MODAL DISPERSION-CURVES OF AN OPTICAL-FIBER WITH A TREFOIL CROSS-SECTION UNDER THE WEAK GUIDANCE APPROXIMATION

We consider the dispersion curves for some lower order modes sustained by a fiber whose guiding region has a trefoil-like cross-section. Suc h a fiber resembles a multicore structure in which three cores are emb edded in a common cladding. From the characteristic equation obtained under the weak guidance approximation, the dispersion curves are obtai ned and interpreted.