In: Physical Review A, 2006, vol. 74, p. 032504
We present experimental and theoretical studies of the absorption, emission, and photodissociation spectra of Rb₂ molecules in solid helium. We have identified 11 absorption bands of Rb₂. All laser-excited molecular states are quenched by the interaction with the He matrix. The quenching results in efficient population of a metastable (1) ³πu state, which emits...
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In: Physical Review A, 2006, vol. 74, p. 032509
We report the observation of emission spectra from Rb*Hen exciplexes in solid ⁴He. Two different excitation channels were experimentally identified, viz., exciplex formation via laser excitation to the atomic 5P3/2 and to the 5P1/2 levels. While the former channel was observed before in liquid helium, on helium nanodroplets, and...
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In: The European Physical Journal: Applied Physics, 2006, vol. 33, p. 221-224
For physical processes which express themselves as a frequency, for example magnetic field measurements using optically-pumped alkali-vapor magnetometers, the precise extraction of the frequency from the noisy signal is a classical problem. We describe herein a frequency measurement system based on an inexpensive commercially available computer sound card coupled with a software single-tone...
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In: The European Physical Journal D, 2006, vol. 38, no. 2, p. 239-247
We discuss the design and performance of a laser-pumped cesium vapor magnetometer in the Mx configuration. The device will be employed in the control and stabilization of fluctuating magnetic fields and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. We have determined the intrinsic sensitivity of the device to be 15 fT in a 1 Hz...
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In: Journal of Chemical Physics, 2006, vol. 124, p. 024511
We present a theoretical and experimental study of the laser-induced formation process and of the emission spectra of Cs*Hen exciplexes in the hcp and bcc phases of solid helium. Two different exciplex molecules are detected: a linear triatomic Cs*He₂, which can exist in two electronic states: Aπ1/2 and Bπ3/2, and a...
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In: Journal of Research of the National Institute of Standards and Technology, 2005, vol. 110, p. 179-183
We designed laser-pumped cesium vapor magnetometers in the Mx configuration for the control and stabilization of magnetic field fluctuations and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. The intrinsic sensitivity of the device was determined to be 30 fT in a measurement bandwidth of 1 Hz, limited by laser noise. In the shot noise...
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In: Applied Physics B: Lasers and Optics, 2005, vol. 80(6), p. 645 - 654
We have performed a comparison of laser (LsOPM) and lamp (LpOPM) pumped cesium vapor magnetometers. Although the LsOPM operated 50% above its shot- noise limit we found an intrinsic sensitivity of 15 fT/√Hz and 25 fT/√Hz for the LsOPM and the LpOPM, respectively. Two modes of operation, viz. the phase-stabilized and the self-oscillating modes, were investigated and found to yield a similar...
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In: Physical Review Letters, 2005, vol. 94, p. 063001
We have observed several new spectral features in the fluorescence of cesium atoms implanted in the hcp phase of solid helium following laser excitation to the 6²P states. Based on calculations of the emission spectra using semi empirical Cs-He pair potentials the newly discovered lines can be assigned to the decay of specific Cs*He(n) exciplexes: an apple-shaped Cs(AП(3/2))He₂ and a...
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In: Journal of the Optical Society of America: B, 2005, vol. 22 No. 1, p. 77-87
Cardiomagnetometry is a growing field of noninvasive medical diagnostics that has triggered a need for affordable high-sensitivity magnetometers. Optical pumping magnetometers (OPMs) are promising candidates for satisfying that need since it has been demonstrated that they can be used to map the magnetic field of the beating human heart. We discuss the principle of a phase-detecting OPM and...
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In: Optics and Lasers in Engineering, 2005, vol. 43, p. 387-401
In this paper we review research done by the recently founded Fribourg group for Atomic Physics (FRAP) using laser-assisted spin coherence spectroscopy of atomic samples in applied and fundamental physics. Spin coherence in optically pumped ensembles of paramagnetic atoms may be extremely long-lived when the samples are well shielded from external perturbations, like static or oscillating...
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