Abstract: A semiconductor laser diode has a short period substantially intrinsic superlattice structure. The superlattice is constructed from alternating layers of substantially intrinsic direct and indirect semiconductor material. Semiconductor electrodes, one being p-type and the other being n-type, are each formed adjacent a respective opposite lateral surface of the superlattice. The electrodes are biased to inject carriers into the superlattice. At the top and bottom surfaces of the superlattice, a semiconductor layer is formed, one layer being n-type and the other being p-type. These layers are biased by an intermittent voltage to develop an intermittent field across the superlattice. This field transforms the indirect material to direct material. The recombination of carriers in the quantum well when the material becomes direct develops optical radiation to be emitted.