Riehle, J. Helmcke: Laser cooling and deflection of a calcium atomic beam. J. Opt. Soc. Am. B 9, 1030–1037 (1992)ADSCrossRefGoogle Scholar
  75. 75.
    W. D. Phillips, H. Metcalf: Laser deceleration of an atomic beam. Phys. Rev. Lett. 48, 596–599 (1982)CrossRefADSGoogle Scholar
  76. 76.
    B. P. Anderson, M. A. Kasevich: Enhanced loading of a magneto-optic trap from an atomic beam. Phys. Rev. A 50, R3581–3584 (1994)CrossRefADSGoogle Scholar
  77. 77.
    J. Helmcke, J. J. Snyder, A. Morinaga, F. Mensing, M. Gläser: New ultra-high resolution dye laser spectrometer utilizing a non-tunable reference resonator. Appl. Phys. 43, 85–91 (1987)Google Scholar
  78. 78.
    V. Vassiliev, V. Velichansky, P. Kersten, T. Trebst, F. Riehle: Subkilohertz enhanced-power diode-laser spectrometer in the visible. Opt. Lett. 23, 1229–1231 (1998)ADSCrossRefGoogle Scholar
  79. 79.
    O. S. Brozek, V. Quetschke, A. Wicht, K. Danzmann: Highly efficient cw frequency doubling of 854 nm GaAlAs diode lasers in an external ring cavity. Opt. Commun. 146, 141–146 (1998)CrossRefADSGoogle Scholar
  80. 80.
    C. J. Bordé: Atomic interferometry with internal state labelling. Phys. Lett. A 140, 10–12 (1989)CrossRefADSGoogle Scholar
  81. 81.
    H. Hinderthür, F. Ruschewitz, H.-J. Lohe, S. Lechte, K. Sengstock, W. Ertmer: Time-domain high-finesse atom interferometry. Phys. Rev. A 59, 2216–2219 (1999)CrossRefADSGoogle Scholar
  82. 82.
    A. Clairon, S. Ghezali, G. Santarelli, P. Laurent, S. N. Lea, M. Bahoura, E. Simon, S. Weyers, K. Szymaniec: Preliminary accuracy evaluation of a cesium fountain frequency standard. In: Proc. 5th Symposium on Frequency Standards and Metrology, J. Bergquist (Ed.) (World Scientific, Singapore 1996)pp. 44–59Google Scholar
  83. 83.
    E. Simon, P. Laurent, A. Clairon: Measurement of the Stark shift of the Cs hyperfine splitting in an atomic fountain. Phys. Rev. A 57, 436–439 (1998)CrossRefADSGoogle Scholar
  84. 84.
    R. G. Beausoleil, T. W. Hänsch: Ultrahigh-resolution two-photon optical Ramsey spectroscopy of an atomic fountain. Phys. Rev. A 33, 1661–1670 (1986)CrossRefADSGoogle Scholar
  85. 85.
    H. Wallis, W. Ertmer: Broadband laser cooling on narrow transitions. J. Opt. Soc. Am. B6, 2211 (1989)ADSGoogle Scholar
  86. 86.
    K. R. Vogel, T. P. Dinneen, A. Gallagher, J. L. Hall: Narrow line cooling of strontium to the recoil limit. In: Conf. Digest of the Conf. on Precision Electromagnetic Measurements, T. L. Nelson (Ed.) (IEEE Service center, Piscataway,NJ 1998)Google Scholar
  87. 87.
    G. Kramer, B. Lipphardt, C. O. Weiss: Coherent frequency synthesis in the infrared. IEEE Freq. Control Symp. Proc. 46, 39–43 (1992)CrossRefGoogle Scholar
  88. 88.
    H. Schnatz, B. Lipphardt, J. Helmcke, F. Riehle, G. Zinner: First phase-coherent frequency measurement of visible radiation. Phys. Rev. Lett. 76, 18–21 (1996)CrossRefADSGoogle Scholar
  89. 89.
    H. R. Telle: Absolute measurement of optical frequencies. In: Frequency Control of Semiconductor Lasers, M. Ohtsu (Ed.) (Wiley, New York 1996)pp. 137–172Google Scholar
  90. 90.
    F. Riehle, H. Schnatz, B. Lipphardt, P. Kersten, T. Trebst, G. Zinner, J. Helmcke: Optical Calcium Frequency-Standard: Status and Prospects. In: Frequency Standards Based on Laser-Manipulated Atoms and Ions, PTB-Bericht, PTB-Opt-51, J. Helmcke, S. Penselin (Eds.) (Physikalisch-Technische Bundesanstalt Braunschweig 1996)pp. 11–20Google Scholar
  91. 91.
    F. Riehle, J. Ishikawa, J. Helmcke: Suppression of a recoil component in nonlinear Doppler-free spectroscopy. Phys. Rev. Lett. 61, 2092–2095 (1988)CrossRefADSGoogle Scholar
  92. 92.
    F. Riehle, T. Kisters, A. Witte, J. Helmcke: Matter wave interferometry with Ca atoms. In: Laser Spectroscopy, M. Ducloy, E. Giacobino, G. Camy (Eds.) (World Scientific, Singapore 1992)pp. 246–251Google Scholar
  93. 93.
    T. Kurosu, A. Morinaga: Suppression of the high-frequency recoil component in optical Ramsey-fringe spectroscopy. Phys. Rev. A 45, 4799–4802 (1992)CrossRefADSGoogle Scholar
  94. 94.
    F. E. Dingler, V. Rieger, K. Sengstock, U. Sterr, W. Ertmer: Excitation of only a single recoil component in optical Ramsey interferometry using cross-over resonances. Opt. Commun. 110, 99–104 (1994)CrossRefADSGoogle Scholar
  95. 95.
    T. Kurosu, G. Zinner, T. Trebst, F. Riehle: Method for quantum-limited detection of narrow-linewidth transitions in cold atomic ensembles. Phys. Rev. A 58, R4275–R4278 (1998)CrossRefADSGoogle Scholar
  96. 96.
    A. Huber, T. Udem, B. Gross, J. Reichert, M. Kourogi, K. Pachucki, M. Weitz, T. W. Hänsch: Hydrogen—deuterium 1S-2S isotope shift and the structure of the deuteron. Phys. Rev. Lett. 80, 468–471 (1998)CrossRefADSGoogle Scholar
  97. 97.
    B. Bodermann, M. Klug, H. Knöckel, E. Tiemann, T. Trebst, H. R. Telle: Frequency measurement of I2 lines in the NIR using Ca and CH4 optical frequency standards. Appl. Phys. B 67, 95–99 (1998)CrossRefADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Fritz Riehle
    • 1
  • Jürgen Helmcke
    • 1
  1. 1.Physikalisch-Technische Bundesanstalt (PTB)BraunschweigGermany

Personalised recommendations