Strained germanium silicon optical modulator array including stress materials

Abstract

An integrated optical modulator array useful for modulating light at different wavelengths in the same optical band includes multiple GeSi waveguides on a substrate. Each GeSi waveguide has a different width and is coupled to electrodes to form an electro-absorption modulator. A stressor material, such as SiN, disposed between the GeSi waveguides in the optical modulators applies a strain to the GeSi waveguides. Because each GeSi waveguide has a different width, it experiences a different strain. This difference can be a difference in magnitude, type (homogeneous v. inhomogeneous, compressive v. tensile), or both. The different strains shift the bandgaps of the Ge in the GeSi waveguides by different amounts, shifting the optical absorption edges for the GeSi waveguides by different amounts. Put differently, the stressor layer strains each GeSi modulator differently, causing each GeSi modulator to operate at a different wavelength.