An optical fiber rod (30) according to the present invention includes a center region (35), an outer region (31) formed around the center region (35), and an intermediate region (33) formed between the center region (35) and the outer region (31), and satisfies nA>nB>nC where nA is the refractive index of a material A produced by polymerization of a monomer ma, nB is the refractive index of a material B produced by polymerization of a monomer mb, and nC is the refractive index of a material C produced by polymerization of a monomer mc. The center region (35) is made of a material produced by polymerization of a monomer mixture containing the monomer ma, the outer region (31) is made of a material produced by polymerization of a monomer mixture containing the monomer mc, and the intermediate region (33) is made of a material produced by polymerization of a monomer mixture containing the monomer mb. The refractive index decreases in the order: the center region (35)>the intermediate region (33)>the outer region (31).

A method for adjusting an etchability of a first borosilicate glass by heating the first borosilicate glass; combining the first borosilicate glass with a second borosilicate glass to form a composite; and etching the composite with an etchant. A material having a protrusive phase and a recessive phase, where the protrusive phase protrudes from the recessive phase to form a plurality of nanoscale surface features, and where the protrusive phase and the recessive phase have the same composition.

A method for economically mass-producing thin plate-shaped microchannel plate, includes: coating the surface of one or more strands of microfiber with a predetermined diameter with a polysilazane or polysiloxane binder; winding one or more strands of binder-coated microfiber onto a bobbin to form a microfiber bundle; curing the binder while the shape of the microfiber bundle is fixed; and slicing the binder-cured microfiber bundle to manufacture the plate.

A multicore optical fiber (1) includes a plurality of cores (11 to 16) and a cladding (20) surrounding the outer circumferential surfaces of the cores (11 to 16). In the plurality of cores of the multicore optical fiber (1), a skew value (S) between a pair of cores is expressed by a predetermined expression. The multicore optical fiber (1) is bent in a specific bending direction, in which in all of the combinations of the pairs of cores in the plurality of cores, the pair of cores has the maximum absolute value of the skew value found by the expression and the skew value of the pair of cores is a minimum value.

A converter plate includes an array of optical fibers arranged axially parallel to each other. The optical fibers have optical properties selected to convert light from a light-emitting diode entering the optical fibers from one end of the array of optical fibers to light of a different wavelength exiting the fibers from another end of the array of optical fibers. The optical properties of some of the optical fibers differ from the optical properties of others of the optical fibers such that the light exiting the some of the optical fibers has a wavelength different from that of the light exiting the others of the optical fibers. The converter plate is manufactured by providing the optical fibers and combining the optical fibers into a bundle, the optical fibers being arranged axially parallel to each other. The bundle of optical fibers is drawn to attenuate the bundle of fibers into a secondary fiber having a reduced cross section. The secondary fiber is wafered into a converter plate that includes an array of the optical fibers arranged axially parallel to each other.

A method for adjusting an etchability of a first borosilicate glass by heating the first borosilicate glass; combining the first borosilicate glass with a second borosilicate glass to form a composite; and etching the composite with an etchant. A material having a protrusive phase and a recessive phase, where the protrusive phase protrudes from the recessive phase to form a plurality of nanoscale surface features, and where the protrusive phase and the recessive phase have the same composition.

A multicore optical fiber (1) includes a plurality of cores (11 to 16) and a cladding (20) surrounding the outer circumferential surfaces of the cores (11 to 16). In the plurality of cores of the multicore optical fiber (1), a skew value (S) between a pair of cores is expressed by a predetermined expression. The multicore optical fiber (1) is bent in a specific bending direction, in which in all of the combinations of the pairs of cores in the plurality of cores, the pair of cores has the maximum absolute value of the skew value found by the expression and the skew value of the pair of cores is a minimum value

A multi-fiber light guide includes: light guiding fibers, each fiber including an elongated glass core; a glass cladding, the cores being surrounded by the cladding to form a rigid and continuous glass element, the cores having a higher refractive index than the cladding such that light can be guided by a total reflection along the cores, which end in two abutting faces of the glass element such that light can be guided along the cores from one abutting face to the other abutting face; and an ion exchange layer at each of the abutting faces, the glass of the cores and the glass of the cladding including alkali ions, which are at least partly exchanged by alkali ions of a higher atomic number within the ion exchange layer at the abutting faces, the exchanged alkali ions within the ion exchange layer imparting a compressive stress at the abutting faces.

The present invention discloses a fabrication method and use of a 40 mm sized fiber optic image inverter, belonging to the field of manufacturing of fiber optic imaging elements. The light-absorbing glass for preparing the 40 mm sized fiber optic image inverter consists of the following components in molar percentage: SiO.sub.2 60-69.9, Al.sub.2O.sub.3 1.0-10.0, B.sub.2O.sub.3 10.1-15.0, Na.sub.2O 1.0-8.0, K.sub.2O 3.0-10.0, MgO 0.1-1.0, CaO 0.5-5.0, ZnO 0-0.1, TiO.sub.2 0-0.1, ZrO.sub.2 0.1-1.0, Fe.sub.2O.sub.3 3.0-6.5, Co.sub.2O.sub.3 0.1-0.5, V.sub.2O.sub.5 0.51-1.5 and MoO.sub.3 0.1-1.0. The 40 mm sized fiber optic image inverter has the advantages of low crosstalk of stray light, high resolution and high contrast.

A method for economically mass-producing thin plate-shaped microchannel plate, includes: coating the surface of one or more strands of microfiber with a predetermined diameter with a polysilazane or polysiloxane binder; winding one or more strands of binder-coated microfiber onto a bobbin to form a microfiber bundle; curing the binder while the shape of the microfiber bundle is fixed; and slicing the binder-cured microfiber bundle to manufacture the plate.