The total reflection of a beam of light at the interface of one medium and another medium of lower refractive index, when the angle of incidence to the second medium exceeds a specific critical angle .
If a beam of light passing through a medium A (say glass) strikes the boundary to a medium B of lower refractive index (say air) with a small angle of incidence i, part will be refracted, with an angle of refraction r, and part will be reflected (see illustration a). If i is increased it will reach a critical angle c, at which r = 90° (see illustration b). If i is now increased further, no refraction can occur and all the light energy is reflected by the interface (see illustration c). This total internal reflection occurs when c (given by nsinc = 1) is exceeded (n is the refractive index of A relative to B). The critical angle of optical glass is usually about 40° and total internal reflection is made use of by incorporating prisms in some optical instruments instead of mirrors.
Total internal reflection
- isometric
- isomorphism
- isospin
- isotherm
- isothermal process
- isotone
- isotonic
- isotope
- isotope separation
- isotopic number
- isotopic spin
- isotropic
- IT
- iteration
- j-j coupling
- jet
- JET
- jet propulsion
- Joliot-Curie, Irène
- Joly's steam calorimeter
- Josephson effects
- joule
- Joule heating
- Joule—Thomson effect
- Joule's laws