Aperture and optical device using the same

摘要

An aperture used in an optical device includes a first light-transmitting region which transmits light emitted from a light source which is provided in the optical device, and a second light-transmitting region which is provided in the periphery of the first light-transmitting region and provides light passing therethrough with a phase difference of 180° with respect to light passing through the first light-transmitting region. Thus, improvement in a function which is required for the optical device can be achieved.