Refinement of the definitions of angles of incidence, reflection, refraction, and critical angle in ray optics

Abstract

This paper considers the definitions of angles of incidence, reflection, refraction as well as critical angle in the long-running literature of ray optics. The traditional definition of each of those angles has been found to be ambiguous on account of the fact that it is not at all in compliance with the fundamental definition of angle in geometry. With a view to getting rid of such ambiguity and bringing sophistication in the relevant field of study, an attempt has been made to refine the definition of each of the aforesaid four angles appearing in geometrical optics. Based on the refined definitions of angle of incidence and angle of refraction, the novel unambiguous concept of critical angle has been finally offered using simultaneously the generalized vectorial law of refraction developed by the author in 2005.