ABSTRACT
A refractive element transmits electromagnetic radiation and in general the maximization of the transmission is desired by the designer. The true nature of light is probably impossible to know. However, Maxwell’s theory and the quantum theory provide a consistent theoretical explanation of all optical phenomena. Maxwell assumed that light is merely one form of electromagnetic energy that has a wave form and a periodic nature. The electromagnetic spectrum is partitioned into various classes of electromagnetic waves, based on ranges of wavelength. The quantum theory employs Newton’s idea that light is composed of small discrete bodies, called photons. Modern theory accepts the dual nature of light, i.e., that light exhibits both the wave character of Maxwell’s formulations and the particle character envisaged by Newton. The optical properties of the material are functions of the wavelength of the incoming light, temperature of and applied pressure on the material, as well as the environment acting on the material.
