A new radiation hard optical fiber for high-dose values

The new Heraeus STU fiber, which is very similar to the radiation resistant Russian KS-4V fiber, was subjected to /sup 60/Co gamma irradiation tests for the first time. The results of spectral measurements (300-850 nm) as well as of measurements at 829 and 1310 nm with different dose rates were compared with those of three "radiation hard" fiber types. The STU fiber shows superior radiation hardness at high-dose values (> 10/sup 4/ Gy), especially at about 1300 nm.