A semiconductor laser which can be highly modulated and a method for its production are specified. The semiconductor laser has a substrate (1), a semiconductor layer stack (4) and electrical contacts (6, 7). In order to reduce the capacitance, the width of the semiconductor layer stack (4) on the side surfaces (10) is reduced by anisotropic etching. The electrical contacts (6, 7) are located on the same side of the substrate (1) and are applied in the same process step. The semiconductor laser is suitable for monolithic integration with other components. <IMAGE>
