Coupling characteristics of multicore photonic crystal fiber doped with germanium

A new design of a multicore doped photonic crystal fiber (PCF) is proposed and analyzed through the vectorial beam propagation method (VBPM). The fiber is made up from silica doped with germanium and has two identical cores horizontally equidistant from the main core. The signal power launched in the central core is equally divided between the two neighboring cores with 50% of the coupling ratio. Through numerical simulations, it is demonstrated that the optical power can be divided equally for a propagation distance around 900 μm. The mathematical formulation method applied is based on the finite element method.