Semiconductor laser with reduced heat loss

1. A semiconductor laser having a semiconductor chip which contains an active layer and emits radiation in a main radiating direction, wherein the active layer is structured in a direction perpendicular to the main radiating direction to reduce heating of the semiconductor chip by spontaneously emitted radiation, and the active layer has the form of a mesa, the mesa comprising side walls having a reflection-reducing layer.

2. The semiconductor laser according to claim 1 , wherein the semiconductor laser is a disc laser.

3. The semiconductor laser according to claim 2 , wherein the disc laser has an external resonator.

4. The semiconductor laser according to claim 1 , wherein the active layer has a region provided for optical pumping by a pump radiation source.

5. The semiconductor laser according to claim 4 , wherein the active layer has the form of a mesa, and the width of the mesa in a direction perpendicular to the main radiating direction of the semiconductor laser is approximately as large as the width of the optically pumped region.

6. The semiconductor laser according to claim 1 , wherein the laser contains a heat sink.

7. The semiconductor laser according to claim 6 , wherein no substrate is contained between the heat sink and the active layer.

8. The A semiconductor laser comprising a semiconductor chip which contains an active layer and emits radiation in a main radiating direction, wherein the active layer is structured in a direction perpendicular to the main radiating direction to reduce heating of the semiconductor chip by spontaneously emitted radiation;

wherein the active layer has the form of a mesa, the mesa comprising side walls that extend parallel or obliquely to the main radiating direction, and the side walls comprising a reflection-reducing layer.