×

POLARIZATION CONVERTING UNIT, ILLUMINATION OPTICAL SYSTEM, EXPOSURE APPARATUS, AND DEVICE MANUFACTURING METHOD

  • US 20110037962A1
  • Filed: 06/23/2010
  • Published: 02/17/2011
  • Est. Priority Date: 08/17/2009
  • Status: Abandoned Application
First Claim
Patent Images

1. A polarization converting unit arranged on an optical axis of an optical system and configured to convert a polarization state of propagation light passing along an optical-axis direction corresponding to the optical axis, the polarization converting unit comprising:

  • a first optical element comprised of an optical material with an optical rotatory power, which is arranged so as to have a crystal axis coincident or parallel with the optical-axis direction, the first optical element having a plurality of first regions with respective polarization conversion properties to rotate linearly polarized light incident thereto as the propagation light, around the optical-axis direction; and

    a second optical element comprised of an optical material with an optical rotatory power, which is arranged on the exit side of the first optical element and which is arranged so as to have a crystal axis coincident or parallel with the optical-axis direction, the second optical element having a plurality of second regions with respective polarization conversion properties to rotate linearly polarized light incident thereto as the propagation light, around the optical-axis direction,wherein at least two first regions selected from the plurality of first regions have their respective thicknesses different from each other in the optical-axis direction, and wherein the plurality of first regions are arranged so that two first regions with mutually different polarization conversion properties are adjacent to each other,wherein at least two second regions selected from the plurality of second regions have their respective thicknesses different from each other in the optical-axis direction, and wherein the plurality of second regions are arranged so that two second regions with mutually different polarization conversion properties are adjacent to each other, andwherein the first and second optical elements are arranged so that a light beam having passed through one first region of the first optical element is incident to two adjacent second regions of the second optical element, whereby the sum of respective thicknesses in the optical-axis direction of first and second regions through which a first reference axis parallel to the optical-axis direction passes is different from the sum of respective thicknesses in the optical-axis direction of other first and second regions through which a second reference axis parallel to the optical-axis direction and different from the first reference axis passes.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×