Optical and structure properties of amorphous Ge–Sb–Se films for ultrafast all-optical signal processing

摘要: Abstract In this paper, we deposited amorphous chalcogenide Ge–Sb–Se films using the RF sputtering method, then measured their optical and structural properties various diagnosis tools. The linear refractive index band-gap for as-deposited were analyzed as a function of chemical composition mean coordination number (MCN). third-order nonlinearities predicted by applying Z-scan method combined with model developed Sheik-Bahae. relationship between film compositions was Raman spectra in terms evolution. data suggests that “defect” gap states network play an important role nonlinearity these films. Ge 20 Sb 15 Se 65 most suitable all-optical signal processing applications had large nonlinear indices (−8.735 × 10 −15  m 2 /W), moderate absorption (8.592 × 10 −9 m/W) showed ultrafast response time (66 fs).