An optically pumped semiconductor laser apparatus. The apparatus includes a vertical emitter which has a central waveguide and a quantum well structure which is arranged within the central waveguide and has at least one quantum layer. The apparatus also includes a pump radiation source, which optically pumps the quantum well structure and comprises at least one pump waveguide in which the pump radiation is guided. The width of the central waveguide is greater than the width of the pump waveguide, with the width of the central waveguide and the width of the pump waveguide being matched to one another such that the quantum well structure of the vertical emitter is pumped uniformly.