The　optical,　dielectric,　and　structural　characteristics　of　Si15Sb85　phase　change　memory　thin　films　under　a　moving　continuous-wave　laser　initialization　are　studied　by　using　spectroscopic　ellipsometry　and　high-resolution　transmission　electron　microscopy.　The　dependence　of　complex　refractive　index,　dielectric　functions,　absorption　coefficient,　and　optical　band　gap　of　the　films　on　its　crystallization　extents　formed　by　the　different　initialization　laser　power　are　analyzed　in　detail.　The　structural　change　from　as-deposited　amorphous　phase　to　distorted　rhombohedra-Sb-like　crystalline　structure　with　the　increase　of　initialization　laser　power　is　clearly　observed　with　sub-nanometer　resolution.　The　optical　and　dielectric　constants,　the　relationship　between　them,　and　the　local　atomic　arrangements　of　this　new　phase　change　material　can　help　explain　the　phase　change　mechanism　and　design　the　practical　phase　change　memory　devices.　(C)　2011　Elsevier　B.V.　All　rights　reserved.