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We report on photoluminescence (PL) properties of Er3+ doped Ga10Ge25S65 glass. Experiments were performed using 5 ns laser pulses at 980 nm (532 nm), in resonance with the 4I15/2→4I11/2 (4I15/2→2H11/2) transition of the Er3+ ions. PL bands were observed from the blue to the near-infrared and the dependence of their intensity as a function of the laser intensity was analyzed. The PL temporal behavior was analyzed through rate equations for the population densities and using the Inokuti-Hirayama model. The results allowed identification of the PL pathways and the characterization of energy transfer processes involving pairs of ions. [ABSTRACT FROM AUTHOR]

Optical properties of a neodymium (Nd3+) doped glass having composition based on the (Ga2S3)–(GeS2) system are reported. Transition probabilities, radiative lifetimes, and branching ratios related to Nd3+ levels were determined. Frequency upconversion (UC) luminescence due to nonresonant excitation at 1064 nm was observed at ≈535, ≈600, and ≈670 nm. The dependence of the UC intensity on the laser intensity and on the Nd3+ concentration as well as the dynamics of the luminescence process were studied. The results indicate that two-photon absorption by isolated Nd3+ ions and energy transfer among pairs of Nd3+ ions contribute to the UC luminescence. [ABSTRACT FROM AUTHOR]

We report on orange-to-blue frequency upconversion (UC) in Pr3+ doped chalcogenide glass (Ga10Ge25S65) doped with Ag2S and heat treated under different conditions to nucleate silver nanoparticles (NPs). The experiments were performed using 7 ns pulses from a dye laser that operates at ∼590 nm, in resonance with the 3H4→1D2 transition of Pr3+ ions. The enhancement observed in the UC emission at ∼494 nm, ascribed as 3P0→3H4 transition of the Pr3+ ion, is attributed to the large local field acting on the emitting ions due to the presence of the metallic NPs. [ABSTRACT FROM AUTHOR]

Nonlinear (NL) optical properties of antimony–germanium–sulfur (Sb–Ge–S) glasses were investigated using laser pulses of 65 fs at 1560 nm. Samples having concentration ratio [S]/[Ge]=2.69 with different antimony concentrations were studied. Glasses with different oxidation states of Sb were investigated using the thermally managed Z -scan technique. The influence of the Sb oxidation state on the NL properties was evaluated. NL refraction indices of electronic origin, n2≈10−13 cm2/W, two-orders of magnitude larger than for fused silica and NL absorption coefficients smaller than 0.55 cm/GW were measured. Appropriate figures-of-merit for photonic applications were determined. [ABSTRACT FROM AUTHOR]