- #1
stunner5000pt
- 1,461
- 2
given is a graph of n(lambda) vs lambda where n is the index of refraction
N(1000) =1.45
Estimate Vphase and group velocity using the above info.
i know that [tex] n = \frac{c}{v_{\phi}} = \frac{ck}{\omega} [/tex]
i can't simply susbtitute into that above relation because the lambda given is that lambda in the vacuum and thus the lambda would be different in the medium. Also oncei found v phase how would i go about finding group velcoity, since group velocity is a derivative, do i simply pick off two points on the graph and find the slope?
But first i need to figure out phase velocity which i can't get and i don't know if its right
Please help!
N(1000) =1.45
Estimate Vphase and group velocity using the above info.
i know that [tex] n = \frac{c}{v_{\phi}} = \frac{ck}{\omega} [/tex]
i can't simply susbtitute into that above relation because the lambda given is that lambda in the vacuum and thus the lambda would be different in the medium. Also oncei found v phase how would i go about finding group velcoity, since group velocity is a derivative, do i simply pick off two points on the graph and find the slope?
But first i need to figure out phase velocity which i can't get and i don't know if its right
Please help!