Improved extinction ratio of waveguide electroabsorption optical modulators induced by an InGaAs absorbing layer

The authors demonstrate theoretically and experimentally that the extinction ratio of an InGaAsP waveguide electroabsorption optical modulator can be greatly improved by adding an InGaAs absorbing layer. They use both a simplified slab waveguide analysis and the full three-dimensional beam propagation method to study the light propagation in such modulators. The predicted increase in extinction ratio is then experimentally demonstrated in fabricated devices. The calculations are extended to a modulator integrated to a laser.