OPTICAL INTEGRATOR, ILLUMINATION OPTICAL DEVICE, EXPOSURE DEVICE, AND DEVICE MANUFACTURING METHOD

摘要

Provided is an optical integrator capable of suppressing the optical quantity loss upon deformed illumination of an illumination optical device and having a sufficient durability against an ultraviolet range of short wavelength. The optical integrator is a wavefront division type and includes a single optical member (4) made of a fluoride crystalline material. A plurality of refraction planes (4a) are formed on the incident side of the single optical member in such a manner that they are adjacent to one another for giving a refraction function to the incident light. A plurality of deflection planes (4b) are formed on the outgoing side of the single optical member in such a manner that they are arranged to correspond to the plurality of refraction planes for changing the light advance direction.