Doppler laser cooled

G. Raithel, S. L. Rolston, R. J. C. Spreeuw, and C. I. Westbrook. I also want to remember and acknowledge Richard N. Watts, who died in November 1996 at the age of 39. His pioneering work on laser cooling with diode lasers, sub-Doppler laser cooling and localization of laser cooled atoms prepeired the way for all the subsequent work on optical lattices. 

Doppler laser-cooling is an essential ingredient in the SCSI-MS technique. First, it provides the necessary damping force to cool directly and sympathetically the atomic and molecular ions, respectively, such that a cold and strongly-coupled two-ion system is formed. Second, it gives rise to the fluorescence photons used in the detection process. Third, the radiation pressure force can be modulated to excite the common motion of the ions. 

The position of a laser-cooled ion is measured by imaging the fluorescence light emitted during the Doppler laser-cooling process onto a CCD camera. There are two fundamental factors that limit the resolution the spatial resolution of the imaging system and the finite ion temperature. 

Lett P D, Watts R N, Westbrook C I, Phillips W D, Gould P L and Metcalf H J 1988 Gbservation of atoms, laser-cooled belowthe Doppler limit Phys.Rev.Lett. 61 169-72... 

Dalibard J and Cohen-Tannoudji C 1989 Laser cooling belowthe Doppler limit by polarization gradients simple theoretical models J.Opt.Soc.Am. B 6 2023-45... 

DOPPLER COOLING The first ideas for laser cooling of atoms [6] and ions [7] were published in 1975. The basic idea of what is now called Doppler cooling can be understood by referring to the famous picture. Here we see a typical atomic resonance curve, which we can take to show the rate at which an atom... 

SUB-DOPPUIR COOLING In 1988 the NIST-Gaithersburg group made careful measurements of the temperature of atoms laser cooled in optical molasses, cind found temperatures significantly below the Doppler cooling limit 113). The initial measurements on laser cooled sodium atoms gave temperatures of about 40 pK, about six times lower tham the predicted lower limit of 240 pK. 

Not only can the radiation pressure force lead to ion cooling through the Doppler-effect, but it can be used further to exert a periodic force on the atomic ions. By modulating the intensity of one of the two laser-cooling beams propagating along... 

An alternative method for overcoming the Doppler tuning problem in laser cooling has been demonstrated by Ertmer et al. 52] Instead of using a spatially varying magnetic field these authors controlled the frequency of the laser by means of an electro-optic modulator, driven by a radiofrequency source. Varying the frequency of the r.f. field applied produces sidebands to the laser frequency and these can be swept in step with the Doppler shift. 

J. Dalibard, C. Cohen-Tannoudji, Laser cooling below the Doppler limit by polarization gradients simple theoretical model. J. Opt. Soc. Am. B 6, 2023 (1989) ... 

P.D. Lett, R.N. Walls, Ch. I. Westbrook, W.D. Phillips, P.L. Gould, H.J. Metcalf Observation of atoms laser cooled below the Doppler limit. Phys. Rev. Lett. 61, 169 (1988)... 

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