Young's double slit experiment is very simple to set up and simple to explain, but it is an example of both diffraction and interference, neither of which are modelled by conventional raytracing.
It is straightforward to render an approximation of the result using textures, but that would require knowing in advance what the result should be. For an arbitrary set up, where the number and arrangement of slits is not known in advance, are there any existing algorithms for modelling the effect in order to generate the correct resulting image?
If not, what would a model need to include in order to accurately produce these effects? Can ray tracing be adapted to use rays carrying additional information, or would an entirely new approach be required?