Large photo-induced index variations in chalcogenide-on-silicon waveguides

作者：Califa R; Kaganovskii Y; Munk D; Genish H; Bakish I; Rosenbluh M; Zadok A^*

来源：Optics Letters, 2014, 39(20): 5905-5908.

DOI：10.1364/OL.39.005905

The postfabrication modification of the group delay in silicon-photonic waveguides is proposed, simulated and demonstrated experimentally. Group delay variations of 2% are achieved through photo-induced changes to an upper cladding layer of photosensitive As10Se90 chalcogenide glass. The illumination of the cladding layer by intense green light for a few seconds leads to mass transfer and removal of material, away from irradiated regions. The phenomenon is employed in the localized removal of the cladding layer from above the core region of a silicon-on-insulator waveguide, thereby modifying its phase and group delays. Using the proposed method, the free spectral range of a chalcogenide-on-silicon Mach-Zehnder interferometer was modified by 1%. The technique is applicable to the postfabrication adjustment of the frequency response of silicon-photonic filters, comprised of several cascaded elements.

• 出版日期2014-10-15