| 摘要 |
The invention relates to a simple and compact laser resonator which operates, in a symmetrisiered manner, a gain element, preferably a semi-conductor laser having at least two emission directions. As a result, high output powers and/or improved beam quality and/or improved spectral properties are obtained. The laser resonator is very compact and, in the ideal place, consists of only three elements: the laser active medium (1), a cylindrical collimation lens (5) and a prisma (6) which is adapted to the angle between both of the beams (4) which is coated (see figure) by a beam divider (7) and a reinjection element (9). The gain medium (1) advantageously comprises a reinjection element (2) and an antireflection layer (3). Brewster conditions can be met such that the antireflection layers (11) are not required. The reflectivities of the elements (7) and (9) determine the relative power parts in the beams (10) and (14). When the beam divider has 50 % reflectivity, both of the reinjection branches (4) support the same power and the beam (14) generally disappears. If the separator has another reflectivity, which happens frequently (14), it can be advantageous in surpressing the beam (10) by a high reflectivity of the element (9), as represented in the part (b) of the image. According to a particulary advantageous arrangement of the invention, the gain is made of a high-power diode laser which is embodied as strip array and/or the laser resonator is embodied as an unstable resonator along the direction which is parallel to the epitaxy planes. In alternative modes of embodiment, the reinjection element (9) can also be selective on wave length, for example in the form of a grating, a dielectric filter, a holographic element or volume-Bragg grating. |
