It is possible to provide a new information recording/reproduction method and a device which can realize a small-size large-capacity memory having a characteristic equivalent to or higher than a hologram memory. The optical information recording/reproduction device includes: recording light generator (51) which generates a recording light (55) in a polarization state having two mutually orthogonal polarization components with a phase difference at an arbitrary polarization base; reproduction light generator (61) which generates a reproduction light (65) in a polarization state having only a single polarization component at a arbitrary polarization basis; recording medium (71) in which optical information is recorded by recording light (55) and the recorded optical information is reproduced by reproduction light; and optical information detector (polarimeter 81) which retrieves information light (72) after being applied to recording medium (71) and detects the light as optical information. Provided is also an optical information recording/reproduction method using the device.

It is possible to provide a new information recording/reproduction method and a device which can realize a small-size large-capacity memory having a characteristic equivalent to or higher than a hologram memory. The optical information recording/reproduction device includes: recording light generator (51) which generates a recording light (55) in a polarization state having two mutually orthogonal polarization components with a phase difference at an arbitrary polarization base; reproduction light generator (61) which generates a reproduction light (65) in a polarization state having only a single polarization component at a arbitrary polarization basis; recording medium (71) in which optical information is recorded by recording light (55) and the recorded optical information is reproduced by reproduction light; and optical information detector (polarimeter 81) which retrieves information light (72) after being applied to recording medium (71) and detects the light as optical information. Provided is also an optical information recording/reproduction method using the device.

A light information recording/reproducing apparatus can improve the optical efficiency of an optical system at the time of reproduction to thereby improve the reproduction transfer rate. An optical element (for example, an optical isolator), which removes a return light beam of a light beam, is arranged such that the light beam passes through the optical element at the time of recording information in an optical information recording medium and such that the light beam does not pass through the optical element at the time of reproducing information from the optical information recording medium.

A light information recording/reproducing apparatus can improve the optical efficiency of an optical system at the time of reproduction to thereby improve the reproduction transfer rate. An optical element (for example, an optical isolator), which removes a return light beam of a light beam, is arranged such that the light beam passes through the optical element at the time of recording information in an optical information recording medium and such that the light beam does not pass through the optical element at the time of reproducing information from the optical information recording medium.

Heterocrystals of metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 are presented, in which the metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 do not largely retain their independent properties. These heterocrystals exhibit electronic and optical changes, which make them attractive for beyond-silicon electronics and optoelectronics. Particularly, these heterocrystals can be re-configured in a manner that allows bit writing and pattern drawing. Embodiments of these heterocrystals, methods of forming these heterocrystals, methods of reconfiguring the heterocrystals, information storage devices, optoelectronic circuits and photonic crystals are presented.

Heterocrystals of metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 are presented, in which the metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 do not largely retain their independent properties. These heterocrystals exhibit electronic and optical changes, which make them attractive for beyond-silicon electronics and optoelectronics. Particularly, these heterocrystals can be re-configured in a manner that allows bit writing and pattern drawing. Embodiments of these heterocrystals, methods of forming these heterocrystals, methods of reconfiguring the heterocrystals, information storage devices, optoelectronic circuits and photonic crystals are presented.

An optical information processing device writes and reads information on an information recording medium having recording layers. The optical information processing device includes: first and second light sources; a light condensing element that condenses light from the first and second light sources on the medium; a first photodetector that receives light reflected by the medium after being emitted from the first light source and generates a first focusing error signal; a second photodetector that receives light reflected by the medium after being emitted from the second light source and generates a second focusing error signal; and a focusing control circuit that controls the light condensing element by using the first focusing error signal in such a manner that the light from the second light source is condensed on each of the recording layers. The second focusing error signal is used to add a correction to the focusing control circuit.

An optical information processing device writes and reads information on an information recording medium having recording layers. The optical information processing device includes: first and second light sources; a light condensing element that condenses light from the first and second light sources on the medium; a first photodetector that receives light reflected by the medium after being emitted from the first light source and generates a first focusing error signal; a second photodetector that receives light reflected by the medium after being emitted from the second light source and generates a second focusing error signal; and a focusing control circuit that controls the light condensing element by using the first focusing error signal in such a manner that the light from the second light source is condensed on each of the recording layers. The second focusing error signal is used to add a correction to the focusing control circuit.

Heterocrystals of metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 are presented, in which the metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 do not largely retain their independent properties. These heterocrystals exhibit electronic and optical changes, which make them attractive for beyond-silicon electronics and optoelectronics. Particularly, these heterocrystals can be re-configured in a manner that allows bit writing and pattern drawing. Embodiments of these heterocrystals, methods of forming these heterocrystals, methods of reconfiguring the heterocrystals, information storage devices, optoelectronic circuits and photonic crystals are presented.

Heterocrystals of metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 are presented, in which the metal dichalcogenides and Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3 or Bi.sub.2Te.sub.3 do not largely retain their independent properties. These heterocrystals exhibit electronic and optical changes, which make them attractive for beyond-silicon electronics and optoelectronics. Particularly, these heterocrystals can be re-configured in a manner that allows bit writing and pattern drawing. Embodiments of these heterocrystals, methods of forming these heterocrystals, methods of reconfiguring the heterocrystals, information storage devices, optoelectronic circuits and photonic crystals are presented.