Induced loss after pulsed and continuous irradiation of single mode and graded index fibres

As part of a measuring program that should give us a survey of the radiation sensitivity of present commercial optical fibres we tested four more single mode (SM) and three graded index (GI) fibres at wavelengths of 850 nm (GI fibres only), 1300 nm and 1550 nm. All fibres were exposed to electron pulses of 500 rd, 3 krd, 10 krd and 100 krd as well as to the continuous gamma radiation of a Co-60 source up to 10 krd and 100 krd. At 10 krd additional measurements with fibre temperatures of +100 degrees C and -50 degrees C were made at both irradiation facilities. After some brief comments on experimental details we present a small fraction of the results and refer to some interesting details we found till now, e.g. the enormous photobleaching in a SM fibre with pure SiO2 core or the reverse temperature dependence of the induced loss after pulsed irradiation of a P containing fibre at very short and longer times after irradiation. Furthermore, induced losses after pulsed and continuous irr adiation are compared, as well as their dependence upon wavelength and temperature. (INT)