Linear phase modulation is a critical characteristic of state-of-the-art modulators in
coherent optical communication systems. Currently the majority of silicon modulators
being developed are based on the plasma dispersion effect since silicon's centrosymmetric
crystal structure prohibits the Pockels (or linear electro-optic) effect. The
plasma dispersion effect is nonlinear with speed limited by charge mobility. Recently it
was shown that by applying an anisotropic strain to silicon waveguides, the symmetry of
the crystal structure can be broken, hence, artificially inducing the
In this dissertation we investigate the strain induced Pockels effect in silicon waveguides.
We introduce a Figure of Merit (FOM) that characterizes the Pockels effect in various
silicon waveguides and show the proposed FOM has an excellent correlation with the
experimentally obtained second order nonlinearity χ(2). A six-fold improvement of FOM
can be achieved by optimizing the waveguide cross-section and tuning the mechanical
properties of the straining layer.