In this figure, example (a) and example (b) appear side-by-side, with (a) on the left and (b) on the right. Both appear as simple graphs.

In example (a), the x-axis is labeled (lambda)in and the y-axis is labeled (lambda)out. The right-most point of the x-axis is labeled "R/2" and the top-most point of the y-axis is also labeled "R/2." A blue line begins at the intersection of the x- and y-axes and extends upwards to the right at a 45-degree angle. When it reaches R/2 on the x-axis and R/2 on the y-axis, it levels off and extends horizontally just beyond R/2 on the x-axis. A dotted line extends from R/2 on the x-axis to the point on the blue line where it levels off and reaches equilibrium.