Optical path

The path that light takes in traversing an optical medium or 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.

Factors affecting optical path

Path of light in medium, or between two media is affected by the following:

• Reflection
• Refraction
• Dispersion of light
• Total Internal Reflection
• Absorption

Simple materials used

• Lenses
• Prisms
• Mirrors
• Transparent materials (e.g. optical filters)
• Translucent materials (e.g. frosted glass)
• Opaque materials

See also

• Optical path length
• Axiom optics

‘change in optical length is equal to wavelength of light passed’