Abstract: The present invention is directed to a laser diode which is formed of a substrate of a semi-insulating material having a body of a semiconductor material on a surface thereof. The body includes a first layer of one conductivity type on the substrate surface, a laser active layer on the first layer and a second layer of a semiconductor material of the opposite conductivity type on the active layer. Spaced isolation regions of the one conductivity type extend through the second layer and the active layer to the first layer to electrically isolate a portion of the second layer and active layer from the remaining portions of the layers. A first contact region of the opposite conductivity type extends into the isolated portion of the second layer and has a metal contact layer in ohmic contact therewith. A second contact region of the one conductivity type extends through the second layer and active layer to the first layer outside the isolation regions.