Patent ID: 8050164
Filing Date: 2011-11-01
Classification: G03H,G11B

Abstract:
1. An optical recording device comprising: a light source that emits coherent light; a spatial light modulator that is formed from a plurality of pixels that are two-dimensionally arrayed, that comprises a signal light region that displays a signal light pattern when generating signal light, and a reference light region that is disposed so as to surround the signal light region and displays a reference light pattern when generating reference light that is coaxial with the signal light, and that modulates and outputs incident light for each pixel in accordance with a display pattern; a correcting optical system that is disposed between the light source and the spatial light modulator and comprises a pair of axicon lenses that correct the light that has been emitted from the light source so as to flatten the light intensity distribution thereof on an irradiated surface of the spatial light modulator; and a light guiding section that guides the light that has been corrected by the correcting optical system to the spatial light modulator, wherein the signal light and the reference light generated by the spatial light modulator are irradiated onto an optical recording medium simultaneously and a hologram is recorded into the optical recording medium; and wherein the pair of axicon lenses that form the correcting optical system are disposed such that conical surfaces thereof face each other and are disposed apart from each other by a distance L that is defined in the following expression: wherein, the distance L is an optical axis component distance of an optical path length between the axicon lenses, φ represents the angle of the apex angle of the axicon lenses, D represents the beam diameter of the light incident on the axicon lenses, and n represents the index of refraction of the axicon lenses, with the index of refraction in air being 1.