TY - CONF A1 - Mann, Guido A1 - Krüger, Jörg A2 - Jitsuno, T. A2 - Shao, J. A2 - Rudolph, W. T1 - Nanosecond laser damage of optical multimode fibers T2 - Proceedings of SPIE N2 - For pulse laser materials processing often optical step index and gradient index multimode fibers with core diameters ranging from 100 to 600 μm are used. The design of a high power fiber transmission system must take into account limitations resulting from both surface and volume damage effects. Especially, breakdown at the fiber end faces and self-focusing in the fiber volume critically influence the fiber performance. At least operation charts are desirable to select the appropriate fiber type for given laser parameters. In industry-relevant studies the influence of fiber core diameter and end face preparation on laser-induced (surface) damage thresholds (LIDT) was investigated for frequently used all-silica fiber types (manufacturer LEONI). Experiments on preform material (initial fiber material) and compact specimens (models of the cladding and coating material) accompanied the tests performed in accordance with the relevant LIDT standards ISO 21254-1 and ISO 21254 2 for 1-on-1 and S-on-1 irradiation conditions, respectively. The relation beam diameter vs. LIDT was investigated for fused silica fibers. Additionally, laser-induced (bulk) damage thresholds of fused silica preform material F300 (manufacturer Heraeus) in dependence on external mechanical stress simulating fiber bending were measured. All experiments were performed with 10-ns laser pulses at 1064 and 532 nm wavelength with a Gaussian beam profile. T2 - Pacific Rim Laser Damage 2016 CY - Yokohama, Japan DA - 18.05.2016 KW - laser damage KW - optical fiber KW - nanosecond laser KW - fused silica PY - 2016 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/37140 AN - OPUS4-37140 VL - 9983 SP - 99830T AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany