Provided is an optical medium reproducing apparatus including: a detection unit that divides a luminous flux into a plurality of regions including a first region and a second region which are different in a position in a radial direction and/or a tangential direction, and combines a plurality of detection signals in correspondence with the amount of light that is incident to each of the plurality of regions with combination patterns which are selected to form signals of a plurality of channels; a multi-input equalizer unit that includes a plurality of equalizer units to which the signals of the plurality of channels are respectively supplied, computes outputs of the plurality of equalizer units, and outputs the resultant value as an equalization signal; and a binarization unit that performs binarization processing with respect to the equalization signal to obtain binary data. An addition signal channel including a constant multiplication of detection signals of the first region and the second region is included in at least one of the combination patterns.

An information recording/playback device includes a recording pulse generation unit generates a recording pulse based on a multi-value modulation data, and a data recording unit records the mark on the recording medium based on the recording pulse. The data recording unit executes recording processing of setting sizes of all of marks to be recorded on the recording medium to a size equal to or smaller than a spot size at a half level of a maximum value of a two-dimensional light intensity distribution of a beam spot, and executes data recording processing of forming recording regions in modes having different densities of recording marks according to the levels of the multi-value modulation data.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

In an information recording/playback device adopting multi-value recording, a configuration to limit the size of marks to be recorded on a recording medium only to a predetermined size equal to or smaller than a beam spot size to enable prevention and reduction of crosstalk and crosswrite is implemented. A recording pulse generation unit configured to generate a recording pulse based on a multi-value modulation data, and a data recording unit configured to record the mark on the recording medium on the basis of the recording pulse are included. The data recording unit executes recording processing of setting sizes of all of marks to be recorded on the recording medium to a size equal to or smaller than a spot size at a half (½) level of a maximum value (Pmax) of a two-dimensional light intensity distribution (power profile) of a beam spot, and executes data recording processing of forming recording regions in modes having different densities of recording marks according to the levels of the multi-value modulation data.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.

An optical memory includes a support and nanoparticles, each of which changes between a crystal phase and an amorphous phase when irradiated with light. The nanoparticles are supported by the support and spaced apart from each other in one or both of an in-plane direction of a face of the support and a direction normal to the face of the support.

Long term optical memory includes a storage medium composed from an array of silicon nanoridges positioned onto the fused silica glass. The array has first and second polarization contrast corresponding to different phase of silicon. The first polarization contrast results from amorphous phase of silicon and the second polarization contrast results from crystalline phase of silicon. The first and second polarization states are spatially distributed over plurality of localized data areas of the storage medium.