Fermat’s Principle and General Considerations Regarding Centered Optical Systems

Abstract

Faraday and Lentz discovered that a varying magnetic field produces an electric field. Subsequently, Maxwell hypothesized that the inverse process was possible—that a varying electric field will produce a magnetic field—and he postulated a set of equations relating to electromagnetism in his famous Treatise on Electricity and Magnetism. Ever since then, electric and magnetic phenomena have been regarded as two interconnected aspects of the electromagnetic field, which, in turn, is propagated by electromagnetic waves. Moreover, Maxwell showed that light waves are a particular type of electromagnetic wave, so the field of optics merged with electromagnetism. This suggests that one could study the propagation of light waves across an optical system using Maxwell´s equations along with suitable boundary conditions, depending on the nature of the media involved.