Passivation of the resonator end faces of semiconductor lasers based on iii-v semiconductor material

摘要

Passivation of the resonator end faces of semiconductor lasers based on III-V semiconductor material ;The invention deals with the passivation of the resonator end faces, in particular the cleaved edges of semiconductor laser diodes, by high-temperature epitaxy of the quaternary compound semiconductor In_xGa_1xAs_yP_1y, with all stoichiometrically possible compounds being included, namely (01 and 0y1). To passivate the In_xGa_1xAs_yP₁y, it is then possible for an additional passivation layer to be applied in situ, i.e. in the epitaxy installation or in a directly connected installation. In a device according to the invention, the semiconductor crystal is brought to the temperature required for the epitaxy by being heated. To avoid thermal destruction of the contact metal during the epitaxy, the process sequence which has been employed hitherto is modified in such a way that the metal is only deposited after the cleaving operation and the passivation. The deposition of the metal on the passivated laser bar is carried out by means of special equipment which allows deposition of metal on the entire surface of the laser and at the same time prevents vapour deposition on the cleaved edges. The application of the invention relates to the production of high-power laser diodes. The effect of the passivation according to the invention manifests itself in a significant increase in the service life of the laser diode with a high optical output of laser light which emerges from the passivated mirror facets. A special application comprises the production of high-load, reliable pump lasers for erbium-doped fibre amplifiers.