  We describe an opto-electronic structure in which charge and spin degrees of
freedom in electrical gate-defined quantum dots can be coherently coupled to
light. This is achieved via electron-electron interaction or via electron
tunneling into a proximal self-assembled quantum dot. We illustrate potential
applications of this approach by considering several quantum control
techniques, including optical read-out of gate-controlled semiconductor quantum
bits and controlled generation of entangled photon-spin pairs.
