Dispersive power of prism and grating in the light of the refined unambiguous angles of incidence, refraction and the unambiguous angle of diffraction

This paper is concerned with the dispersive power of an optical element (viz. a prism and a grating). Making use of the definitions of refined unambiguous angles of incidence, refraction, and the unambiguous angle of diffraction introduced earlier by the author, general unambiguous definition of dispersive power has been offered and that has been subsequently employed to derive unambiguous expressions for the dispersive power of a thin prism and that of a plane diffraction grating. The expressions developed for the dispersive power of a prism and a plane diffraction grating are refined, unambiguous and sophisticated as well. Thus the present contribution will enhance the relevant optical physics literature.