Double slit experiment / Diffraction of light Does the material of the slits wall influence the diffraction of light? I mean, imagine if the material where the slits were made had electromagnetic properties, wouldn't that influence in some way the diffraction and interference?
Basically, does the electromagnetic properties of the material where light diffracts change its path? I'm sorry if I am not 100% correct, I'm starting to study physics and this experiment absolutely fascinantes me. A 200 year old problem where the current solution is something out of fiction!
 A: I am surprised that there isn't more comprehensive answers to this question from more experienced people. I will try to fill the gap because the topic how material properties influence diffraction pattern is very interesting and is somehow neglected in the physics books. A more complete answer however should be given from someone with rich experimental experience.
The question seems simple but needs deep understanding in several fields.
First, you have to get introduced with the diffraction grating effect - the separation of the colors of the light through diffraction. It acts as a "super prism", separating the different colors of light much more than the dispersion effect in a prism.
Second, it have been known that the magnetic properties of the materials changes the angles by which light is diffracted. This is called Magneto-optic Kerr effect (MOKE) . MOKE is a result from the Faraday effect. It depends if the magnetization vector is parallel or perpendicular to the plane of incidence, light may be diffracted differently in each case because the magnetic field changes the polarization plane.
Third, the temperature of the grating material (the thermal energy of its particles) also matters. It changes the wavelength of the radiated light and doing so will change the colors in the diffraction pattern. For introduction about temperature influence of the radiation you can read about the Black-Body radiation.
So both magnetic and thermal properties influences diffraction. Actually, one of the pioneers in the diffraction optics - Wilhelm Wien, have studied exactly such effects in his PhD thesis called "On the diffraction of light upon photographically miniaturized lattices" but I couldn't find the original text in English.
A: Your question is a very good one and I want to support your thoughts. 
First, there has to be an interaction between the light and the material of the edges. Light is electromagnetic radiation and by this it has an electric and a magnetic field component. These fields are oscillating. So during the transition of the lights units (photons) there is a periodical influence of the photons fields to the surface electrons of the edges material.
Second, the edges we use for diffraction experiments are always thin (Thin in the meaning that the edges are sharp like from a knife or blade). Why this could be important? It is known that for a charged body the discharge of this body happens preferred on spices or other protruding contours. Thin edges further the formation of a common field between the edge and the photons.
Third, diffraction patterns occur not only behind double slits but behind single slits as well as behind every sharp edge. And this experiments one can run with shot one by one photons; after a while the same intensity distribution occurs in the observation screen. All explanations about interference of light from the left and the right edge are obsolet for single shots and more than this behind single edges.
