(( QUARTZ GLASS, ESPECIALLY FLUORINE-DOPED QUARTZ GLASS; SEMI-FINISHED QUARTZ GLASS AND FLUORINE-DOPED QUARTZ GLASS PRODUCTS, SUCH AS TUBES, RODS, PLATES OR BLOCKS, FOR LABORATORY, OPTICAL AND INDUSTRIAL USE; FIBERS FOR OPTICAL WAVE-GUIDES; )) PERFORMS FOR THE FIBER PRODUCTION FOR OPTICAL WAVE GUIDES