  By mapping the scalar Helmholtz equation (SHE) to the Sch\"{r}odinger form we
investigate the behaviour of $\mathcal{PT}$ optical structure when the
refractive index distribution $n$ admits variation in the longitudinal
direction only. Interpreting the Sch\"{r}odinger equation in terms of a
superpotential we determine the supersymmetric partners for $n$. We also obtain
new analytical solutions for the refractive index profiles and provide
graphical illustrations for them.
