Electro-nanomechanically actuated integrated-optical Mach-Zehnder interferometer

Abstract

We report on intensity modulation with Mach-Zehnder interferometers comprising Si3N4 rib waveguides on oxidized silicon wafers (SiO2/Si) as substrates. No electro-optic materials are required. The phase shifts are induced nanomechanically by varying the width d of an air gap between a dielectric plate E and a section of a rib waveguide [1]. The "effective-refractive-index-shifting" element E is realized in the form of a cantilever fabricated by etching of oxidized silicon wafers (SiO2/Si); the cantilever is elastically deflected under electrostatic forces.