neodymium yag laser device, in particular for ophthalmic treatment

摘要

PCT No. PCT/DE84/00227 Sec. 371 Date Jun. 27, 1985 Sec. 102(e) Date Jun. 27, 1985 PCT Filed Oct. 29, 1984 PCT Pub. No. WO85/01870 PCT Pub. Date May 9, 1985.A neodymium-YAG laser is described, which can be used for ophthalmological treatment. The laser has a laser beam guide, in which the laser beam is guided as a parallel beam over a long distance and following the latter is focused onto the operating plane by a focusing optics. According to the invention, an afocal system with a plurality of optical components is placed in the parallel optical path at a distance of more than approximately 50 cm from the focusing optics. This afocal optical system substantially does not influence the beam in its normal position. As a result of an optical component in the afocal system, which is displaceable, it is possible to vary the angle of the marginal beams of the focused beam. According to the preferred embodiment, the afocal system has two single lenses, whereof one has a positive and the other a negative refractive power and one is displaceable.