Lawrence Berkeley National Laboratory

In several cases, coupling synchrotron light into optical fibers can substantially facilitate the use of beam diagnostic instrumentation, that measures longitudinal beam properties by detecting synchrotron radiation. It has been discussed in [1] with some detail, how fiberoptics can bring the light at relatively large distances from the accelerator, where a variety of devices can be used to measure beam properties and parameters. Light carried on a fiber can be easily switched between instruments so that each one of them has 100 percent of the photons available, rather than just a fraction , when simultaneous measurements are not indispensable. From a more general point of view, once synchrotron light is coupled into the fiber, the vast array of techniques and optoelectronic devices, developed by the telecommunication industry becomes available.In this paper we present the results of our experiments at the Advanced Light Source, where we tried to assess the challenges and limitations of the coupling process and determine what level of efficiency one can typically expect to achieve.