Optogalvanic nonlinear hanle effect by a single frequency laser: A quantitative analysis

Beverini, N.; Ernst, K.; Inguscio, M.; Strumia, F.

doi:10.1007/bf00691688

Cited by 13 publications

(3 citation statements)

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“…Due to the saturation, this can be observed in the upper as well in the lower level of the optical transition. The method of nonlinear level crossing was used, for example, to study relaxation times [16], saturation and pressure broadening parameters [17], hyperfine structure [16] or Ramsey-like fringes by means of two separate interactions of the laser with the atoms [18]. For a detailed theoretical analysis of the nonlinear level crossing the reader is referred to [16,19].…”

Section: Introductionmentioning

confidence: 99%

Stark effect study of the 4f66s2 7 F 1, 2, 3, 4, 5, 6 levels of samarium using nonlinear level crossing technique

Rinkleff

Steudel

Zeiske

1991

Z Phys D - Atoms, Molecules and Clusters

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Abstract. The nonlinear level crossing technique withparallel electric and magnetic fields was used to investigate the Stark effect of six levels of the ground multiplet 4f 66 s 2 7F in the Sm I-spectrum. The tensor polarizabitities were deduced from the level crossing signals. The variation of the tensor polarizabilities of the levels of the ground multiplet is well reproduced by the LS coupling approximation, which gives an average value of c~2(F ) = -0.88(6) kHz/(kV/cm) 2 for the six measured levels. The experimental results confirm the validity of the central field approximation in the ground configuration of Sm.

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Section: Introductionmentioning

confidence: 99%

Stark effect study of the 4f66s2 7 F 1, 2, 3, 4, 5, 6 levels of samarium using nonlinear level crossing technique

Rinkleff

Steudel

Zeiske

1991

Z Phys D - Atoms, Molecules and Clusters

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“…These conditions allow the existence of a dark state that will disappear for increasing magnetic field, as soon as the Zeeman splitting is larger than the CPT resonance linewidth. This effect is known as the non-linear Hanle effect [18]. An example of full density matrix numerical calculation is reported in [19].…”

Section: Pacs Numbersmentioning

confidence: 99%

Doppler-free spectroscopy on the Cs D_1 line with a dual-frequency laser

et al. 2016

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We report on Doppler-free laser spectroscopy in a Cs vapor cell using a dual-frequency laser system tuned on the Cs D1 line. Using counter-propagating beams with crossed linear polarizations, an original sign-reversal of the usual saturated absorption dip and large increase in Doppler-free atomic absorption is observed. This phenomenon is explained by coherent population trapping (CPT) effects. The impact of laser intensity and light polarization on absorption profiles is reported in both single-frequency and dual-frequency regimes. In the latter, frequency stabilization of two diode lasers was performed, yielding a beat-note fractional frequency stability at the level of 3 × 10 −12 at 1 s averaging time. These performances are about an order of magnitude better than those obtained using a conventional single-frequency saturated absorption scheme. PACS numbers:In gas cell experiments, saturated absorption spectroscopy or Doppler-free spectroscopy [1,2] is an elegant technique to circumvent Doppler broadening and to allow the detection of natural-linewidth resonance dips in the bottom of absorption profiles. This method, frequently used to stabilize the frequency of a laser to a particular atomic line, is applied in atomic frequency standards [3], magnetometers [4], laser-cooling experiments [5] or atom interferometry. Laser fractional frequency stability in the 10 −13 −10 −11 range at 1 s integration time can be obtained by combining saturated absorption techniques and narrow-linewidth diode lasers [6][7][8][9][10]. In a common saturated absorption scheme, two counter-propagating laser beams of same frequency, a pump-beam and a probe beam, derived from a single laser beam, overlap one another in an atomic vapor cell. Since both beams have the same frequency, the Doppler effect brings different velocity groups into resonance with each beam. On resonance, only atoms presenting zero velocity along the light propagation axis actually experience the two beams with the same laser frequency. If the pump-beam intensity is high enough, the ground state is depleted and therefore the absorption of the probe beam is reduced compared to the case without pump beam. In this case, a so-called Lamb dip, with lorentzian profile, appears at the resonance frequency of the atomic transition in the bottom of a gaussian Doppler-broadened absorption profile. The full-width at half maximum (FWHM) of the Dopplerfree Lamb dip can be at low laser intensity as small as the natural linewidth of the atomic transition (4.6 MHz for the Cs D 1 line). This process is relatively easy to understand in the case of a simple two-level atom with a single-frequency laser system. In real experience, alkali atoms exhibit a complex multi-level energy structure with hyperfine structure splitting and numerous Zeeman sub-levels, especially in the Cs case (see Fig. 1). Such multi-level structures can lead, under appropriate conditions, to a sign reversal of saturation resonances [11][12][13].In the present article, we report on a Doppler-free laser frequency s...

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“…where BUM is the fitted half width at half maximum of both functions (Beverini et al 1985). The Lorentzian gives the width of the upper level and the Gaussian gives the Doppler width.…”

Section: 49and002mentioning

confidence: 99%