Metadata
shorthands: {}
aliases: [Optical distance, OPL]
created: 2021-10-24 23:30:14
modified: 2022-01-10 04:13:04
The optical path length or OPL is the product of the length of the optical path taken by light and the refractive index of the medium through which a light ray propagates. It is proportional to the time it takes for the light to traverse the given path, so this value can be used when utilizing Fermat's principle.
For homogeneous media:
Where
When the refractive index varies along the path, it is given by a line integral:
Where