Refractive Index
Refractive Index
The refractive index measures how much a medium slows light, which sets how strongly it bends rays.
The index is n = c/v. where c is the speed of light in vacuum and v its speed in the medium.
Inputs
c := 3e8 m/s=3e+08 m/s
v := 2e8 m/s=2e+08 m/s
Divide vacuum speed by speed in the medium.
n := c/v=1.5
Results
A value of 1.5 (typical glass) means light travels at two-thirds its vacuum speed inside. Higher index means stronger bending and slower light.
Assumptions & limitations
- Non-absorbing medium.
- Single wavelength.
- Light speeds in the same units.