About geometrical optics
- Geometrical optics, also known as ray optics, is one of the two main branches of optics, the other being physical optics.
- Geometrical optics is based on the assumption that light travels as a straight line and is useful in explaining various optical phenomena, including reflection and refraction, in simple terms.
- Geometrical optics is a useful tool in analyzing the behaviour of optical systems, including the image-forming process and the appearance of aberrations in systems containing lenses and prisms.
- The underlying assumptions of geometrical optics include that light rays:
- Propagate in straight-line paths when they travel in a uniform medium.
- Bend, and in particular, refract, at the interface between two dissimilar media.
- Follow curved paths due to the varying refractive index of the medium.
- May be absorbed as photons and transferred to the atoms or molecules of the absorbing material, causing the absorbing material to heat up or emit radiation of its own.