Simple design of edge-emitting diode laser to overcome thermal lens effect

Parameters of two-element, index-guided laser structure providing single-mode operation at high power are found numerically. 3-D numerical code has been implemented, which takes into account carrier diffusion in the quantum well, edge radiation losses and thermal lens effect. Within the simulation, higher-order optical modes on a `frozen background´ are computed. The onset of threshold for higher-order modes puts an upper limit on the range for stable, single-mode operation. Then, for the 5 μm-core and 2 mm-length device, stable, single-mode operation up to Watt-level output power is predicted with laser efficiency growing as a function of drive currents.