  A random surface scattering in a one-mode waveguide is studied in the case
when the surface profile has long-range correlations along the waveguide.
Analytical treatment of this problem shows that with a proper choice of the
surface, one can arrange any desired combination of transparent and
non-transparent frequency windows. We suggest a method to find such profiles,
and demonstrate its effectiveness by making use of direct numerical
simulations.

Condensed Matter