Search results for "Optical disc"
showing 2 items of 2 documents
From local structure to nanosecond recrystallization dynamics in AgInSbTe phase-change materials
2010
Phase-change optical memories are based on the astonishingly rapid nanosecond-scale crystallization of nanosized amorphous 'marks' in a polycrystalline layer. Models of crystallization exist for the commercially used phase-change alloy Ge(2)Sb(2)Te(5) (GST), but not for the equally important class of Sb-Te-based alloys. We have combined X-ray diffraction, extended X-ray absorption fine structure and hard X-ray photoelectron spectroscopy experiments with density functional simulations to determine the crystalline and amorphous structures of Ag(3.5)In(3.8)Sb(75.0)Te(17.7) (AIST) and how they differ from GST. The structure of amorphous (a-) AIST shows a range of atomic ring sizes, whereas a-GS…
Modeling of energy transfer from the photon beam at an optical media
2004
Laser beam could be applied to act in optical media, to build different spatial images. The operation could be made direct by copying an image or through a C.D. The successive points could be realized with relatively high speed, like 103-105 points per second. Each point represents practically a machining operation done by the laser beam. In most cases, energy transfer is made not in a plane, but in a volume, and this requires moving the focal point in positions required by the image we want to create. This is a sequentially operation, made point by point following a definite order, but in the same time, because the image is spatially, we have to adapt also other parameters of the optical s…