PHIL 110 Lecture Notes - Lecture 48: Total Internal Reflection, Diffraction Grating, Refraction
Document Summary
Refractive index in equation form: n = speed of light in a vacuum. Cause of refraction: bending of light when it passes from one medium to another, caused by change in speed of light. Dispersion: process of separation of light into colors arranged by frequency: red is the longest, blue is shorter, violet is shortest wavelength/highest frequency, components of white light are dispersed in a prism (and in a diffraction grating). Internally reflect 100%, which is the principal reason for use in many optical instruments. Lengthen the light path between lenses, thus eliminating the need for long barrels in binoculars: reflection by prisms re-inverts the image in binoculars. Refraction index larger because the speed of light through glass is slower than in water. Optical fibers or light pipes: thin, flexible rods of special glass or transparent plastic. Light from one end of the fiber is total internally reflected to the other end, resulting in nearly the same brightness of light.
