Influence of core diameter and coating material on nanosecond laser-induced damage threshold of optical multimode fibers

摘要

Single and multi pulse laser-induced damage thresholds (LIDT) of core, cladding, and coating materials of high-power optical multimode fibers were determined in accordance with ISO 11254 for 532 nm and 1064 nm wavelength in the 10-ns pulse duration regime with spatial Gaussian beam shape. For all-silica fibers, LIDT increases with rising core diameter in a range between 100-600 pm for a constant cladding-core ratio of 1.2. The damage resistance of the low refracting cladding (0.3 % fluorine doped fused silica) is comparable to the undoped Si02 core. Coating materials show significantly lower LIDT than light-guiding parts, of the fibers.