FZP material question about xrt

[kklmn]

Hi Bernie,

Yes, this is intended. Material absorption is easy to calculate, and you can test it if you comment those lines 490 and 491 out, but how refractive deflection would interact with grating deflection I just don't know. So presently we use material properties for reflective gratings and consider transmissive gratings (also FZPs) as binary masks where the material is just a stopper. I can imagine this issue could convert into a development project but at least we would need some experimental (measurements) and technical (fabrication of FZPs) basis. From the computational side, I believe we are almost ready for both ray tracing and wave propagation. In rays, we probably need to apply the grating equation twice: at the front and at the back surface. In waves, we can calculate the phase advance in the body by rays and then apply the Kirchhoff diffraction from the back surface.

Konstantin

[bjkoz]

Thanks for the clarification.

I agree, the wave case should work as you describe, see for example:
https://doi.org/10.1364/OE.25.001831

I'll keep this in mind if I happen to come across experimental measurements in the literature.
Bernie