Two-photon-absorbing recording medium, two-photon-absorbing recording/reproducing method, and two-photon-absorbing recording/reproducing apparatus

Abstract

Provided are a two-photon-absorbing recording medium allowing recording and reproduction of a large volume of information, a two-photon-absorbing recording / reproducing method by using the same, and a two-photon-absorbing recording / reproducing apparatus. The two-photon-absorbing recording medium for recording information by simultaneous two-photon absorption is a medium comprising an alternate laminate structure comprising: a thin-film recording layer of a recording material wherein change in the absorption or emission spectrum thereof is generated by two-photon absorption induced by a light irradiated as recording light; and a thin-film non-recording layer, wherein the recording material forming the recording layer comprising at least one of each of (1) a two-photon-absorbing colorant and (2) a material wherein change in the absorption or emission spectrum thereof is generated in a photochemical reaction caused by an excited state of the two-photon-absorbing colorant generated by two-photon absorption of the two-photon-absorbing colorant.

Description

technical field [0001] The present invention relates to a two-photon absorption recording medium using a two-photon absorption colorant, a two-photon absorption recording / reproduction method, and a two-photon absorption recording / reproduction apparatus. Background technique [0002] Two-photon absorption is a phenomenon whereby a compound is excited by simultaneous absorption of two photons, and absorption of two photons by a compound in an energy range in which there is no (linear) absorption band is called non-resonant two-photon absorption. In the following description, unless specifically stated otherwise, two-photon absorption is non-resonant two-photon absorption. [0003] The efficiency of off-resonant two-photon absorption is proportional to the square of the applied optical field (square-law property of two-photon absorption). Therefore, when laser light is irradiated on a two-dimensional plane, two-photon absorption occurs only in the center of the laser spot wher...

AI Technical Summary

Problems solved by technology

However, these monolithic optical recording media have lower resolution in the depth direction and it is difficult to increase the recording density in this direction due to the interlayer crosstalk generated

It is not yet possible to read information on monolithic optical recording media by reflection (see for example, T.Shiono et al., Jpn.J.Appl.Phys., 2005, 44, 3559-3563).

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