There are basically two types of multi-mode fibers: graded-index fibers and step-index fibers. In step-index fibers, the refractive index decreases dramatically between the core and the cladding. They are available as quartz/quartz fibers or as so-called HCS fibers (with a quartz core and a plastic cladding). In graded-index fibers, however, the refractive index decreases steadily with increasing radial distance from the fiber axis.
Fibers for harsh environments
These fibers were developed for use in harsh environmental conditions. High temperatures and increased pressure occur in particular in geophysical applications such as drilling deep holes.
These fibers can be used at temperatures of up to +300°C. In addition, they have a high chemical resistance.
Gradient index fibers are available on request.