The lateral leakage current restriction in the lateral direction of ridge diode lasers

The lateral leakage current is influenced by the height of ridge waveguide. We design two structures to restrict the lateral leakage current of ridge diode lasers, called ‘step-ridge’ structure and ‘groove-ridge’ structure. In order to obtain a better output electrical characteristic, we optimize the geometry of the two structures. For ‘step-ridge’ structure, we simulate various step-widths (including up-step widths and down-step widths). For ‘groove-ridge’ structure, we simulate different widths of groove and distances between injection section and groove. The lateral leakage currents of both two structures were calculated under the same injection current. In conclusion, both two structures can effectively reduce the leakage carrier by at most 80%, the ‘step-ridge’ diode lasers can improve around 6.5% wall-plug efficiency, but the ‘groove-ridge’ diode lasers would reduce the wall-plug efficiency at the same time.