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41
Sep 19, 2013
09/13
by
Gaëtan Hagel; Marie Houssin; Martina Knoop; Caroline Champenois; Michel Vedel; Fernande Vedel
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To obtain a high degree of long-term length stabilisation of an optical reference cavity, its free-spectral range is locked by means of an accurate and stable frequency synthesizer. The locking scheme is twofold: a laser is locked on the N$^{th}$ mode of a reference Fabry-Perot cavity and part of the laser light is shifted in frequency to be in resonance with the (N+1)$^{th}$ mode of the cavity. This shift is generated by an acousto-optical modulator (AOM) mounted in a double-pass scheme,...
Source: http://arxiv.org/abs/physics/0507208v2
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42
Sep 23, 2013
09/13
by
Caroline Champenois; Martina Knoop; Marie Houssin; Gaëtan Hagel; Michel Vedel; Fernande Vedel
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A recent evaluation of the frequency uncertainty expected for an optical frequency standard based on a single trapped $^{43}$Ca$^+$ ion was published in Phys. Rev. A {\bf 72} (2005) 043404. The paper contains some interesting information like systematic frequency shifts but fails to depict their uncertainty, leading to confuse accuracy and precision. The conclusions about the major contribution to the frequency shift are not consistent with the presented calculations and omit comparisons with...
Source: http://arxiv.org/abs/physics/0511089v1
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53
Sep 18, 2013
09/13
by
Caroline Champenois; Gaetan Hagel; Marie Houssin; Martina Knoop; Cedric Zumsteg; Fernande Vedel
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A scheme for a THz frequency standard based on three-photon coherent population trapping in stored ions is proposed. Assuming the propagation directions of the three lasers obey the phase matching condition, we show that stability of few 10$^{-14}$ at one second can be reached with a precision limited by power broadening to $10^{-11}$ in the less favorable case. The referenced THz signal can be propagated over long distances, the useful information being carried by the relative frequency of the...
Source: http://arxiv.org/abs/0705.3565v1
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41
Sep 23, 2013
09/13
by
Caroline Champenois; Gaetan Hagel; Martina Knoop; Marie Houssin; Cedric Zumsteg; Fernande Vedel; Michael Drewsen
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Doppler laser cooling of a three-level ladder system using two near-resonant laser fields is analyzed in the case of the intermediate level being metastable while the upper level is short-lived. Analytical as well as numerical results for e.g. obtainable scattering rates and achievable temperatures are presented. When appropriate, comparisons with two-level single photon Doppler laser cooling is made. These results are relevant to recent experimental Doppler laser cooling investigations...
Source: http://arxiv.org/abs/0710.5078v2
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49
Sep 22, 2013
09/13
by
Martina Knoop; Caroline Champenois; Gaëtan Hagel; Marie Houssin; Caroline Lisowski; Michel Vedel; Fernande Vedel
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The lifetime of the 3d^2D_5/2-level in singly-ionized calcium has been measured by the electron-shelving technique on different samples of rf trapped ions. The metastable state has been directly populated by exciting the dipole-forbidden 4S_1/2 - 3D_5/2 transition. In ion clouds, the natural lifetime of this metastable level has been measured to be (1095+-27) ms. For the single-ion case, we determined a lifetime of (1152+-20) ms. The 1sigma-error bars at the 2%-level have different origins for...
Source: http://arxiv.org/abs/physics/0309094v3
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61
Sep 23, 2013
09/13
by
Caroline Champenois; Marie Houssin; Caroline Lisowski; Martina Knoop; Gaetan Hagel; Michel Vedel; Fernande Vedel
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We numerically evaluate the expected performances of an optical frequency standard at 729 nm based on a single calcium ion. The frequency stability is studied through the Allan deviation and its dependence on the excitation method (single Rabi pulse or two Ramsey pulses schemes) and the laser linewidth are discussed. The minimum Allan deviation that can be expected is estimated to $\sigma_y(\tau) \approx 2.5\times 10^{-15}/\sqrt{\tau}$ with $\tau$ the integration time. The frequency shifts...
Source: http://arxiv.org/abs/physics/0312120v2
