Internal biasing by δ-doping for low-voltage, high-bandwidthquantum-well optical modulators

Optical intensity modulators must exhibit low-voltage operation, low insertion loss, high contrast ratio and high electrical bandwidth. Electroabsorption calculations for semiconductor quantum wells predict that internal biasing by strategic δ-doping can produce greatly improved low-voltage operation in waveguide or normal-incidence modulators, for a specified insertion loss and contrast ratio, without compromising electrical bandwidth. Growth of strategically δ-doped electrorefractive intensity modulators is shown computationally to be insensitive to nonreproducibility in layer growth. Internal biasing by strategic doping is of potential value across the whole range of modulator applications