  It is shown that the well-known blue-shift of the fundamental absorption edge
in as-deposited compositionally modulated amorphous Si/Ge and As6Se94/Se80Te20
multilayers (with periods of 4-8 nm) is further enhanced due to the thermal or
laser-induced intermixing of adjacent layers. The laser-induced intermixing
process, as supported by experiments and model calculations, can be attributed
to both the local heating and photo-effects in As6Se94/Se80Te20 multilayers,
while only the thermal effects were observed for Si/Ge multilayers. Structural
transformations, based on this enhanced interdiffusion, provides good
capability for spatially patterning optoelectronic devices and digital
information recording.
