Laser diode apparatus having a plurality of active regions (4a... 4n) which are arranged laterally alongside one another and are suitable for radiation production, wherein - the active regions (4a... 4n) are formed in semiconductor bodies (5a... 5n) separated from one another by a free space, wherein each semiconductor body (5a... 5n) is an edge-emitting laser structure, - the active regions (4a... 4n) are arranged on a common substrate, which is formed from the growth substrate for the active regions, - all the active regions (4a... 4n) emit laser radiation during operation, - the laser diode apparatus has at least two side surfaces (9, 10) which laterally bound the laser diode apparatus, - the active regions (4a... 4n) are arranged axially symmetrically with respect to an axis of symmetry of the laser diode apparatus, wherein the axis of symmetry runs perpendicular to a lateral main extent direction of the laser diode apparatus and parallel to that surface of the substrate on which the active regions (4a... 4n) are arranged, a lateral size (ba... bn) of the active regions varies in the lateral direction, and the lateral size of the active regions decreases with increasing distance from the closest side surface in the direction of the axis of symmetry, such that the lateral size (ba... bn) of one active region (4a... 4n) in the region of the closest side surface is greater than the lateral size of a further active region which is adjacent to the first active region and is further away from the closest side surface (9, 10) than the first active region, and - the laser diode apparatus has during operation an operating temperature distribution over different active regions (4a... 4n) along the main extent direction of the laser diode apparatus which is more homogeneous than in the case of a further laser diode apparatus having active regions arranged at equal intervals, and each of the same lateral size. - the active regions (4a... 4n) are formed in semiconductor bodies (5a... 5n) separated from one another by a free space, wherein each semiconductor body (5a... 5n) is an edge-emitting laser structure, - the active regions (4a... 4n) are arranged on a common substrate, which is formed from the growth substrate for the active regions, - all the active regions (4a... 4n) emit laser radiation during operation, - the laser diode apparatus has at least two side surfaces (9, 10) which laterally bound the laser diode apparatus, - the active regions (4a... 4n) are arranged axially symmetrically with respect to an axis of symmetry of the laser diode apparatus, wherein the axis of symmetry runs perpendicular to a lateral main extent direction of the laser diode apparatus and parallel to that surface of the substrate on which the active regions (4a... 4n) are arranged, a lateral size (ba... bn) of the active regions varies in the lateral direction, and the lateral size of the active regions decreases with increasing distance from the closest side surface in the direction of the axis of symmetry, such that the lateral size (ba... bn) of one active region (4a... 4n) in the region of the closest side surface is greater than the lateral size of a further active region which is adjacent to the first active region and is further away from the closest side surface (9, 10) than the first active region, and - the laser diode apparatus has during operation an operating temperature distribution over different active regions (4a... 4n) along the main extent direction of the laser diode apparatus which is more homogeneous than in the case of a further laser diode apparatus having active regions arranged at equal intervals, and each of the same lateral size.