The use of optical time domain reflectometers to measure radiation-induced losses in optical fibers

Fiber-optics exposed to ionising radiation suffer from induced transmission loss from which recovery can take place over periods up to years after exposure. Measurement of this behavior presents difficulties over the longer times, but is nessessary to permit predictions of fiber behavior in applications where long-term exposure to ionising radiation is involved, as in reactor environments, medical applications, space or accelerator instrumentation. This paper presents a summary of a study by a number of laboratories of the NATO Panel IV, Research Study Group 12 Nuclear Effects Task Group into the suitability of the use of optical time domain reflectometry for these measurements. Results are shown which validate this approach when used according to recommended guidelines.