A hologram layer (13) is irradiated by light from an optical element (10). The hologram layer (13) is provided with a first hologram (14) that diffracts in a predetermined direction, from among incident light from the optical element (10), X-polarized light in which the polarization component is in a specific direction and emits the light as X-polarized light of a first phase state (P1), and a second hologram (15) that both diffracts in the same direction as the X-polarized light of the first phase state (P1) and moreover at an equal radiation angle, from among incident light from the optical element (10), Y-polarized light in which the polarization component is in a direction orthogonal to that of the X-polarized light and converts it to X-polarized light, and emits the light as X-polarized light of a second phase state (P2) that differs from the first phase state (P1).