I am trying to simulate a simple setup where I have a point source of broadband light whose light is incident upon a spherical crystal at a central angle $\theta_i$. Assuming Bragg diffraction some of this light will be diffracted as if it was specularly reflected off a mirror - here is a small example of an output of my simulation that I would be expecting for example:
Here I have light emanating from a point source impinging upon a spherical mirror crystal. Each ray is generated at the point source, propagated towards the spherical mirror and specularly reflected. It is then assigned a wavelength (colour in the image) based on the Bragg condition for the angle at which the ray impinges and first order m=1 (all higher will be neglected, the reason doesn't matter).
My question is this: Currently, I am calculating the diffraction wavelength for each ray as if the crystal has the same spacing along each direction of its 2D surface. i.e. whatever the impinging angle I always use the same interatomic spacing for the crystal in the Bragg condition. What if the crystal has rectangular lattice? How can I treat this problem better?
