Hologram and exposure apparatus

An exposure apparatus comprising:

• an illumination optical system configured to illuminate a reticle with a light source, the illumination optical system including a hologram which forms a light intensity distribution on a predetermined plane by using incident light;
• and
• a projection optical system configured to project a pattern of the reticle onto a substrate,
• wherein the hologram comprises:
• a plurality of cells configured to control both a phase of a first polarized light component in a first polarization direction of the incident light and a phase of a second polarized light component in a second polarization direction perpendicular to the first polarization direction, to form a phase difference distribution between phase distributions for the first and second polarized light components, and
• wherein the plurality of cells are designed so that a number of phase difference levels of the phase difference distribution is less than a number of phase levels of the phase distribution of the first polarized light component.