At Singapore Opl

ENGINEERING OPTICS WITH MAT LAB*

the light ray would follow that path for which the OPL between the two points is an extremum, i.e., 8{OPL) = 6 I n(x,y,z)ds = 0 (1.1-2) Jc in which S represents a small variation. In other words, a ray of light will travel along a medium in such a way that the total OPL assumes an extremum. As an extremum means that the rate of change is zero, Eq.