  It is shown that coupling system between fractal membranes and a Gaussian
beam passing through a static magnetic field has strong selection capability
for the stochastic relic gravitational wave background. The relic GW components
propagating along the positive direction of the symmetrical axis of the
Gaussian beam might generate an optimal electromagnetic perturbation while the
perturbation produced by the relic GW components propagating along the negative
and perpendicular directions to the symmetrical axis will be much less than the
former.The influence of the random fluctuation of the relic GWs to such effect
can be neglected and the influence of the random fluctuation of the relic GWs
to such effect can be neglected.
