Development of high numerical aperture fiber bundles (FBs) requires use of thermally matched pair of glasses with a high difference of refractive indices. We have developed a pair of glasses with high refractive index contrast Δn_D>0.2, suitable for fabrication of optical fiber bundles with numerical aperture NA > 0.85. Core glass was synthetized in the lanthanum oxide system Nb₂O₅-Ta₂O₅-SiO₂-ZrO₂-B₂O₃-Al₂O₃-La₂O₃-BaO-SrO. Borosilicate glass synthetized in oxide system SiO₂-Al₂O₃-B₂O₃-MgO-CaO-Na₂O-K₂O, thermally matched to the core glass, is used for the fiber cladding. The glasses also have high transmission from 350 to over 600 nm, which makes them ideal for fluorescence imaging applications. These thermally stable, crystallization-free lanthanum and borosilicate glasses have been successfully applied to development of proof-of-concept large diameter optical fiber.

中文翻译：

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高对比度无铅软镜，用于大数值孔径成像束

高数值孔径纤维束（FBs）的开发需要使用折射率差异较大的热匹配眼镜。我们已经开发了一副眼镜具有高折射率对比的Δn _d > 0.2，适合于与数值孔径NA> 0.85的光纤束的制造。在氧化镧体系Nb ₂ O ₅ -Ta ₂ O ₅ -SiO ₂ -ZrO ₂ -B ₂ O ₃ -Al ₂ O ₃ -La ₂ O ₃ -BaO-SrO中合成芯玻璃。氧化物体系SiO ₂ -Al中合成的硼硅酸盐玻璃与芯玻璃热匹配的₂ O ₃ -B ₂ O ₃ -MgO-CaO-Na ₂ O-K ₂ O用于光纤包层。该眼镜还具有从350到600 nm以上的高透射率，这使其非常适合荧光成像应用。这些热稳定，无结晶的镧和硼硅酸盐玻璃已成功地用于开发概念验证的大直径光纤。