Effect of glow discharge plasma on step index polymer optical ber parameters

Abstract

DC glow discharge plasma of power 40 W was applied to step index polymer optical bers for differentexposure times. Nitrogen, oxygen, and hydrogen gases were used to obtain the glow discharge. The ber core materialwas poly methyl methacrylate and the cladding was uorinated polymer. The effect of plasma on the optical parameters,such as core index pro le, cladding index, and the numerical aperture, was studied by multiple beam interference fringesand Fourier transformation of infrared spectroscopy spectra. It was found that the plasma treatment affected the opticalparameters of both the cladding and the core regions of optical bers. The optical parameters also changed with thetreatment time. The hydrogen plasma had effects greater than those of nitrogen and oxygen plasma. These observedresults can be explained by the effect of the electric eld during plasma treatment. The studied optical bers afterplasma treatment can be used as inverted-graded index with its important applications.