Optical path
 |
The path that light takes in traversing an optical system is often called the optical path. The physical length of an optical device can be reduced to less than the length of the optical path by using folded optics. The optical path length as defined in optics is the length of the path multiplied by the index of refraction of the medium.
See also
 | This optics-related article is a stub. You can help Wikipedia by expanding it. |