Radial polarization-rotating optical arrangement and microlithographic projection exposure system incorporating said arrangement
AssigneeCarl-Zeiss-Stiftung
InventorKarl-Heinz Schuster
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Abstract
An optical arrangement is disclosed wherein an entering beam is converted into an exiting beam having a total cross section of light which is linearly polarized essentially in the radial direction by rotation. For this purpose, rasters of half-wave plates (41, 42, 4i), a combination of birefringent quarter-wave plate 420 and a circular plate 430 is suggested in combination with a conical polarizer 21′. This arrangement is preferably utilized in the illumination portion of a microlithographic projection exposure system. It is important that the arrangement be mounted behind all asymmetric or polarizing component elements 103a.
Claims5
An optical arrangement comprising:
- an optical structure for receiving an entering light beam;
- said entering light beam having a linear polarization (P) in a predetermined direction;
- said optical structure being adapted to non-subtractively rotate the polarization of said entering light beam into an exiting light beam having linear polarization essentially directed radially;
- and,
- said entering light beam defining an optical axis (A) and said optical structure including more than four half-wave plates disposed in a raster, segment or facet configuration in a common plane;
- said half-wave plates having respective preferred directions so arranged that each half-wave plate rotates the polarization direction of the penetrating linear polarized light in the direction of a radius which cuts through the corresponding half-wave plate and is directed to said optical axis.
An optical arrangement comprising:
- an optical structure for receiving an entering light beam;
- said optical structure being adapted to convert said entering light beam into an exiting light beam having linear polarization essentially directed radially wherein a direction of polarization is rotated;
- said entering light beam defining an optical axis (A) and said optical structure including more than four half-wave plates disposed in a raster, segment or facet configuration;
- said half-wave plates having respective preferred directions so arranged that each half-wave plate rotates the polarization direction of the penetrating linear polarized light in the direction of a radius which cuts through the corresponding half-wave plate and is directed to said optical axis;
- a reflective polarizer having a conical surface shaped polarizing surface or a conical-frustrum surface shaped polarizing surface;
- and,
- said half-wave plates being mounted in the beam path of light reflected at said reflective polarizer.
Dependencies are inferred from the claim text.