Using recently developed quantum wave function techniques, we have performed a simulation of $^{85}\mathrm{Rb}$ atoms in a one-dimensional optical molasses, formed from counterpropagating laser beams with orthogonal linear polarizations. Both internal and external degrees of freedom are treated quantum mechanically in one dimension and the spectrum of resonance fluorescence is calculated and compared to recent experiments. Excellent agreement is obtained for the spectrum and additional insight is gained into the experimental evidence for quantized motion in the optical potentials.Using recently developed quantum wave function techniques, we have performed a simulation of $^{85}\mathrm{Rb}$ atoms in a one-dimensional optical molasses, formed from counterpropagating laser beams with orthogonal linear polarizations. Both internal and external degrees of freedom are treated quantum mechanically in one dimension and the spectrum of resonance fluorescence is calculated and compared to recent experiments. Excellent agreement is obtained for the spectrum and additional insight is gained into the experimental evidence for quantized motion in the optical potentials.

Physical Review LettersAug 30, 199372 citations

Fluorescence spectrum of ultracold optical molasses

Richard N. Watts, Paul D. Lett, William D. Phillips +3 more

Early experiments on ultracold optical molasses relied on time-of-flight and other ballistic techniques to measure the temperature of atoms released from the molasses.1,2 At the extremely low temperatures observed, the size of the molasses, the effects of gravity, the probe that detected the falling atoms, and the way in which the laser beams forming the molasses were turned off produced a large systematic uncertainty in the temperature determination. Here, we report a direct measurement of the Doppler width of the fluorescence spectrum of Na atoms still viscously confined in the molasses. We determined this spectrum using an optical heterodyne technique and we believe this to be the first time an atomic fluorescence spectrum has been heterodyned. The temperature deduced from the Doppler width is in good agreement with that determined using improved time-of-flight techniques. The heterodyne technique has the added advantage of providing spatially resolved temperature measurements. In addition to the nominally 600-kHz wide Doppler peak, we see a much narrower (60-kHz wide) peak which we tentatively ascribe to Dicke narrowing due to confinement by optical forces.Early experiments on ultracold optical molasses relied on time-of-flight and other ballistic techniques to measure the temperature of atoms released from the molasses.1,2 At the extremely low temperatures observed, the size of the molasses, the effects of gravity, the probe that detected the falling atoms, and the way in which the laser beams forming the molasses were turned off produced a large systematic uncertainty in the temperature determination. Here, we report a direct measurement of the Doppler width of the fluorescence spectrum of Na atoms still viscously confined in the molasses. We determined this spectrum using an optical heterodyne technique and we believe this to be the first time an atomic fluorescence spectrum has been heterodyned. The temperature deduced from the Doppler width is in good agreement with that determined using improved time-of-flight techniques. The heterodyne technique has the added advantage of providing spatially resolved temperature measurements. In addition to the nominally 600-kHz wide Doppler peak, we see a much narrower (60-kHz wide) peak which we tentatively ascribe to Dicke narrowing due to confinement by optical forces.

Annual Meeting Optical Society of AmericaJan 1, 19890 citations

Using recently developed quantum wave function techniques, we have performed a simulation of

^{85}\mathrm{Rb}

atoms in a one-dimensional optical molasses, formed from counterpropagating laser beams with orthogonal linear polarizations. Both internal and external degrees of freedom are treated quantum mechanically in one dimension and the spectrum of resonance fluorescence is calculated and compared to recent experiments. Excellent agreement is obtained for the spectrum and additional insight is gained into the experimental evidence for quantized motion in the optical potentials.