Add to ORKGThis bachelor thesis deals with the problematics of multicore optical fibers and the measuring of their transmission properties. The first part briefly deals with optical fibers in general, then discusses in detail multicore optical fibers, their transmission properties, transmission techniques, splicing and production methods, types of multicore optical fibers, use and measurements performed on specific fibers. The next part deals with the design of a measurement model in the simulation tool VPIphotonics and the simulation of optical fiber measurement. The last part deals with the practical measurement of multicore optical fiber using the method of insertion loss, OTDR method and evaluation of measurement results