The radiation characteristic of a semiconductor or Vertical Stack Diode Laser (hereinafter referred to as a "Vertical Stack Diode Laser") is characterized by the fact that the radiation characteristic of a semiconductor or Vertical Stack Diode Laser (hereinafter referred to as "Vertical Stack Diode Laser") is different from that of a conventional laser beam light source having a beam diameter of several millimeters having a low beam divergence in the range of several milliradians A highly divergent beam with divergence> IOOOmrad. This is caused by an output layer that is limited by the <Iiim height, which produces a large angle divergence at this height, similar to the diffraction at the opening of the crest shape. Since the expansion of the output openings in the plane perpendicular to and parallel to the active semiconductor layer is different, different beam divergence occurs in the plane perpendicular to and parallel to the active layer.
In order to obtain a Vertical Stack Diode Laser power of 20-40 W, a plurality of laser emitters are combined on a so-called laser strip to form a laser assembly. Typically 10-50 individual sets of emitters are arranged in a row in a plane parallel to the active layer. The final beam of such bars has an aperture angle of about 10 ° and a beam diameter of about IO mm in a plane parallel to the active layer. The final beam quality in this plane is many times lower than the final beam quality in the plane perpendicular to the active layer. Even if the divergence angle of the laser chip may be reduced in the future, a completely different ratio of the beam quality perpendicular to and parallel to the active layer will still be present. As a result of the aforementioned beam characteristics, the beam has a very large difference in the beam quality in both the vertical and parallel directions in the active layer. The concept of beam quality in this case is described by the M2 parameter. M2 is defined by a multiple of the beam divergence of the diode beam of the Vertical Stack Diode Laser beam that diverges above the beam diameter of the same diameter. In the above-described case, a beam diameter larger than 10,000 times the diameter of the light beam in the vertical plane is obtained in a plane parallel to the active layer. The beam divergence is different, that is, almost half the beam divergence is obtained in the plane parallel to the active layer or on the slow axis. The M2 parameter in the plane parallel to the active layer is thus greater than several orders of magnitude of the M2 value in the plane perpendicular to the active layer. One possible goal of beamforming is to obtain a speed of light having almost the same M2 value in two planes, i.e., perpendicular and parallel to the plane of the active layer. At present, there are known methods for forming beam geometries by which close beam quality is obtained in two principal planes of a beam. The use of fiber tie, by arranging the optical fiber to form a circular bar can be combined with a linear beam section. In addition, there is a technique of beam rotation in which the radiation of the individual emitters is rotated by 90 ° to thereby re-arrange in which the light beam is arranged in the direction of the axis of the higher beam quality. The following devices are known for this method, US5168401, EP0484276, DE4438368. All of these methods have one thing in common, i.e., after collimation, the radiation of the Vertical Stack Diode Laser is rotated by 90 ° in the fast axis direction to perform slow axis collimation using a common cylindrical optics. As a modification of the method, a continuous linear light source is also feasible (i.e., the high surface density, the kind of Vertical Stack Diode Laser collimated in the fast axis direction) whose beam profile (line) is split after the optical element and And then arranged in the form of existence. In addition, the rearrangement of the radiation of the individual emitters can be performed without any rotation of the beam, where the rearrangement of the radiation is achieved, for example, by parallel misalignment (displacement) using parallel mirrors. Devices that use the repositioning technique are also described in DE 1954488. In this case, the radiation of the Vertical Stack Diode Laser strip is deflected in different planes and is collimated there separately. The drawbacks of this prior art can be summarized in particular in optical fiber coupled Vertical Stack Diode Lasers where light beams having very different beam masses in both axial directions are typically coupled into the optical fiber. In the case of a circular fiber, this means that the possible numerical aperture or fiber diameter is not used in one axial direction. This results in a significant loss of power density, which in practice is limited to about 104 W / cm. In the known method described above, the difference in path length in some cases must be further compensated. This is done primarily by compensating only the defect to a limited degree of calibration prism. Multiple reflections impose additional requirements on alignment accuracy, manufacturing tolerances, and component stability. The reflective optics (e.g. made of copper) have a high absorption value. It is further known that a laser optical system of a pattern forming type for reconstructing at least one laser beam tie using at least two optical reshaping elements continuously distributed on a beam path is configured as a so-called flat panel. In the known Vertical Stack Diode Lasers, the radiated power of the Vertical Stack Diode Laser device is limited and is particularly limited by the available laser strips with a limited length, such as the length of about IOmm on their slow axis (plane of the emissive layer) The typical light output power of the laser strip is, for example, within the range of 250 watts maximum. Due to the fact that the heat sinks are used in the laser diode device to be used in particular the heat sinks of the support of the laser strips in the fast axis direction, in which the laser strips provide offset relative to each other in a stack-like manner, The need for optical elements for fast axis collimation is provided on the individual laser strips, so that the stack density of the laser strips is limited in the stack comprising these laser strips and ancillary supports or heat exchangers.