  Recent researches show that the fluctuations of the dielectric mirrors
coating thickness can introduce a substantial part of the future laser
gravitational-wave antennae total noise budget. These fluctuations are
especially large in the high-reflectivity end mirrors of the Fabry-Perot
cavities which are being used in the laser gravitational-wave antennae.
  We show here that the influence of these fluctuations can be substantially
decreased by using additional short Fabry-Perot cavities, tuned in
anti-resonance instead of the end mirrors.
