What are Solid core or multicore?
It will depend on the use to that the optic is put and the actual installation conditions. Solid core optics has usually, a larger bending radius to ignore important losses. Moreover, because of the transparent amount of the core, unless the contrast with the background is sufficient the appearance is inferior luminance.
Multicore optics, conversely, has a more flexible construction, particularly in large diameters. Due to the reduced transparency of the optic, the luminance shows greater.
Solid core fibers can operate in several types with higher screen temperatures and they can be attached (at least in theory) to generators which are more powerful without damage to the core. This must be said, however, as the long-term effects, particularly those related to the power density of the systems, are as even undetermined.