Example of Confocal Raman Microscopy images. Ge dots on the surface of Si. Left image obtained at characteristic line of Ge (412 cm-1), the right one obtained at main Si line (520 cm-1). Note that dark areas on the right image correspond to bright areas on the left one (arrows), as the Si signal cannot reach from beneath the Ge particles.
Image courtesy of I. Dushkin, NT-MDT.