PM Fibers without Photodarkening
In germanium-doped fibers, the optical attenuation of the fiber increases under ultraviolet, violet, blue, and green wavelengths. This so-called photodarkening can be prevented by using pure silica fiber cores.
PM fibers with quartz glass cores are used, for example, in environmental monitoring and biomedical applications such as flow cytometry, DNA sequencing, and confocal microscopy. These fibers are compatible with coreless end caps (MM125) which expand the output beam. This prevents excessive power density at the end of the fiber.
