  Raman and Photoluminescence (PL) experiments on correlated metallic
La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ have been carried out using different excitation
wavelengths as a function of temperature from 15 K to 300 K. Our data suggest a
Raman mode centered at 1800 cm$^{-1}$ and a PL band at 2.2 eV. The intensities
of the two peaks decrease with increasing temperature. The Raman mode can be
attributed to a plasmon excitation whose frequency and linewidths are
consistent with the measured resistivities. The PL involves intersite
electronic transitions of the manganese ions.

Condensed Matter