Buried heterostructure laser modulator

摘要

A buried-heterostructure laser modulator for modulating a laser beam includes two adjacent thin epitaxial first layers of oppositely doped semi-conductor material and a thin epitaxial buried layer of undoped semi-conductor material located between the two adjacent first layers. The buried layer forms a single mode optical channel having a width larger than a height thereof with the width equal to or greater than a width of a diffraction limited waveguide mode of the laser beam. Two thin epitaxial second layers of similarly and heavily doped semiconductor material are provided respectively adjacent the respective first layers of the same doping. One of these second layers is provided on a side of a semi-insulating substrate and two strip lines of opposite bias are provided on the side of the substrate and connect to a respective second layer of the same bias. The two adjacent first layers are preferably AlGaAs and the buried layer is preferably GaAs with a width less than about 1.5 microns and a height about 0.2 microns.