Shadowing/absorption effects

[ElliotB256]

At high optical densities, the intensity of cooling light is diminished as it passes through the cold atom sample. This effect can imbalance optical forces, and creates an effective long-ranged interaction between atoms. See e.g. Gaudesius et al for more information.

There are two sources of absorption to consider:

• For sources with ovens, the dominant optical absorption will come from the oven itself, and probably from atoms which are not laser cooled.
• For 3D MOTs of sufficient size, the absorption comes from the laser cooled atoms.

Early thoughts on implementation:

• Something like a grid-based definition of optical intensity for a given beam (which would allow more arbitrary optical fields to be simulated). The grid could be updated according to optical density every N frames, where N is configurable.