  We report far-infrared reflectance measurements on polycrystalline
superconducting samples of SmO$_{1-x}$F$_{x}$FeAs ($x$ = 0.12, 0.15 and 0.2).
We clearly observe superconductivity induced changes of reflectivity in a broad
range of energies, which resembles earlier optical measurements on high $T_{c}$
cuprates. The superconducting-to-normal reflectivity ratio $R_{s}/R_{n}$ grows
for the photon energies below 18 meV and shows a complicated structure due to
the presence of a strong infrared-active phonon at about 10 meV.
