Abstract: A near field optical disc and a near field optical disc reading apparatus are provided. The near field optical disc has at least one light source and a near field optical pick-up head, and the near field optical disc includes a light guiding substance, a first reflection layer and a second reflection layer. The light guiding substance has a first surface, a second surface opposite thereto and at least one light entrance window. Light emitted from the light source enters the light guiding substance through the light entrance window. The second reflection layer is disposed on the second surface. The first reflection layer is disposed on the first surface and has a plurality of light pervious holes. A part of the light is transmitted through the light pervious holes and picked up by the near field optical pick-up head.

Abstract: A collinear volume holographic optical storage system records a plurality pages of holographic data on the storage material, where the intensity distribution of the saved recorded holographic data of each page is in a “+” format. It is possible to incur the inter-page cross talk between two adjacent pages of holographic data along the storage track or between two adjacent storage tracks. An rotation angle between the direction of the distribution of the volume grating and the direction of the storage track can be used to increase the descendent of data storage intensity along storage track, so the effect of the inter-page cross talk is decreased; or the distance between reading centers of two pages of holographic data is shorten to increase the storage density of the storage material.

Abstract: A spatial light modulator applied to the collinear volume holographic storage system uses a hollow phase modulator to modulate the surrounding portion of an incident light to be a reference light, and the center portion of the incident light is modulated by an amplitude modulator to be a signal light. Thus, the spatial light modulator can enhance the convergence of the point spread function of the system.

Abstract: A spatial light modulator applied to the collinear volume holographic storage system uses a hollow phase modulator to modulate the surrounding portion of an incident light to be a reference light, and the center portion of the incident light is modulated by a strength modulator to be a signal light. Thus, the spatial light modulator can enhance the convergence of the point spread function of the system.