The problem of ray tracing in inhomogeneous media has been examined in an attempt to find an accurate yet computationally efficient method. Several numerical techniques have been compared. It is shown that Montagnino’s Taylor-series-expansion method [J. Opt. Soc. Am. 58, 1667 (1968)] is superior to Euler’s method, which is a standard numerical method for solving the differential equation. It is also shown that, by a transformation of the independent coordinate from the physical path length to the optical path length, more-accurate optical path calculations may be obtained.
© 1982 Optical Society of America
W. H. Southwell, "Ray tracing in gradient-index media," J. Opt. Soc. Am. 72, 908-911 (1982)