AN ANALYTICAL INVESTIGATION OF FOUR-LAYER DIELECTRIC OPTICAL FIBERS WITH AU NANO-COATING --- A COMPARISON WITH THREE-LAYER OPTICAL FIBERS

An analytical investigation has been presented of Au nano- coated dielectric optical flbers. The propagation constants of difierent transverse TE and hybrid EH modes are obtained corresponding to varying nano-coating thickness. It has been observed that the Au-layer has its profound efiect on the number of propagating modes in the flber, and the number of sustained modes is much reduced with the increase in Au-layer thickness. For the sake of comparative investigation, the modal behavior of three-layer dielectric flbers is also taken into account together with the Au nano-coated four-layer flber. It is reported that the Au-layer has the efiect of mode proliferation with simultaneous reduction in their propagation constant values.