For astronomical applications, different types of step-index all-silica fibers with high-transparency in the whole spectral region from UV (300 nm) to NIR (1100 nm) will be introduced. The light-guiding core-material consists of high-purity silica, especially with low or medium OH-content. In UV region, the losses are mainly influenced by Rayleigh scattering, while the losses in the IR region are limited by traces of OH-groups (in the order of approx. 2 ppm) and fundamental vibration-bands. Due to processing, typical UV-defects below 280 nm can be suppressed significantly within fibers with medium or low OH-content. Especially, one fiber-type with low-OH content in the core possess high resistance against UV radiation in the DUV-region down to 200 nm, which is comparable to high-OH all-silica fibers specially developed for UV-application below 250 nm. In addition, a medium-OH will be presented. The properties of these new fibers in respect to basic attenuation and spectral damage in the UV-region will be discussed, in comparison to high-OH fibers, based on the same measurement-technique. In addition, first results on focal ratio degradation (FRD) and additional loss related to higher propagation angles will be shown, in comparison to standard high-OH fibers.

Date Published: 24 September 2004
PDF: 12 pages
Proc. SPIE 5494, Optical Fabrication, Metrology, and Material Advancements for Telescopes, (24 September 2004); doi: 10.1117/12.568231

Published in SPIE Proceedings Vol. 5494:
Optical Fabrication, Metrology, and Material Advancements for Telescopes
Eli Atad-Ettedgui; Philippe Dierickx, Editor(s)