Patent ID: 8079721

Claim:
A mirror assembly for an optical system of a laser machining tool, the mirror assembly comprising: an adaptive mirror; and a magnetorheological or electrorheological fluid valve defined at least in part by a flow channel for passing a magnetorheological or electrorheological fluid, respectively, the flow channel being delimited on a side of a housing by the adaptive mirror, wherein the adaptive mirror is deformable by changing a pressure within the flow channel when actuating the fluid valve, wherein the electrorheological fluid valve comprises electrodes and is configured to be actuated, during operation of the mirror assembly, by applying an electrical field between the electrodes to change a viscosity of the electrorheological fluid, and wherein the magnetorheological fluid valve comprises a coil for generating a magnetic field in the flow channel and is configured to be actuated, during operation of the mirror assembly, by adjusting the current through the coil to adjust the magnetic field in the flow channel to change a viscosity of the magnetorheological fluid.