Strain-induced enhancement of plasma dispersion effect and free-carrier absorption in SiGe optical modulators.

ABSTRACT: The plasma dispersion effect and free-carrier absorption are widely used to change refractive index and absorption coefficient in Si-based optical modulators. However, the weak free-carrier effects in Si cause low modulation efficiency, resulting in large device footprint and power consumption. Here, we theoretically and experimentally investigate the enhancement of the free-carrier effects by strain-induced mass modulation in silicon-germanium (SiGe). The application of compressive strain to SiGe reduces the conductivity effective mass of holes, resulting in the enhanced free-carrier effects. Thus, the strained SiGe-based optical modulator exhibits more than twice modulation efficiency as large as that of the Si modulator. To the best of our knowledge, this is the first demonstration of t

SUBMITTER: Kim Y 

PROVIDER: S-EPMC3986731 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature