Laser control of atomic and molecular motion by sequences of counterpropagating light pulses

Abstract

The analysis of atomic motion in the field formed by sequences of counterpropagating light pulses reveals the conditions when the field creates the trap in which the temperature of trapped atoms drops to the Doppler limit. The atomic state is described by the wave function using the Monte Carlo wave function method, whereas the atomic motion is considered in the framework of classical mechanics. Laser cooling and trapping is achieved only for non-resonant atom–field interaction. The pulse area does not matter for this effect, in contrast to the repetition period. When the motion of a trapped atom is slowed down, it oscillates around the anti-nodes of a non-stationary standing wave formed by the counterpropagating light pulses at the point where they ‘collide’. The discussed trap is also applicable for trapping and cooling of the molecules for which the matrix of Frank–Condon factors is almost diagonal.

Keywords:

• light pressure force
• counterpropagating pulses
• laser cooling
• trapping
• Monte Carlo wave function method

Notes

This research was supported by the State goal-oriented scientific and engineering program ‘Nanotechnologies and Nanomaterials’ (theme 1.1.4.13/13-H25) and by the State Fund for Fundamental Researches of Ukraine (project F53.2/001).