# Orders of diffraction

1. Mar 15, 2014

Can diffraction be explained for tilted light arrays or only normal incident lights can have diffraction orders?

2. Mar 15, 2014

### Simon Bridge

All light diffracts when it's path is restricted - so you can have diffraction when the light is not normal incidence on the diffraction grating. The reason you are taught the normal-incidence case is that the math is simpler.

You can try it out and see.

3. Mar 15, 2014

### Staff: Mentor

Diffraction from what? What is the light shining onto? What kind of diffraction are we talking about here?

4. Mar 15, 2014

### Simon Bridge

Diffracted from "tilted light arrays" ... English is a second language perhaps? The interpretation is reinforced by the reference to the angle of incidence and a perusal of introductory lessons in diffraction. We would say "diffraction gratings" in the same place.

Still - that is a guess: I could be wrong :)

5. Mar 15, 2014

### Staff: Mentor

This thread was originally in the "Atomic, Solid State, etc." forum, so my first thought was Bragg diffraction of X-rays from a crystal. But that confused me, because with Bragg diffraction you usually do analyze it with the light coming in at an angle!

Another mentor moved it here later.