Electroabsorption modulator based on Wannier–Stark localization with 20 GHz/V efficiency

Abstract
We report on a ridge-waveguide modulator based on Wannier–Stark localization in an InGaAs/InAlAs superlattice. Anisotropic absorption is measured and efficient modulation is obtained in the low-field domain and in the high-field domain with TE-polarized light. The device exhibits outstanding HF characteristics: in terms of bandwidth-to-drive-voltage ratio, we find that the Wannier–Stark localization is far more efficient than the quantum Stark effect.