OPTICAL FIBER-POLYMER GUIDE COUPLING BY A TAPERED GRADED-INDEX GLASS GUIDE

A new four layer tapered coupler (FLTC) has been studied and tested, a ble to transfer light efficiently from a monomode fiber to a polymer f ilm guide by means of an auxiliary graded index glass waveguide, A sim ple theory has been developed to calculate the maximum efficiency of t hese structures. Experiments have been performed; at lambda = 1.321 mu m, on several FLTC samples, containing K+-Na+ ion-exchanged glass wav eguides and spin coated poly-3BCMU films, Insertion losses in the rang e 3-6.5 dB have been measured, depending on the taper configuration, T he agreement between theoretical: and experimental data is good, provi ded that a suitable ripple of the taper profile is assumed, The applic ation of the new coupler to future integrated waveguide systems, inclu ding passive glass components and polymer based all optical devices, i s assessed.