Method and apparatus for light beam scanning using a hologram

摘要

A method for constructing a hologram on a transparent disk which includes two steps. First, irradiating a reference wave light beam having a diverging spherical wave front from a first point light source located at a predetermined distance on a center axis of the transparent disk. Second, irradiating an object wave light beam having a diverging spherical wave front from a second point light source located at a predetermined distance on a normal line away from a predetermined distance from the center axis. The result is interference between the reference wave light beam irradiated by the first point light source and the object wave light beam irradiated by the second point light source on the transparent disk and the formation of interference fringes having an extreme value of a spatial frequency as a hologram in one embodiment, a reconstruction beam is irradiated to the position, or in the vicinity of the extreme value.