| 摘要 |
<p>The invention relates to a device and a method for enhancing the intensity of a laser beam (29) having an intensity distribution which has an annular shape in the far field. The device comprises a resonator cavity (1, 49, 51, 57) that comprises at least four annularly closed reflective surfaces (3, 5, 7, 9, 53, 55). A first and a second reflective surface (3, 5) have a curvature defining a common focal point (21) and are arranged on opposite sides of a focal plane (23) that extends through the focal point (21). A third and a fourth reflective surface (7, 9) are arranged on opposite sides of the focal plane (23). The resonator cavity (1, 49, 51, 57) and the reflective surfaces (3, 5, 7, 9, 53, 55) are arranged such that a laser beam (29) having an intensity distribution which has an annular shape in the far field can be introduced into the resonator cavity (1, 49, 51, 57) in such a manner, that it travels on a closed resonator path inside the resonator cavity (1, 49, 51, 57) and is reflected at least three times by the reflective surfaces (3, 5, 7, 9, 53, 55) between successive transitions of the focal point (21).</p> |
