Delivery of Nd-YAG laser pulses by large optical fiber: dependence of the laser intensity profile on threshold of energy transmission

摘要

A laser-induced damage study on large-core, multimode fiber is presented. We develop a numerical analysis concerning high laser power transmission based on a beam ray tracing. Data are compared with experimental results obtained with a Nd-YAG laser (1064 nm-15 ns) and a step-index fiber. Studies of bulk damage in fiber show that the incident laser beam profile and the launching conditions are responsible of high-intensity sites inside the fiber. Gaussian and multimode spatial profiles are numerically investigated. Finally, we discuss optima laser characteristics to increase the energy transmission in the fiber