Abstract: The present invention provides a two-photon light-emitting compound represented by formula (1), an optical data recording medium comprising a compound represented by formula (1), a two-photon polymerizable composition comprising a polymerizable monomer or polymerizable oligomer and at least a compound represented by formula (1), and a photopolymerization process: X2—(—CR4?CR3—)m—C(?O)—(—CR1?CR2—)n—X1??(1) wherein X1 and X2 may be the same or different and each represent a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group; R1, R2, R3 and R4 each independently represent a hydrogen atom or substituent; some of R1, R2, R3 and R4 may be connected to each other to form at least one ring; and n and m each independently represent an integer of from 1 to 4, with the proviso that when n and m are 2 or more, the plurality of R1,s, R2,s, R3,s, and R4,s each may be the same or different.

Abstract: To provide a composition for a hologram recording material, a hologram recording material and a hologram recording method applicable to a high density optical recording medium, a three-dimensional display, a holographic optical element etc. and capable of attaining a high sensitivity, a high diffraction efficiency, a satisfactory storage property, a low shrinkage rate, a dry process, a multiplex recording property and a high recording density. An unrewritable hologram recording method including a step in which a sensitizing dye absorbs light by an exposure to form an excited state, a chemical reaction step including a color forming reaction involving an electron transfer or an energy transfer from such excited state, and a hologram-forming step by such chemical reaction.

Abstract: A two-photon absorbing optical recording material comprising at least one two-photon absorbing compound and a recording component is provided. Recording is made on it by utilizing the two-photon absorption of the two-photon absorbing compound in the material, and then the material is irradiated with light to thereby detect the difference in the reflectance between the recorded area and the unrecorded area thereof, and the recorded information is thereby reproduced from the material, and also provided are a photosensitive polymer composition and a photon-mode recording method for the material.

Abstract: A two-photon absorbing polymerizable composition contains at least a two-photon absorbing compound, a polymerization initiator and a polymerizable compound, the composition being photopolymerizable upon non-resonant two-photon absorption, wherein the two-photon absorbing compound is a methine dye containing a compound represented by the formula (1): 1

Abstract: An optical information-recording medium which contains a dye having at least two chromophores bonded to each other without any conjugated bond intervening between those chromophores.

Abstract: A non-resonant two-photon absorbing material is provided, comprising a specified compound and exhibiting far stronger non-resonant two-photon absorption and two-photon emission than conventional materials.

Abstract: The present invention provides a two-photon light-emitting compound represented by formula (1), an optical data recording medium capable of recording data with a laser beam comprising a compound represented by formula (1) and a two-photon polymerizable composition photopolymerizable by two-photon absorption comprising a polymerizable monomer or polymerizable oligomer and at least a two-photon absorption material being a compound represented by formula (1):

Abstract: Disclosed is a two-photon absorption composition containing a two-photon absorbing compound having a two-photon absorption cross-section of 102 GM (1 GM=1×10−50 cm4 s molecule−1 photon−1) or more. The high sensitive two-photon absorption composition which can bring about two-photon absorption using a laser having a relatively low power is provided.