Refraction index, group & phase velocity of BK7 [Optics & EMW homework]
The table below represents refraction index vs wavelenght for BK7 glass. From it, I'm supposed to find the group velocity and phase velocity for a wavelenght λ=550nm.
| λ (nm) | n | λ (nm) | n | λ (nm) | n |
|---|---|---|---|---|---|
| 404.7 | 1.53023 | 501.7 | 1.52130 | 632.8 | 1.51509 |
| 435.8 | 1.52669 | 532.0 | 1.51947 | 650.0 | 1.51452 |
| 465.8 | 1.52395 | 578.2 | 1.51720 | 676.4 | 1.51372 |
| 480.0 | 1.52283 | 594.1 | 1.51653 | 750.0 | 1.51184 |
How am I supposed to start this problem? I know phase velocity is given by ω/k and that group velocity is given by dω/dk @ k0 or, alternatively, by c/(n(ω0)+ω0(dn/dω @ ω0)). But from there...
Posted Feb 21, 2016, 9:40 PM UTC · edited
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