• Support PF! Buy your school textbooks, materials and every day products Here!

Diffracting grating problem

  • #1
15
0

Homework Statement


A diffraction grating has period D, and each element of the grating consists of a pair of narrow slits separated by D/N where N is an integer.
a) Sketch the diffraction pattern when the grating is normally illuminated
b)Calculate the relative intensities $I_n$ of the various diffraction peaks of order n, for the case N=4. Which peaks are forbidden?
c)For the case N=2 show that the solution reduced to that of a simple grating of period D/2.

Homework Equations



See step 3 for my full attempt to solve the problem.

The Attempt at a Solution



I am aware that the above solution is incorrect, because I ended up ignoring so many things that the solution equals to the one for a double slit, but superposed on a comb of delta functions. My problem is that I don't know how to write the complete function of the grating as a simple function which one could nicely manipulate. Could someone please point me in the correct direction?

P.s I am aware that my attempt of the solution is not the most clear.

P.s.s Link to the higher resolution picture here.
 

Attachments

Answers and Replies

  • #2
34,053
9,913
"narrow slits" -> you can ignore single-slit effects. There is no envelope.

The pattern there is for the grating. You can see which phase you get between the two slits for those peaks.
What are g and a?
 

Related Threads on Diffracting grating problem

  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
7
Views
4K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
1K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
0
Views
2K
  • Last Post
Replies
2
Views
4K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
1
Views
454
Top