Assessment of linear/nonlinear optical constants and dispersion parameters ofSe85−xTe15Sbxglasses for photonic applications

Abstract

The effect of Sbat% on structural and linear/nonlinear optical properties was studied theoretically and experimentally for Se85−xTe15Sbx (x=10,12.5and15at%) glasses. The structural characterization was examined using EDX, XRD, DTA and FTIR. The calculated mean coordination number NCN, average constraints number Ns, overall mean bond energy Eb and average heat of atomization HS increase with Sbat%, which reflects an increase in the system rigidity and correlated to the increase in crosslinking with Sb at%. The linear/nonlinear optical constants such as optical energy gap Eg, Urbach's energy Ee, linear refractive index n, nonlinear refractive index n2, the third order susceptibility χ(3) and the electronic polarizability αp are all evaluated and discussed for the studied films. The dispersion parameters were analyzed using Wemple-DiDomenico model of single oscillator model and the optical/electrical/thermal conductivities and electronic properties were deduced. The optical energy gap Eg, optical conductivities σopt and single oscillator energy Eo decreased while the Urbach's energy Ee and the refractive index n increased with Sbat%. Assessment of linear/nonlinear and other optical and physical parameters shows that Se70Te15Sb15 could be a candidate for several photonic applications.