Abstract

An electrooptic (EO) polymer was used to fabricate phase modulators and Mach-Zehnder modulators on Si wafers. This glassy polymer is from a class of nonlinear, optical materials that have large EO coefficients, low dielectric constants, and small dispersion from dc to optical frequencies. The modulators were fabricated on Si wafers using conventional IC manufacturing equipment. Three polymer layers were deposited: a hard acrylate cladding layer, followed by an EO polymer from Akzo Research, by¹ then another cladding layer. The waveguides were photobleached using an IC mask aligner, and microstrip electrodes were formed by gold plating. The active polymer layer was poled² through the cladding, and waveguide end faces were prepared by cleaving. The Mach-Zehnder modulator was designed so that each arm could be modulated independently with a separate 50-Ω microstrip electrode; the modulator response was measured up to 20 GHz. Data from each type of modulator are presented. These devices illustrate that polymers offer certain advantages over standard inorganic EO materials, such as LiNbO₃ and GaAs, in that multilayer integrated optical circuits can be fabricated on top of electronic substrates using processes and equipment that are largely in place for manufacturing integrated circuits.

© 1991 Optical Society of America