Index of Refraction
The wave incident on an interface can not only reflect, but it can also propagate into the second material.
Claim the speed of an electromagnetic wave is different in matter than it is in vacuum.
- Why??
- Recall, we derived from Maxwell’s eqns in vacuum:
- How are Maxwell’s eqns in matter different?
- e0 ® e , m0 ® m
- Therefore, the speed of light in matter is related to the speed of light in vacuum by:
- The index of refraction is frequency dependent: For example
nblue > nred