Question

What are the laws of optics?

Answer 1

1. Laws of reflection:
   
   1.1 The principle when the light rays fall on a smooth surface, the angle of reflection is equal to the angle of incidence.
   1.2 The incident ray, the reflected ray, and the normal to the surface all lie in the same plane.
2. Laws of refraction:
   
   2.1 The incident ray, refracted ray, and the normal to the interface of two media at the point of incidence all lie on the same plane.
   2.2 The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant. This is also known as Snell’s law of refraction.
   $\frac{\sin \mathrm{i}}{\sin \mathrm{r}}=\mathrm{constant}$
3. Brewster's law:
   
   When an unpolarized light of known wavelength is incident on a transparent substance surface, it experiences maximum plane polarization at the angle of incidence whose tangent is the refractive index of the substance for the wavelength.
   $$\begin{gathered} \mathrm{refractive}\mathrm{index}\mathrm{of}\mathrm{the}\mathrm{medium}=\mathrm{tangent}\mathrm{of}\mathrm{the}\mathrm{incident}\mathrm{angle} \\ \mathrm{\mu }=\tan \mathrm{i} \end{gathered}$$