DFB laser diode structure having complex optical grating coupling

A DFB laser diode structure having complex optical grating coupling, comprising:

• a laser-active layer arranged between first and second optical cladding layers made from semiconductor material of mutually opposite conductivity types;
• a first layer of an index semiconductor material in a form of volumetric material that is arranged at a side of the second optical cladding layer that faces away from the laser-active layer;
• a second layer of an absorption semiconductor material in a form of volumetric material that is arranged at a side of the first layer of index semiconductor material that faces away from the second optical cladding layer;
• an optical grating constructed in the first layer made from the index semiconductor material and the second layer made from the absorption semiconductor material, the optical grating being a relief surface which is averted from the laser-active layer and defines forward projections of the grating pointing in the direction away from the laser-active layer and backward projections of the grating pointing towards the laser-active layer;
• the first layer made from the index semiconductor material and the second layer made from the absorption semiconductor material being of mutually opposite conductivity types;
• both the first layer made from the index semiconductor material and the second layer made from the absorption semiconductor material located between the second optical cladding layer and the relief surface in the forward projections of the grating;
• a body located on a side, averted from the laser-active layer, of the relief surface, the body abutting the relief surface and made from a semiconductor material of the conductivity type of the second optical cladding layer;
• a further layer of semiconductor material in a form of volumetric material different from the index semiconductor material and absorption semiconductor material, the further layer being located in the forward projections of the grating between the first and second layers of the absorption and index semiconductor material and the relief surface;
• and
• the body adjoining the relief surface being composed of the same semiconductor material as the further layer.