A gradient-index element is one in which the refractive index varies appreciably in a layer just below the surface of the glass. The present paper deals with practical methods of tracing rays through such a medium. One method, due to L. Montagnino, lends itself to rapid computer ray tracing. A second method, through restricted to the case of spherical symmetry in the index function, lends itself both to computer tracing and to analytical investigations.
© 1970 Optical Society of America
ERICH W. MARCHAND, "Ray Tracing in Gradient-Index Media," J. Opt. Soc. Am. 60, 1-2 (1970)