Apparatus for manipulation of an optical element

Abstract

The invention relates to an apparatus for manipulation of an optical element in up to six degrees of freedom with respect to a structure via at least three actuator devices. The actuator devices each have at least two force-controlled actuators, which each produce an effective force along one degree of freedom, with linking points of the actuator devices acting directly on the optical element.

1 - 43 . (canceled) 
   
   
       44 . A hexapod kinematic mounting, comprising:
 a base defining a base plane;   a platform situated relative to the base and movable relative to the base; and   six legs each having nominally identical length and a respective leg axis, the legs having substantially equal stiffness and being arranged in three pairs of legs extending between the base and platform and supporting the platform relative to the base, each pair of legs having first and second ends, the first ends of each pair being coupled together in a A-shaped manner forming a respective apex and the respective second ends being splayed relative to the apex, the apices being situated substantially equidistantly from each other at respective locations on a circle on the platform, and the respective second ends of the pairs of legs being mounted at respective locations on a circle on the base such that the respective axes of each pair of legs define a respective leg plane that is substantially perpendicular to the base plane, each leg comprising an actuator serving, when energized, to change a length of the respective leg such that a coordinated energization of the respective actuators in selected legs produces a desired movement of the platform relative to the base in all six degrees of freedom of motion.   
   
   
       45 . The mounting of  claim 44 , wherein the respective legs of each pair form an angle of substantially 109.5° at the respective apex. 
   
   
       46 . A kinematically mounted optical element, comprising:
 an optical element;   a base defining a base plane;   a platform movable relative to the base;   at least one hold affixing the optical element to the platform; and   a hexapod situated between the base and the platform so as to support the platform relative to the base, the hexapod comprising six legs each having a respective leg axis, the legs having nominally identical length and substantially equal stiffness and being arranged in three pairs each having first and second ends, the first ends of each pair being coupled together in a A-shaped manner forming a respective apex and the respective second ends being splayed relative to the apex, the apices being situated substantially equidistantly from each other at respective locations on a circle on the platform, and the respective second ends of the pairs of legs being mounted at respective locations on a circle on the base such that the respective axes of each pair of legs define a respective leg plane that is substantially perpendicular to the base plane, each leg comprising an actuator serving, when energized, to change a length of the respective leg such that a coordinated energization of the respective actuators in selected legs produces a desired movement of the platform relative to the base in all six degrees of freedom of motion.   
   
   
       47 . The optical element of  claim 46 , wherein the optical element is a mirror. 
   
   
       48 . The optical element of  claim 46 , wherein the respective legs of each pair form an angle of substantially 109.5° at the apex. 
   
   
       49 . An optical system, comprising:
 a frame;   a base mounted to the frame and defining a base plane;   a platform movable relative to the base; an optical element mounted to the platform; and   a hexapod situated between the base and the platform so as to support the platform relative to the base, the hexapod comprising six legs each having a respective leg axis, the legs having nominally identical length and substantially equal stiffness and being arranged in three pairs each having first and second ends, the first ends of each pair being coupled together in a A-shaped manner forming a respective apex and the respective second ends being splayed relative to the apex, the apices being mounted equidistantly from each other at respective locations on a circle on the platform, and the respective second ends of the pairs of legs being mounted at respective locations on a circle on the base such that the respective axes of each pair of legs define a respective leg plane that is substantially perpendicular to the base plane, each leg comprising an actuator serving, when energized, to change a length of the respective leg such that a coordinated energization of the respective actuators in selected legs produces a desired movement of the platform relative to the base in all six degrees of freedom of motion.   
   
   
       50 . The optical system of  claim 49 , wherein the respective legs of each pair form an angle of substantially 109.5° at the apex. 
   
   
       51 . The optical system of  claim 49 , further comprising at least one monitor situated and configured to measure and monitor position of the optical element relative to a fixed reference. 
   
   
       52 . The optical system of  claim 49 , wherein the optical element is a reflective optical element. 
   
   
       53 . The optical system of  claim 49 , wherein the optical system is an EUVL optical system. 
   
   
       54 . The optical system of  claim 53 , wherein the optical system is an EUVL projection-optical system. 
   
   
       55 . The optical system of  claim 49 , wherein: the optical system comprises multiple optical elements; and at least one optical element is mounted to the frame by a respective base, platform, and hexapod. 
   
   
       56 . A kinematically mounted optical element, comprising:
 an optical element;   a base defining a base plane;   a platform movable relative to the base;   at least one hold affixing the optical element to the platform; and   a hexapod situated between the base and the platform so as to support the platform relative to the base, the hexapod comprising six legs each having a respective leg axis, the legs having nominally identical length and being arranged in three pairs each having first and second ends, the first ends of each pair being coupled together in a A-shaped manner forming a respective apex and the respective second ends being splayed relative to the apex, the apices being mounted equidistantly from each other at respective locations on a circle on the platform, and the respective second ends of the pairs of legs being mounted at respective locations on a circle on the base such that the respective axes of each pair of legs define a respective leg plane that is substantially perpendicular to the base plane, each leg comprising an actuator serving, when energized, to change a length of the respective leg such that a coordinated energization of the respective actuators in selected legs produces a desired movement of the platform, with substantially no cross-coupling, relative to the base in all six degrees of freedom of motion.   
   
   
       57 . The optical system of  claim 56 , wherein the legs have substantially equal stiffness. 
   
   
       58 . The optical system of  claim 56 , wherein the respective legs of each pair form an angle of substantially 109.5° at the apex. 
   
   
       59 . An optical system, comprising an optical element as recited in  claim 56 . 
   
   
       60 . A hexapod kinematic mounting, comprising:
 a base defining a base plane;   a platform situated relative to the base and movable relative to the base; and   six legs each having nominally identical length and a respective leg axis, the legs being arranged in three pairs of legs extending between the base and platform and supporting the platform relative to the base, each pair of legs having first and second ends, the first ends of each pair being coupled together in a A-shaped manner forming a respective apex and the respective second ends being splayed relative to the apex such that the respective legs of the pair form an angle of substantially 109.5° at the apex, the apices being mounted equidistantly from each other at respective locations on a circle on the platform, and the respective second ends of the pairs of legs being mounted at respective locations on a circle on the base such that the respective axes of each pair of legs define a respective leg plane that is substantially perpendicular to the base plane, each leg comprising an actuator serving, when energized, to change a length of the respective leg such that a coordinated energization of the respective actuators in selected legs produces a desired movement of the platform relative to the base in all six degrees of freedom of motion.