A collimated beam of laser light of wavelength 514 nm is normally incident on a smooth glass slab placed in air. Given the refractive indices of glass and air are 1.47 and 1.0, respectively, the percentage of light intensity reflected back is
Reflectance =[(n1-n2) /(n1+n2)] ^2 is derived from electromagnetic theory. It is a long derivation and needs knowledge of Electrodynamics. If you are interested in knowing the con...