Surface-emitting laser diode

A tunable surface-emitting laser diode, comprising:

• a central layer;
• two layers separated by said central layer, said two layers being arranged parallel, and with reference to planes of said two layers, transverse to one another and being made from semiconductor materials having different energy band gaps, and of which one is provided as an active layer and one as a tuning layer;
• contacts connected in an electrically conductive fashion to said two layers in such a way that a separate current injection into the active layer and into the tuning layer can be performed;
• a semiconductor layer on said two layers and having a surface defining a spatial periodic structure which is present in a region, arranged with reference to the planes of said two layers in a fashion transverse to a region provided for generating radiation in the active layer;
• a metallic film at least partially covering said spatial periodic structure;
• said spatial periodic structure being of a height and a length of each period of said spatial periodic structure, a minimum distance of said metallic film from the active layer, and a thickness of said metallic film being dimensioned such that during operation of the laser diode surface modes are excited by photons generated in the active layer on a surface of said metallic film averted from the active layer, and
• means for achieving laser resonance during operation of said laser diode, said means for achieving a laser resonance comprising at least one reflective coating arranged parallel and with reference to the planes of said two layers transverse to the active layer.