A semiconductor laser includes a layer structure with superimposed layers with at least the following layer structure: an n-doped outer layer, a third wave-guiding layer, an active zone in which light-generating structures are arranged, a second wave-guiding layer, a blocking layer, a first wave-guiding layer, a p-doped outer layer. The first, second and third wave-guiding layers have at least AlxInyGa (1−x−y) N. The blocking layer has an Al content which is at least 2% greater than the Al content of the adjacent first wave-guiding layer. The Al content of the blocking layer increases from the first wave-guiding layer towards the second wave-guiding layer. The layer structure has a double-sided gradation. The double-side gradation is arranged at the height of the blocking layer such that at least one part of the blocking layer or the entire blocking layer is of greater width than the first wave-guiding layer.