Optical nonlinearity and supercontinuum generation of tellurite glass at 1.064 μm

Nonlinear optical glasses have aroused great interest due to its compatibility with existing optical fiber systems and excellent infrared transmission. Supercontinuum (SC) is an inherent feature of nonlinear optics, and accurate knowledge of the nonlinear characteristics of glass is important for understanding and optimizing their performance. Two kinds of tellurite glasses with refractive indices of 2.0394 and 2.0211 were synthesized by melt quenching method. The nonlinear absorption and third-order nonlinearity of tellurite glasses were investigated using Z-scan technique with 1.064 mu m picosecond pulses in detail. The values of the respective nonlinear parameters were determined by fitting the experiment data. The nonlinear absorption coefficient, the nonlinear refractive index, and the figure of merit (FOM) are (4.2 +/- 0.4) x 10(-13) m/W, (5.2 +/- 0.6) x 10(-19) m(2)/W, and 11.5, respectively, for the high-refractive-index tellurite glass. A SC spectrum spanning from 0.34 up to 2.6 mu m was obtained by pumping a 30 mm high-refractive-index tellurite glass rod with 170 kW, 1.064 mu m picosecond pulse laser. The tellurite glasses show the great potential as the core and cladding materials of a fiber for generating a broadband mid-IR SC.