| 摘要 |
In the case of a deformable mirror (11) with a mirror plate (13) which is in glass form in particular for high laser frequencies and an axial actuator (20) which concentrically engages the rear side of the mirror surface (17)-with a reduced actuator stroke movement for the same dome-like configuration height-the dome configuration of the convex curvature of the mirror surface (17) is now of larger area and at the same time better approximated to the desirable sphere if, instead of the central application of force, the arrangement provides for decentral application of force at diametrally opposite locations. For that purpose the actuator (20) operates on a ring (25) which is disposed behind the mirror plate 13 and which is preferably integral with the mirror plate (13). If the application of pressure to the rear side of the mirror plate (13) is not along a circular ring but a ring (25) which is of elliptical cross-section, then astigmatism effects are reliably avoided even with large angles of beam incidence. Besides being influenced by way of the cross-sectional geometry of the ring (25), the sphere of the mirror surface (17) can also be influenced by way of a centrally symmetrical weakening or reduction in thickness of the mirror plate (13), and also by a static increased pressure in a fluid-filled chamber (26) behind the mirror plate (13). Heat losses which occur in the mirror plate (13) are dissipated by way of the fluid filling of the chamber (26) and the relatively flexurally stiff rear wall (29) thereof, which is a good conductor of heat, into a heat exchange chamber (30) disposed therebehind as a heat sink, of a volume which is variable in dependence on pressure, and carried away with the forced circulation of a cooling agent (31) flowing therethrough.
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