In the field of optics, diffusion refers to the scattering of light in the course of reflection or transmission.

  • Most objects exhibit diffuse reflection when light is reflected off their surfaces and scatters in all directions.
  • All objects obey the law of reflection on a microscopic level, but if the irregularities on the surface of an object are larger than the wavelength of light, the light undergoes diffusion.
  • A reflection that is free of the effects of diffusion is called a specular reflection.
  • Diffuse reflection takes place when light reflects off a rough surface. In this case, scattering takes place and waves are reflected randomly in many different directions and so no image is produced.