Abstract
Si 0.75 Ge 0.25 ∕ Si ∕ Si 0.5 Ge 0.5 trilayer asymmetric superlattices were prepared on Si (001) substrate by ultrahigh vacuum chemical vapor deposition at 500 °C. The nonlinear optical response caused by inherent asymmetric interfaces in this structure predicted by theories was verified by in-plane optical anisotropy in (001) plane measured via reflectance difference spectroscopy. The results show Si0.75Ge0.25∕Si∕Si0.5Ge0.5 asymmetric superlattice is optically biaxial and the two optical eigen axes in (001) plane are along the directions [110] and [−110], respectively. Reflectance difference response between the above two eigen axes can be influenced by the width of the trilayers and reaches as large as ∼10−4–10−3 in 15-period 2.7nm-Si0.75Ge0.25∕8nm-Si∕1.3nm-Si0.5Ge0.5 superlattice when the normal incident light wavelength is in the range of 500–1100 nm, which is quite remarkable because the optical anisotropy does not exist in bulk Si.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
