.  ![\[fig0\] (a) Forward normalized GH shift of the reflected beam versus incident angle for several different values of $W$ when $x_m=0.00000$. (b) Normalized half-width of the reflected beam versus incident angle for the same values of $x_m$ and $W$ as in (a).](fig0){width="0.0cm"}  In figure 0(a), we plot $\delta_r$ as a function of the incident angle for several values of $W$ when $x_d$ is 0.0000 and $x_m$ is 0.00000. We find that the 