Browsing by Author "Yu, IA"

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Adomian's decomposition method for electromagnetically induced transparency
(2005-12-01)
Kao, YM
;
Jiang, TF
;
Yu, IA
;
應用數學系
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物理研究所
We developed the Adomian's decomposition method to work for the electromagnetically induced transparency (EIT) problem. The method is general and capable to solve the coupled nonlinear partial differential equations for a light pulse passing through a three-level Lambda-type coherent medium. This EIT system is described by the coupled Maxwell-Schrodinger equations and optical Bloch equations. In the weak probe field case, the results agree with perturbation solutions and experimental data. In the stronger probe field case while perturbation may fail, our results reproduce experimental data well. With the techniques of spatial and time partitions, we extend the decomposition method that will be versatile for the investigation of the light pulse propagating through a coherent atomic medium.
Cooling atoms below 100 mu K
(2000-04-01)
Tung, SK
;
Chen, YC
;
Lin, CW
;
Hsu, L
;
Yu, IA
We capture Rb-87 atoms from room-temperature background vapor with a magneto-optical trap (MOT). The temperature of the atoms in the MOT is 320 mu K as the result of Doppler cooling. We further employ polarization gradient cooling to lower atom temperature. The factors that can affect the performance of polarization gradient cooling have been systematically studied. An atom temperature of 75 mu K has been reached with the optimized conditions. Temperatures are measured by the release and recapture method and the time of flight method. Such cold atoms are ready for the evaporative cooling which will finally realize the Bose-Einstein condensation.
Effect of the trapping laser linewidth on the atom number in a magneto-optical trap
(2000-10-01)
Chen, YC
;
Lin, WB
;
Hsue, HC
;
Hsu, L
;
Yu, IA
We have experimentally studied the effect of the trapping laser linewidth on the number of capped atoms in a magneto-optical trap (MOT). Our data show that a significant number of the atoms can still be trapped in the MOT, even when the trapping laser linewidth is larger than the natural linewidth of the excited state of the driving transition.
Simple technique for directly and accurately measuring the number of atoms in a magneto-optical trap
(2001-09-01)
Chen, YC
;
Liao, YA
;
Hsu, L
;
Yu, IA
;
電子物理學系
We have systematically studied a simple technique that accurately determines number of atoms in a magneto-optical trap, Absorption energy of a laser field that interacts with cold atoms is a direct measurement of atom number. The measured energy neither depends on the detuning, intensity, and polarization of the laser field nor is affected by other system parameters. Our work also demonstrates that such technique can be applied to study the phenomenon of coherent population trapping.