Thin Film problem

  • Thread starter wsuask
  • Start date
  • #1
wsuask
2
0
A camera lens (n = 1.80) is coated with a thin film of magnesium fluoride (n = 1.45) of thickness 80.0 nm. What wavelength in the visible spectrum is most strongly transmitted through the film?

I have tried to solve this problem for quite a while now, and i hate to admit that there might be a small thing that i am missing. i have reached the following answers : 116 nm, 160 nm and 232 nm and all of them are wrong. I am using this formula: 2t= m*(lambda). I only have 2 tries left so please help me out. Also include a reason why you reached that answer. I have a final comming up and i would love to learn the propper way to do this. Thank you in advance.
 

Answers and Replies

  • #2
pam
458
1
You want destructive interference for reflection at the first surface.
I think this means lambda in the glass=t.
 
  • #3
wsuask
2
0
...

Thanks for your attempt, but I already figured out the correct way of doing it. The index of refraction of the MgF2 is the key to the answer.
 

Suggested for: Thin Film problem

Replies
4
Views
357
  • Last Post
Replies
1
Views
625
Replies
6
Views
1K
  • Last Post
  • Optics
Replies
2
Views
759
  • Last Post
Replies
7
Views
777
Replies
8
Views
1K
Replies
9
Views
1K
Replies
62
Views
2K
Replies
17
Views
600
Top