Difference between revisions of "Light forces"
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* [[Dipole forces and the dressed atom picture]] | * [[Dipole forces and the dressed atom picture]] | ||
** [[Dressed atom approach]] ([https://cua-admin.mit.edu:8443/wiki/images/c/c8/2009-04-17-Dressed_Atoms.pdf 2009 Class notes]) | ** [[Dressed atom approach]] ([https://cua-admin.mit.edu:8443/wiki/images/c/c8/2009-04-17-Dressed_Atoms.pdf 2009 Class notes]) | ||
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** [[Dipole forces within the dressed atom approach]] ([https://cua-admin.mit.edu:8443/wiki/images/b/b8/2009-04-22_Stimulated_forces.pdf 2009 Class notes]) | ** [[Dipole forces within the dressed atom approach]] ([https://cua-admin.mit.edu:8443/wiki/images/b/b8/2009-04-22_Stimulated_forces.pdf 2009 Class notes]) | ||
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[[Category:8.422|5]] | [[Category:8.422|5]] | ||
Revision as of 22:08, 24 April 2009
This chapter introduces the interaction of motional degrees of freedom with light and internal atomic states. We begin by re-visiting the optical Bloch equations, and show how that formalism already includes the basis for inclusion of spatial coordinates in the equations of motion. In particular, we show that the steady state solutions of the optical Bloch equations lead to a nice picture of how atoms excited by an electromagnetic field can feel a friction force. This formalism provides a basis for an exploration of laser cooling, due to the balance of momentum absorbed from light and momentum released in random directions through spontaneous emission. We find that this "spontaneous light force" mechanism is responsible for three important modern laser cooling techniques, optical molasses, beam slowing, and magneto-optical traps. When a very strong light field is applied, the dynamics change, allowing the dipole force of a light beam to manipulate atoms (even single atoms!) through a potential due to the AC Stark shift, as is seen through the dressed atom picture.
