Apparatus and method for recording/reproducing optical information

An optical information recording method for recording information on an optical information recording medium having an information recording layer in which information is recorded through the use of holography, the method comprising:

• the step of generating information light by spatially modulating a phase of light;
• the step of generating recording-specific reference light by spatially modulating a phase of light;
• the recording step in which the information recording layer is irradiated with the information light and the recording-specific reference light so that the information is recorded on the information recording layer in the form of an interference pattern resulting from interference between the information light and the recording-specific reference light;
• and
• wherein, in the step of generating the information light, the phase of the light is spatially modulated in accordance with a phase modulation pattern determined based on the information to be recorded and a phase modulation pattern of the recording-specific reference light.

An optical information reproducing apparatus for reproducing information through the use of holography from an optical information recording medium having an information recording layer in which information is recorded in the form of an interference pattern resulting from interference between information light that is spatially modulated in phase based on information to be recorded, and recording-specific reference light, the apparatus comprising:

• reproduction-specific reference light generating means for generating reproduction-specific reference light;
• a reproducing optical system for irradiating the information recording layer with the reproduction-specific reference light generated by the reproduction-specific reference light generating means, collecting reproduction light that is generated from the information recording layer irradiated with the reproduction-specific reference light, and generating composite light by superimposing the reproduction light on the reproduction-specific reference light;
• and
• detecting means for detecting the composite light generated by the reproducing optical system.

An optical information reproducing method for reproducing information through the use of holography from an optical information recording medium having an information recording layer in which information is recorded in the form of an interference pattern resulting from interference between information light that is spatially modulated in phase based on information to be recorded, and recording-specific reference light, the method comprising:

• the step of generating reproduction-specific reference light;
• the reproducing step in which the information recording layer is irradiated with the reproduction-specific reference light, reproduction light that is generated from the information recording layer irradiated with the reproduction-specific reference light is collected, and composite light is generated by superimposing the reproduction light on the reproduction-specific reference light;
• and
• the step of detecting the composite light.

An optical information recording/reproducing apparatus for recording information on an optical information recording medium having an information recording layer in which information is recorded through the use of holography, and for reproducing the information from the information recording medium, the apparatus comprising:

• information light generating means for generating information light by spatially modulating a phase of light based on information to be recorded;
• recording-specific reference light generating means for generating recording-specific reference light;
• reproduction-specific reference light generating means for generating reproduction-specific reference light;
• a recording/reproducing optical system for irradiating the information recording layer with the information light generated by the information light generating means and the recording-specific reference light generated by the recording-specific reference light generating means when recording information so that the information is recorded in the information recording layer in the form of an interference pattern resulting from interference between the information light and the recording-specific reference light, and irradiating the information recording layer with the reproduction-specific reference light generated by the reproduction-specific reference light generating means, collecting reproduction light that is generated from the information recording layer irradiated with the reproduction-specific reference light, and generating composite light by superimposing the reproduction light on the reproduction-specific reference light when reproducing information;
• and
• detecting means for detecting the composite light generated by the recording/reproducing optical system.

An optical information recording/reproducing method for recording information on an optical information recording medium having an information recording layer in which information is recorded through the use of holography, and for reproducing the information from the information recording medium, the method comprising:

• the step of generating information light by spatially modulating a phase of light based on information to be recorded;
• the step of generating recording-specific reference light;
• the recording step in which the information recording layer is irradiated with the information light and the recording-specific reference light so that the information is recorded on the information recording layer in the form of an interference pattern resulting from interference between the information light and the recording-specific reference light;
• the step of generating reproduction-specific reference light;
• the reproducing step in which the information recording layer is irradiated with the reproduction-specific reference light, reproduction light that is generated from the information recording layer irradiated with the reproduction-specific reference light is collected, and composite light is generated by superimposing the reproduction light on the reproduction-specific reference light;
• and
• the step of detecting the composite light.