Optical fibers for 355nm pulsed lasers and high-power broadband light sources

In the past, the spectral stability of multimode UV-fibers has been mainly characterized using deuterium lamps with a broadband spectrum in the DUV. In meantime, new UV light-sources with higher powers are available. For example, improved pulsed Nd:YAG lasers with higher harmonics or high-power broadband plasma lamps are interesting candidates for new systems and applications. Because of better beam quality, multimode all-silica fibers with core diameter smaller than 100 μm can be recommended. A new step-index fiber with a large cladding-to-core ratio will be introduced. Using the new light-sources, the degradation during UV-light delivery will be described in detail, comparing the hydrogen-loaded and non-loaded version of this fiber. These results of UV-induced damage will be compared to a commercially available improved 100 μm UV-fiber damaged with deuterium lamp.