Four-Color Stimulated Optical Forces for Atomic and Molecular Slowing

Abstract

Stimulated optical forces offer a simple and efficient method for providing optical forces far in excess of the saturated radiative force. The bichromatic force, using a counterpropagating pair of two-color beams, has so far been the most effective of these stimulated forces for deflecting and slowing atomic beams. We have numerically studied the evolution of a two-level system under several different bichromatic and polychromatic light fields, while retaining the overall geometry of the bichromatic force. New insights are gained by studying the time-dependent trajectory of the Bloch vector, including a better understanding of the remarkable robustness of bi- and polychromatic forces with imbalanced beam intensities. We show that a four-color polychromatic force exhibits great promise. By adding new frequency components at the third harmonic of the original bichromatic detuning, the force is increased by nearly 50% and its velocity range is extended by a factor of three, while the required laser power is increased by only 33%. The excited-state fraction, crucial to possible application to molecules, is reduced from 41% to 24%. We also discuss some important differences between polychromatic forces and pulse trains from a high-repetition-rate laser.

9 pages, 11 figures. Modified, especially on p.3, to more clearly specify the laser field configuration and parameter definitions

References in corpus (1)

• Bichromatic Slowing of Metastable Helium

Cited by in corpus (11)

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• Simulations of the bichromatic force in multilevel systems
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• Large molasses-like cooling forces for molecules using polychromatic optical fields: A theoretical description
• Optical stimulated slowing of polar heavy-atom molecules with a constant beat phase
• Radiation Pressure on a Two-Level Atom: an Exact Analytical Approach
• Instrumentation for laser physics and spectroscopy using 32-bit microcontrollers with an Android tablet interface
• Stimulated Slowing of Yb Atoms on the Narrow ${}^1{S}_0{\to }^3{P}_1$ Transition