Simulations of the bichromatic force in multilevel systems

Abstract

Coherent optical bichromatic forces have been shown to be effective tools for rapidly slowing and cooling simple atomic systems. While previous estimates suggest that these forces may also be effective for rapidly decelerating molecules or complex atoms, a quantitative treatment for multilevel systems has been lacking. We describe detailed numerical modeling of bichromatic forces by direct numerical solution for the time-dependent density matrix in the rotating-wave approximation. We describe both the general phenomenology of an arbitrary few-level system and the specific requirements for slowing and cooling on a many-level transition in calcium monofluoride (CaF), one of the molecules of greatest current experimental interest. We show that it should be possible to decelerate a cryogenic buffer-gas-cooled beam of CaF nearly to rest without a repumping laser and within a longitudinal distance of about 1 cm. We also compare a full 16-level simulation for the CaF B$\leftrightarrow$X system with a simplified numerical model and with a semiquantitative estimate based on 2-level systems. The simplified model performs nearly as well as the complete version, whereas the 2-level model is useful for making order-of-magnitude estimates, but nothing more.

References in corpus (7)

• Magneto-optical trapping of a diatomic molecule
• Laser cooling and slowing of CaF molecules
• Rotational state microwave mixing for laser cooling of complex diatomic molecules
• Lifetime of the A(v'=0) state and Franck-Condon factor of the A-X(0-0) transition of CaF measured by the saturation of laser-induced fluorescence
• Four-Color Stimulated Optical Forces for Atomic and Molecular Slowing
• Bichromatic Slowing of Metastable Helium
• Comparison of Electromagnetically Induced Transparency in lambda, cascade and vee three-level systems

Cited by in corpus (13)

• Precision Measurement of Time-Reversal Symmetry Violation with Laser-Cooled Polyatomic Molecules
• Coherent Bichromatic Force Deflection of Molecules
• Radiation Pressure Force from Optical Cycling on a Polyatomic Molecule
• A laser cooling scheme for precision measurements using barium monofluoride (137Ba19F) molecules
• Deflection of a Molecular Beam Using the Bichromatic Stimulated Force
• Bright, continuous beams of cold free radicals
• Large molasses-like cooling forces for molecules using polychromatic optical fields: A theoretical description
• Multivalent optical cycling centers in polyatomic molecules
• Optical stimulated slowing of polar heavy-atom molecules with a constant beat phase
• Deflection of barium monofluoride molecules using the bichromatic force: A density-matrix simulation
• Frequency-doubled Nd:YAG MOPA laser system with programmable rectangular pulses up to 200 microseconds
• Stimulated Slowing of Yb Atoms on the Narrow ${}^1{S}_0{\to }^3{P}_1$ Transition
• Quantum theory of statistical radiation pressure in free space