Abstract: The invention relates to an AlInGaN alloy based superluminescent diode, comprising a gallium nitride bulk substrate, a lower cladding layer with n-type electrical conductivity. Further it includes a lower light-guiding layer with n-type electrical conductivity, a light emitting layer, an electron blocking layer with p-type electrical conductivity, an upper light-guiding layer, an upper cladding layer with p-type electrical conductivity, and a subcontact layer with p-type electrical conductivity. The gallium nitride bulk substrate has a spatially varying surface misorientation in the relation to the crystallographic plane M in range of 0° to 10°.

Abstract: The invention relates to an AlInGaN alloy based laser diode, which uses a gallium nitride substrate. It also includes a lower cladding layer, a lower light-guiding layer-cladding, a light emitting layer, an upper light-guiding-cladding layer, an upper cladding layer, and a subcontact layer. The lower light-guiding-cladding layer and the upper light-guiding-cladding layer have a continuous, non-step-like and smooth change of indium and/or aluminum content.