“…First, our propagation model makes minimal assumptions on the electromagnetic fields in question, unlike the scalar beam propagation method (BPM, see [53,58,48,64,4] and references therein), which assumes a polarization maintaining propagation of the electromagnetic fields in an optical fiber, whereas our treatment is truly vectorial. Though both semi-vectorial and full vectorial BPM approaches have already been implemented (see [36,37,56,57,26] and references therein), we are introducing a fiber model that is a full boundary value problem rather than an initial value problem. In addition, we employ 3D isoparametric curvilinear elements to model the curved fiber (core and inner cladding) geometry, which can also later be used for studying microstructure fibers or hollow-core gas-filled fiber lasers.…”