A laser bar includes a semiconductor layer including a plurality of layers and includes an active zone, wherein the active zone is arranged in an x-y-plane, laser diodes each form a mode space in an x-direction between two end faces, the mode spaces of the laser diodes are arranged alongside one another in a y-direction, a trench is provided in the semiconductor layer between two mode spaces, the trenches extend in the x-direction, and the trenches extend from a top side of the semiconductor layer in a z-direction to a predefined depth in the direction of the active zone.