A laser diode includes a substrate and a junction layer disposed on the substrate. The junction layer forms a quantum well of the laser diode. The laser diode includes a junction surface having at least one channel that extends through the junction layer to the substrate. The at least one channel defines an anode region and a cathode region. A cathode electrical junction is disposed on the junction surface at the cathode region, and an anode electrical junction is disposed on the junction surface and coupled to the junction layer at the anode region. A cathode metal layer is disposed in at least a trench region of the channel. The cathode metal layer couples the substrate to the cathode electrical junction.