According to the present invention, as a monomer which is unlikely to be crystallized in a curable composition for manufacturing an optical member and which enables manufacture of a cured product having a high level of moisture-heat resistance, a compound represented by General Formula (A) is provided. ##STR00001## In the formula, Ar.sup.11 and Ar.sup.12 each independently represent an aryl group or a heteroaryl group; X.sup.1, Y.sup.1, X.sup.2, Y.sup.2, Z.sup.1, and Z.sup.2 each independently represent a nitrogen atom or a carbon atom, or the like; Ar.sup.13 and Ar.sup.14 each independently represent an arylene group or a heteroarylene group, where at least one of Ar.sup.13 or Ar.sup.14 is a group other than a phenylene group; R.sup.3 to R.sup.6 each independently represent a substituent, q and r each independently are an integer of 0 to 4, and v and w each independently are an integer of 0 or more; L.sup.1 and L.sup.2 each independently represent a single bond, an oxygen atom, an ester bond, or the like; R.sup.11 and R.sup.12 each independently represent a divalent linking group containing a branched alkylene group; and R.sup.21 and R.sup.22 each independently represent a hydrogen atom or a methyl group.

The purpose of the present invention is to provide a photopolymerizable composition which can act as a photopolymerization sensitizer that is active against light having a wavelength falling within a wavelength range of from 300 to 500 nm, and which has such a property that coloring of a cured product produced by polymerizing a photopolymerizable composition containing the photopolymerization sensitizer is less. A photopolymerization sensitizer composition characterized by comprising a photopolymerization sensitizer containing an alkoxyanthracene compound represented by the formula (1) and a singlet oxygen quencher; and a photopolymerizable composition containing the photopolymerization sensitizer composition: ##STR00001##
in the formula (1), n represents an integer of 1 or 2; R represents a C.sub.1-12 alkyl group; and X represents a hydrogen atom or a C.sub.1-8 alkyl group.

An optical laminate or a reddening-resistant layer. The optical laminate does not cause a reddening phenomenon even when driven or maintained under extremely harsh conditions (e.g., very high temperature conditions), or a reddening-resistant layer applied thereto.

The disclosure provides recording materials including mono- or poly-phenyl-core derivatized monomers and polymers for use in volume Bragg gratings, including, but not limited to, volume Bragg gratings for holography applications. Several structures are disclosed for mono- or poly-phenyl-core derivatized monomers and polymers for use in Bragg gratings applications, leading to materials with higher refractive index, low birefringence, and high transparency. The disclosed mono- or poly-phenyl-core derivatized monomers and polymers thereof can be used in any volume Bragg gratings materials, including two-stage polymer materials where a matrix is cured in a first step, and then the volume Bragg grating is written by way of a second curing step of a monomer.

A UV-curable and recyclable thermoset shape memory polymer is provided. The polymer includes a vitrimer-based monomer and a photoinitiator. The vitrimer-based monomer includes a first unit rendering a high chain stiffness upon polymerization of the monomer, and a second photopolymerizable unit for photopolymerization of the monomer under a UV irradiation. The polymer has high strength, high stiffness, high recovery stress, high energy storage, reasonable recycling efficiency, and is printable using SLA with high resolution.

The optical fibers disclosed is a single mode optical fiber comprising a core region and a cladding region surrounding and directly adjacent to the core region. The core region can have a radius r.sub.1 in a range from 3 μm to 7 μm and a relative refractive index profile Δ.sub.1 having a maximum relative refractive index Δ.sub.1max in the range from 0.25% to 0.50%. The cladding region can include a first outer cladding region and a second outer cladding region surrounding and directly adjacent to the first outer cladding region. The first outer cladding region can have a radius r.sub.4a. The second outer cladding region can have a radius r.sub.4b less than or equal to 45 μm and comprising silica based glass doped with titania.

Additive manufacturing compositions include low-absorbing particles or non-absorbing particles that have an absorbance for wavelengths of 300 nm to 700 nm that is equal to or greater than 0 Au and is less 1.0 Au, such as 0.001 Au≤absorbance≤0.7 Au. Slurries including such particles and an uranium-containing particle and that are used in additive manufacturing processes have an increased penetration depth for curative radiation. Removal of low-absorbing particles or non-absorbing particles during post-processing of as-manufactured products results in pores that create porosity in the as-manufactured product that provide a volume accommodating fission gases and/or can enhance wicking of certain heat pipe coolant liquids. Low-absorbing particles or non-absorbing particles can be functionalized for improved properties, for example, with fissionable material for improved ceramic yields, with burnable poisons or stabilizers for increased homogeneity, with stabilizers for localized delivery of the stabilizer, or with combinations thereof.

An optical element containing a cured product of a resin composition containing a compound represented by the formula (1):

##STR00001## wherein X.sub.1 denotes a substituted phenyl group with at least one trifluoromethyl group and is optionally substituted with a hydrogen atom, C1-C4 alkyl group, and/or C1-C3 alkylene group, X.sub.2 denotes a substituted or unsubstituted phenyl group, A denotes at least one of a substituted or unsubstituted phenyl group and a substituted or unsubstituted biphenyl group, the substituted phenyl group of X.sub.2 and the substituted phenyl group and the substituted biphenyl group of A have at least one of a hydrogen atom, trifluoromethyl group, C1-C4 alkyl group, and C1-C3 alkylene group, and P.sub.1, P.sub.2, and P.sub.3 denote an acryloyloxy group or a methacryloyloxy group, a, b, and c denote an integer of 0 to 2, and a+b+c denotes an integer of 1 to 3.

Additive manufacturing compositions include low-absorbing particles or non-absorbing particles that have an absorbance for wavelengths of 300 nm to 700 nm that is equal to or greater than 0 Au and is less 1.0 Au, such as 0.001 Au≤absorbance≤0.7 Au. Slurries including such particles and an uranium-containing particle and that are used in additive manufacturing processes have an increased penetration depth for curative radiation. Removal of low-absorbing particles or non-absorbing particles during post-processing of as-manufactured products results in pores that create porosity in the as-manufactured product that provide a volume accommodating fission gases and/or can enhance wicking of certain heat pipe coolant liquids. Low-absorbing particles or non-absorbing particles can be functionalized for improved properties, for example, with fissionable material for improved ceramic yields, with burnable poisons or stabilizers for increased homogeneity, with stabilizers for localized delivery of the stabilizer, or with combinations thereof.

A polymerization initiator includes a transition metal compound, a nitrogen-containing compound, and a sulfonyl group-containing compound.