Patent Number: 7,102,828

Title: Optical element and manufacturing method thereof

Abstract: An optical element and a manufacturing method therefor, an exposure apparatus, and a device manufacturing method that can reduce the effect of intrinsic birefringence under high NA conditions. According to an optical element as one aspect of the present invention, an angle between a [0 0 1] axis of an isometric crystal and an optical axis is less than 10.degree., and preferably 0.degree..

Inventors: Unno; Yasuyuki (Tochigi, JP), Takeuchi; Seiji (Tochigi, JP)

Assignee: Canon Kabushiki Kaisha

International Classification: G02B 3/00 (20060101)

Expiration Date: 9/05/02018