Role of Composition and Substrate Temperature on Nonlinear Optical Properties of GeSeTe Thin Films in 0.4–2.4- $\mu \text{m}$ Wavelength Range

The nonlinear optical properties of Ge
₁₀
Se
_90-x
Te
_x
(x = 0,10, 20, 30, 40, 50) thin films have been investigated as a function of composition and substrate deposition temperatures (303, 363, and 423 K). The third-order nonlinear susceptibility and nonlinear refractive index have been estimated. Nonlinearity in refractive index increases with Te content and also with increasing substrate temperature. Among the investigated compositions of Ge
₁₀
Se
_90-x
Te
_x
, the Ge
₁₀
Se
₄₀
Te
₅₀
composition shows more prominent nonlinear refractive index in comparison with pure silica. The high third-order susceptibility and nonlinear refractive index may make these materials capable for high-speed communication fibers.