Enhancement of optical switching parameter and third-order optical nonlinearities in embedded Si nanocrystals: a theoretical assessment
نویسنده
چکیده
Third-order bound-charge electronic nonlinearities of Si nanocrystals (NCs) embedded in a wide band-gap matrix representing silica are theoretically studied using an atomistic pseudopotential approach. Nonlinear refractive index, two-photon absorption and optical switching parameter are examined from small clusters to NCs up to a size of 3 nm. Compared to bulk values, Si NCs show higher third-order optical nonlinearities and much wider two-photon absorption threshold which gives rise to enhancement in the optical switching parameter.
منابع مشابه
Ultrafast and large third-order nonlinear optical properties of CdS nanocrystals in polymeric film.
We report the ultrafast and large third-order nonlinear optical properties of CdS nanocrystals (NCs) embedded in a polymeric film. The CdS NCs of 2 nm radius are synthesized by an ion-exchange method and highly concentrated in the two layers near the surfaces of the polymeric film. The two-photon absorption coefficient and the optical Kerr coefficient are measured with laser pulses of 250 fs du...
متن کاملOptimization of Bistability in Nonlinear Chalcogenide Fiber Bragg Grating for All Optical Switch and Memory Applications
We solve the coupled mode equations governing the chalcogenide nonlinear fiber Bragg gratings (FBGs) numerically, and obtain the bistability characteristics. The characteristics of the chalcogenide nonlinear FBGs such as: switching threshold intensity, bistability interval and on-off switching ratio are studied. The effects of FBG length and its third order nonlinear refractive index on FBG cha...
متن کاملInvestigation of the Third-Order Nonlinear Optical Susceptibilities and Nonlinear Refractive Index In Pbs/Cdse/Cds Spherical Quantum Dot
In this study the third order nonlinear susceptibilities are theoreticallycalculated for an electron confined in an isolated PbS/ CdSe/ CdS spherical core-shellshellquantum dots. Our calculation is associated with intersubband transitions in theconduction band. We used the effective mass approximation in this study which is asimple and straightforward study of the third-order optical nonlineari...
متن کاملThe Third Order Nonlinear Optical behavior of Poly Ether Urethane
Poly (ether) urethane close/open cell (PEUCC/PEUOC) has been prepared by using in situ polymerization approach. The third-order optical nonlinearities of dissolved samples in DMF were characterized by Z-scan technique at the measurement wavelength of 532 nm. The synthesized samples were also examined by optical microscopy and UV-Vis absorption spectroscopy. The nonlinear refractive (NLR) indice...
متن کاملNonlinear Optical Properties of Rigid Polyurethane Foam/SiO2 Nanocomposite
Polyurethane closed cell (PUCC)/SiO2 nanocomposites have been prepared by using in situ polymerization approach. The third-order optical nonlinearities of PUCC/SiO2 nanocomposites, dissolved in DMF are characterized by Z-scan technique at the measurement wavelength of 532 nm. The nonlinear refractive (NLR) indices and nonlinear absorption (NLA) coefficients of samples were calculated from close...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008