The Study Of Preparation Technique And Properties On Chalcogenide Glasses For Infrared Fibers

Chalcogenide glasses possess unique far-infrared optical properties,thermal stability and mechanical properties.The third order nonlinear refractive index of chalcogenide glasses is also greate larger than oxide glasses.These glasses have potential applications on ultra-low-loss telecommunication,laser power transmission of mid-far-infrared,image bundles for detector, all-optical switching.Optical properties and preparation technique of Se-based chalcogenide glasses and third order nonlinearity of Ga-based chalcogenide glasses were studied in this thesis.Selenide glasses have low material dispersion,high-energy bandgap,long-wavelength multiphonon edge and it's the perfect candidate for mid-far-infrared fibers.We got the optimal compositions through the experiment,and then obviously reduced the absorption in 8～12μm by improving the technique.A block rod was successed prepared and the tube preparing by rotating technology was also achieved primary success.It is expected to get fibers for 3～12μm.We also prepared 80GeS₂-(20-x)Ga₂S₃-xSb₂S₃ and 80GeS₂-(20-x)Ga₂S₃-xIn₂S₃(x=0,5,10, 15,20) glasses.Their densty,UV-VIS-NIR spectrum,mid-far infrared spectrum and nonlinear refraction and absorption measured by z-scan technique were measured.We discussed the change of galsses' structure,bandgap,multiphonon absorption and n₂ with the content various of Sb or In.Ga-based chalcogenide glasses possess excellent third order nonlinearity and would be good potential candidates for all-optical swiching.This is also the basic research for further studies about Ga-based chalcogenide glasses.