PROJECTION OPTICAL SYSTEM, EXPOSURE DEVICE, AND EXPOSURE METHOD

摘要

A projection optical system having excellent optical performance without being substantially influenced by birefringence even when a crystalline material exhibiting a natural birefringence such as fluorite is used. The projection optical system comprises a plurality of crystalline transmissive members formed of a crystalline material and a non-crystalline transmissive member formed of a non-crystalline material. An image of a first surface R is formed on a second surface W. The crystalline transmissive members each comprise a first group of light transmissive members L22 so formed that the axis of crystal [100] substantially agrees with the optical axis and a second group of crystalline transmissive members L23 each of which is so formed that the axis of crystal [100] substantially agrees with the optical axis, and that has a positional relation in which it is relatively rotated by approximately 45° around the optical axis with respect to the first group of the light transmissive members. The non-crystalline transmissive member L19 has a predetermined birefringence distribution for compensating the influence of the birefringence of the crystalline transmissive members.