Glass formation and third-order optical nonlinear properties within TeO2–Bi2O3–BaO pseudo-ternary system

Tellurite glasses from TeO2–Bi2O3–BaO pseudo-ternary system were prepared using a conventional melt-quenching method and its glass-forming region was determined. A series of glasses were selected and their third-order optical nonlinearities (TONL) were measured by employing the Z-scan method at a wavelength of 800 nm with femtosecond laser pulses. The results showed that glass former Te4+ ions exhibited positive influences on the TONL and glass modifiers Ba2+ ions behaved similarly; low concentrated Bi3+ ions as glass modifiers weakened the nonlinearities, but an excess amount of Bi3+ behaved oppositely. FTIR measurements demonstrated that chemical bonds especially Te–Oeq vibrated at a high energy level remarkably promoted the TONL susceptibility χ(3), and the glass sample with the highest Bi2O3 content exhibited the largest χ(3) value which was due to the presence of BiO3 polyhedra.

Research Highlights
► Determination of glass forming range in TeO2–Bi2O3–BaO pseudo-system.
► Investigation of third-order optical nonlinearities of TeO2–Bi2O3–BaO glasses.
► Chemical bonds with high vibrating energy leaded to high optical nonlinearities.
► Observation of strong two-photon absorption in 75TeO2–20Bi2O3–5BaO (in mol%) glass.