Group velocity dispersion

  • Thread starter Dimani4
  • Start date
  • #1
50
0

Main Question or Discussion Point

Hey ppl,
I have a question for you.

For the case of light propagation in the air the the group-velocity dispersion parameter D is infinity because the derivative of the group velocity should be a zero (group velocity is constant ; w=ck and Vgroup=dw/dk). Who can explain me this? dispersion parameter is infinity meaning that the pulse will spread very fast. I never thought about that question but maybe I'm wrong. Plz clarify me that point.

formula for D parameter you can find here:
http://en.wikipedia.org/wiki/Dispersion_(optics)
 

Answers and Replies

  • #2
50
0
the question is solved. you can't not turn upside down the second derivative. i.e

a=(Dispersion parameter)=(approx) d2(k)/d2(w)[tex]\neq[/tex]1/d2(w)/d2(k). here was the problem. in the case of light propagation through the air a should equal to zero.


d2()-second derivative=[tex]\partial[/tex]2

d2(k)/d2(w)=[tex]\partial[/tex]2k/[tex]\partial[/tex]2w
 
Last edited:

Related Threads on Group velocity dispersion

Replies
2
Views
3K
Replies
5
Views
4K
  • Last Post
2
Replies
37
Views
7K
Replies
1
Views
4K
  • Last Post
Replies
2
Views
752
Replies
3
Views
670
Replies
1
Views
6K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
2K
Top