An optical fiber includes a glass fiber and a coating resin layer surrounding the outer periphery of the glass fiber. The coating resin layer has a primary resin layer that surrounds the outer periphery of the glass fiber, and a secondary resin layer that surrounds the outer periphery of the primary resin layer. The primary resin layer has a thickness of 7.5 μm or more and 17.5 μm or less. The primary resin layer has a Young's modulus of 0.10 MPa or greater and 0.50 MPa or less at 23° C. The secondary resin layer has a thickness of 5.0 μm or more and 17.5 μm or less. The secondary resin layer has an outer diameter of 165 μm or more and 175 μm or less. The secondary resin layer has a Young's modulus of 1200 MPa or greater and 2800 MPa or less at 23° C.

An optical fiber comprises a glass fiber comprising a core and a cladding, and a coating resin layer covering the outer periphery of the glass fiber, wherein the coating resin layer has a primary resin layer being in contact with the glass fiber and covering the glass fiber and a secondary resin layer covering the outer periphery of the primary resin layer, the secondary resin layer comprises hydrophobic spherical silica particles, and the content of the silica particles is 7% by mass or more and 60% by mass or less based on the total amount of the secondary resin layer, and the absolute value of the surface potential of the optical fiber is 10 mV or more and 60 mV or less.

An optical fiber comprises a glass fiber comprising a core and a cladding, and a coating resin layer covering the outer periphery of the glass fiber, wherein the coating resin layer has a primary resin layer being in contact with the glass fiber and covering the glass fiber and a secondary resin layer covering the outer periphery of the primary resin layer, the secondary resin layer comprises hydrophobic spherical silica particles, and the content of the silica particles is 7% by mass or more and 60% by mass or less based on the total amount of the secondary resin layer, and the absolute value of the surface potential of the optical fiber is 10 mV or more and 60 mV or less.

A perovskite optical element includes a light guiding unit and a luminescent layer. The light guiding unit is configured to conduct light and serves as a resonant cavity. The luminescent layer is a thin film made of perovskite material and clads the light guiding unit. The luminescent layer is configured to be excited by an excitation module to emit light. The light is conducted and output by the light guiding unit. A manufacturing method of a perovskite optical element includes preparing a dip coating solution; dipping a single crystal optical fiber in the dip coating solution for one hour, removing the single crystal optical fiber out of the dip coating solution, and drying the single crystal optical fiber; and placing the single crystal optical fiber into a tube furnace, heating the crystal optical fiber, and introducing synthetic molecules into the tube furnace.

A perovskite optical element includes a light guiding unit and a luminescent layer. The light guiding unit is configured to conduct light and serves as a resonant cavity. The luminescent layer is a thin film made of perovskite material and clads the light guiding unit. The luminescent layer is configured to be excited by an excitation module to emit light. The light is conducted and output by the light guiding unit. A manufacturing method of a perovskite optical element includes preparing a dip coating solution; dipping a single crystal optical fiber in the dip coating solution for one hour, removing the single crystal optical fiber out of the dip coating solution, and drying the single crystal optical fiber; and placing the single crystal optical fiber into a tube furnace, heating the crystal optical fiber, and introducing synthetic molecules into the tube furnace.

Apparatus, systems, and methods that provide coats on a glass optical fiber including of an inner layer and an outer layer. The method includes two steps. First, a conductive polymer coating is applied to the optical fiber as it is being produced. Second, a protective coating is applied to that conductive polymer coating. The conductive polymer coating is applied immediately after the fiber is drawn from preform to fiber.

Apparatus, systems, and methods that provide coats on a glass optical fiber including of an inner layer and an outer layer. The method includes two steps. First, a conductive polymer coating is applied to the optical fiber as it is being produced. Second, a protective coating is applied to that conductive polymer coating. The conductive polymer coating is applied immediately after the fiber is drawn from preform to fiber.

An optical fiber ribbon comprises a plurality of optical fibers arranged in parallel and a connecting resin layer containing a ribbon resin for coating and connecting the plurality of optical fibers, wherein each of the plurality of optical fibers has an outer diameter of 220 .Math.m or less; each of the plurality of optical fibers includes a glass fiber, a primary resin layer, and a colored secondary resin layer; the colored secondary resin layer contains a cured product of a resin composition containing 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and a content of phosphorus in the colored secondary resin layer is 0.03 mass% or more and 0.30 mass% or less, and an amount of a phosphorus-tin complex at the surface of the colored secondary resin layer is 300 ppm or more and 7000 ppm or less.

An optical fiber ribbon comprises a plurality of optical fibers arranged in parallel and a connecting resin layer containing a ribbon resin for coating and connecting the plurality of optical fibers, wherein each of the plurality of optical fibers has an outer diameter of 220 .Math.m or less; each of the plurality of optical fibers includes a glass fiber, a primary resin layer, and a colored secondary resin layer; the colored secondary resin layer contains a cured product of a resin composition containing 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and a content of phosphorus in the colored secondary resin layer is 0.03 mass% or more and 0.30 mass% or less, and an amount of a phosphorus-tin complex at the surface of the colored secondary resin layer is 300 ppm or more and 7000 ppm or less.

A resin composition for secondary coating of an optical fiber is a resin composition comprising: a non-reactive urethane compound having a number average molecular weight of 10000 or more and 40000 or less, a photopolymerizable compound, and a photopolymerization initiator, wherein the content of the non-reactive urethane compound is 0.05 parts by mass or more and 10 parts by mass or less based on the total amount of the resin composition of 100 parts by mass, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 1800 or more and 4500 or less, a diisocyanate, and a compound having active hydrogen.