Transmission of Free-Running Laser Pulses of High Energy and Power Densities Through Previously gamma-Radiated Fiber Waveguides.

摘要

The surface threshold damage levels (STDL's),element of sub 1and rho sub 1 (input energy and power densities),and coupling efficiencies, S, (ratio of output-to-input energy) have been determined for single and multiple optical fiber waveguides of three manufacturers before and after they were exposed to a exp 60Co source. For 400mu s duration ND exp 3+free-running laser pulses the largest STDL of xi sub 1 = 4.66 J/cm exp 2and rho sub 1 = 46,6MW/cm exp 2was observed for multiple laser shots in a Fiberoptic Cable Corp. fiber followed by a single laser shot in a Corning Glass Works fiber with an STDL of element of sub 1 = 4.50 J/cm exp 2and rho sub 1 = 45.0MW/cm exp 2 . The 10exp 6rad(Si) of gamma irradiation to 1cm of fiber did not reduce the low or high xi sub 1 ,rho sub 1or xi values in any of the three types of fibers tested. At lower than STDL,many free-running laser pulses were transmitted through the Corning Glass Works, Fiberoptic Cable Corp. and Valtec Corp. fibers without decreasing xi > 20%. For all fibers in which STDL's were reached there was no evidence that the observed decrease in xi was caused by other than optical damage at the input face of the fibers. (ERA citation 04:047197)