Pulsed X-ray induced attenuation measurements of single made optical fibers and coupler materials

Pulsed X-ray induced transient radiation attenuation measurements of single mode optical fibers have been performed versus total dose, light wavelength, optical power and fiber coil diameter in order to determine the behaviour of parameters sensitive to ionizing radiation. The results did not show any photobleaching phenomenon and the attenuation was found independent of the spool diameter. As expected, transient attenuation was lower for higher wavelengths. The recovery took place in the millisecond range and was independent of total dose, light wavelength and optical power. In optical modules and devices a large range of behaviours was observed according to coupler material i.e. the Corning coupler showed a small peak attenuation that remained more than one day later; on the other hand LiTaO₃ material experienced an order of magnitude higher peak attenuation and a recovery in the millisecond range. For applications with optical fibers and integrated optics devices we showed that in many cases the optical fiber (length above 100 m) is the most sensitive device in a transient ionizing radiation field