Optical apparatus comprising an optical component and an adjustment device and method for influencing a polarization state of the optical component

1. An optical apparatus, comprising

an optical component having at least one optical surface and a first optical axis,

a socket in which said optical component is mounted, and

first manipulators arranged to exert forces approximately parallel to said optical axis of said optical component for varying stresses in said optical component, said forces having a strength such that stress birefringence is induced in said component;

said optical component being a first optical component, and further comprising at least a second optical component having at least one optical surface and a second optical axis, and further comprising second manipulators arranged to exert second forces approximately parallel to said second optical axis of said second optical component for varying stresses in said second optical component, said second forces having a strength such that at least predominantly a scalar effect on imaging properties in said second optical component is induced.

2. The apparatus of claim 1 , wherein said second forces are different from said first forces.

3. The apparatus of claim 1 , wherein said first optical component comprises a material having a lower strain-optical coefficient than said second optical component.

4. The apparatus of claim 1 , wherein said first optical component has a shape which is different from a shape of said second optical component.

5. The apparatus of claim 1 , wherein said first optical component is a first lens, and said second optical component is a second lens, wherein said second lens has a thickness different form a thickness of said first lens, and wherein a refractive power of said first lens is at least approximately equal a refractive power of said second lens.

6. A method for influencing a polarization state of at least one optical component in a microlithographic projection exposure apparatus, said at least one optical component having an optical axis, comprising

exerting forces on said at least one optical component such that stress birefringence is induced in said at least one optical component; wherein said at least one optical component is a first optical component, and

exerting forces on at least a second optical component such that a scalar effect on imaging properties of said second optical component is produced in said second optical component which scalar effect at least partially compensates a scalar effect induced by said forces exerted on said first optical component.

7. The method of claim 6 , wherein said forces exerted on said second optical component are lower than or equal the forces exerted on said first optical component.

8. The method of claim 6 , wherein said first component comprises a material having a lower strain-optical coefficient than said second optical component.

9. The method of claim 6 , wherein said first optical component has a shape which is different from a shape of said second optical component.

10. The method of claim 6 , wherein said first optical component is a first lens, and said second optical component is a second lens, wherein said second lens has a thickness different from a thickness of said first lens, and wherein a refractive power of said first lens is at least approximately equal a refractive power of said second lens.