Phase changes between amorphous and crystallized states were induced by laser irradiation with nanosecond pulses in GexTey films grown by metal organic chemical vapor deposition. The different phases were obtained by adjusting the pulse energy and could be distinguished by their different optical reflectivities. The corresponding structural changes were studied by Raman spectroscopy, showing marked differences for the two phases. A clear correlation is found between optical reflectivity levels, crystallographic state and the evolution of Ge–Ge, Te–Te, and Ge–Te Raman bands.