A Distributed Feedback Laser comprises a layer stack comprising a p-layer, an n-layer which are arranged so as to form an pn-junction having an active layer in between. Within the layer stack, an index coupled grating layer or a grating layer is arranged which comprises a first, a second, and a third grating portion. The first, the second, and the third grating portions are asymmetrically arranged along a lateral dimension of the layer stack, wherein the second grating portion is formed without a grating structure.