Microscope device for forming laser beam, comprises symmetric means, which interact with the laser beam to be formed, superposition means for positioning two sections or part beams, a double dove prism, and a laser light source

The microscope device comprises symmetric means, which interact with laser beam (2, 3) to be formed in such a way that two sections or part beams of the laser beams different in the transverse direction of the laser beam are point wisely or area wisely coherent to each other after the interaction, and superposition means for positioning the two sections or part beams, where the superposition means are arranged in the beam way of the laser beam. The two sections or part beams are mirror symmetrical to each other. The two sections are axially symmetrical to a symmetrical axis. The microscope device comprises symmetric means, which interact with laser beam (2, 3) to be formed in such a way that two sections or part beams of the laser beams different in the transverse direction of the laser beam are point wisely or area wisely coherent to each other after the interaction, and superposition means for positioning the two sections or part beams, where the superposition means are arranged in the beam way of the laser beam. The two sections or part beams are mirror symmetrical to each other. The two sections are axially symmetrical to a symmetrical axis extending itself in expansion direction of the laser beam. The symmetric means comprises a partially permeable mirror area that lets a first part beam of the laser beam and reflects a second part beam of the laser beam so that the first and second part beams form the both mirror symmetrical sections or part beams. The device further comprises a double dove prism in which the partially permeable mirror area is arranged, a laser light source for producing the laser beam, and means for reducing spatial coherence of the laser beam. The laser beam produced by the laser light source comprises no spatial coherence or a spatial coherence that is smaller than one-tenth or one-fifth or hundred of the diameter of the laser beam. The means for reducing spatial coherence of the laser beam comprises a plate with sectionally different thickness. The plate comprises points symmetrically arranged to each other that have same thickness. The plate comprises ring-shaped zones of same thickness. The microscope comprises an objective and the plate is arranged for partial extension of the optical way in the Fourier plane of the objective. An independent claim is included for a method for forming laser beam. Vorrichtung zur Formung eines Laserstrahls, umfassend Symmetrisiermittel, die derart mit dem zu formenden Laserstrahl (27) wechselwir