Fabrication of a waveguiding layer in Teflon AF((R)) by ion irradiation

The modification of thin Teflon AF (R) films by He+ ion irradiation was inv estigated. As an integrated optical measurement technique, leaky-mode spect roscopy has been applied, and an increase of Deltan = 8 X 10(-3) for the re al part of the refractive index has been found in the irradiated surface re gion of the film. The irradiated films can be regarded as a bilayer system consisting of a layer with low refractive index and a layer with high refra ctive index. The latter can be used as an optical waveguide with a substrat e of unmodified Teflon AF. In addition, a decrease of the initial film thic kness, an increase in UV absorption, and no significant increase in absorpt ion of near-infrared light were found. (C) 2001 Society of Photo-Optical In strumentation Engineers.