Abstract: A vehicle network system is provided with a plurality of star networks, a plurality of devices mounted on a vehicle are connected in a star shape through respective branch lines in each of the star networks, and a trunk line for connecting the plurality of star networks, the branch lines are communication lines for optical communications, and the trunk line is a communication line for electric communication.

Abstract: A taper angle of a self-written optical waveguide to be formed is increased or decreased at a desired position. A range of light (aperture number) condensed by a focusing lens 31 is adjusted by an iris diaphragm 22? in which the hole diameter can be changed from 1 mm to 12 mm. An image of the self-written optical waveguide 51 being fabricated is taken with a CCD camera 70, and image processing of the image is executed in real time by an image processing device 71. The taper angle of the self-written optical waveguide 51 is measured, and the taper angle of the self-written optical waveguide 51 can be desirably increased or decreased by changing the diameter of iris diaphragm 22?.

Abstract: A self-written branched optical waveguide is formed. A laser beam 2 from a laser source (not shown) is focused with a lens 3 onto the face of incidence 10 of an optical fiber 1. The laser beam of an LP11 mode was emitted from the face of emergence 11, and “bimodal” light intensity peaks were arranged in the horizontal direction (1.A). A slide glass 4 coated with a photocurable resin gel 5 was placed horizontally (1.B). A single linear cured material 61 was formed as the LP11-mode laser beam was emitted from the face of emergence 11 of the optical fiber 1 (1.C). A branch portion 62 was then formed at a distance L from the face of emergence 11 of the optical fiber 1, which was followed by the growth of two cylindrical cured materials 63a and 63b. The two cylindrical cured materials 63a and 63b were linear branches, and formed an angle of about four degrees. An optical waveguide 60 thus formed was composed of cured materials 61, 62, 63a, and 63b (1.D).

Abstract: A taper angle of a self-written optical waveguide to be formed is increased or decreased at a desired position. A range of light (aperture number) condensed by a focusing lens 31 is adjusted by an iris diaphragm 22? in which the hole diameter can be changed from 1 mm to 12 mm. An image of the self-written optical waveguide 51 being fabricated is taken with a CCD camera 70, and image processing of the image is executed in real time by an image processing device 71. The taper angle of the self-written optical waveguide 51 is measured, and the taper angle of the self-written optical waveguide 51 can be desirably increased or decreased by changing the diameter of iris diaphragm 22?.

Abstract: [Object] A self-written branched optical waveguide is formed. [Solving Means] A laser beam 2 from a laser source (not shown) is focused with a lens 3 onto the face of incidence 10 of an optical fiber 1. The laser beam of an LP11 mode was emitted from the face of emergence 11, and “bimodal” light intensity peaks were arranged in the horizontal direction (1.A). A slide glass 4 coated with a photocurable resin gel 5 was placed horizontally (1.B). A single linear cured material 61 was formed as the LP11-mode laser beam was emitted from the face of emergence 11 of the optical fiber 1 (1.C). A branch portion 62 was then formed at a distance L from the face of emergence 11 of the optical fiber 1, which was followed by the growth of two cylindrical cured materials 63a and 63b. The two cylindrical cured materials 63a and 63b were linear branches, and formed an angle of about four degrees. An optical waveguide 60 thus formed was composed of cured materials 61, 62, 63a, and 63b (1.D).

Abstract: A vehicle network system is provided with a plurality of star networks, a plurality of devices mounted on a vehicle are connected in a star shape through respective branch lines in each of the star networks, and a trunk line for connecting the plurality of star networks, the branch lines are communication lines for optical communications, and the trunk line is a communication line for electric communication.

Abstract: A transparent vessel is filled with a mixture solution containing a first photo-curable resin of a low refractive index and a second photo-curable resin of a high refractive index different in curing mechanism. When light at a wavelength capable of curing the first photo-curable resin but incapable of curing the second photo-curable resin is applied to the mixture solution through an optical fiber, the first photo-curable resin can be cured in a state in which the second photo-curable resin is enclosed in the cured first photo-curable resin. Because the refractive index increases according to curing, a self-condensing phenomenon can be generated so that an optical path portion is formed. The optical path portion emits leakage light to its surroundings to thereby form an outer circumferential portion. Then, all uncured resins in the mixture solution are cured.

Abstract: In the condition that an acrylic transparent vessel is filled with a curable resin solution capable of being cured by a light, a plastic optical fiber is immersed in the curable resin solution. A laser beam is applied on the curable resin solution through the plastic optical fiber. The curable resin solution is cured gradually by the laser beam applied on the curable resin solution, so that an axial core is formed. Then, the transparent vessel is left at rest for predetermined time, or uncured part of the curable resin solution is removed from the transparent vessel and the transparent vessel is then filled with another curable resin solution. Then, ultraviolet rays are applied on the transparent vessel from the outside of the transparent vessel to cure the residual uncured part of the curable resin solution.

Abstract: Transparent parallel planar plates which are members for retaining an optical waveguide are provided erectly in an optical path of light in a transparent vessel in advance. An optical fiber is fixed into the transparent vessel while the optical fiber penetrates the transparent vessel, and an optical sensor is also disposed adjustably. Next, a first photo-curable resin solution is injected into the transparent vessel, and light with a predetermined wavelength for curing is emitted from the optical fiber so that the optical waveguide is self-formed by polymerization reaction. Because the parallel planar plates are transparent, the optical waveguide is formed so as to be extended again from the emission ports of the parallel planar plates. Finally, the optical waveguide is formed so as to reach a bottom surface of the transparent vessel.

Abstract: Interference filters which are optical components are erected in advance on optical paths in a transparent container, and the transparent container is filled with a photo-curable resin solution. Further, a jig is prepared for manufacturing an optical waveguide device. The jig includes a housing, and holes. On this occasion, positions of the holes are set such that light input through the hole reaches the holes via the interference filters. Optical fibers are fitted into the holes of the housing and the housing is mounted on the transparent container. Next, light at a predetermined wavelength is guided into the optical fibers so that optical waveguides are formed in the photo-curable resin solution. Next, the photo-curable resin solution is exchanged for a low-refractive-index photo-curable resin solution and then the low-refractive-index photo-curable resin solution is solidified wholly by ultraviolet light. Finally, for example, an optical fiber, a light-receiving element, etc. are provided.

Abstract: Into a mixture solution 2 of a high-refractive-index photo-curable resin A and a low-refractive-index photo-curable resin B, light capable of curing only the resin A is led through an optical fiber 1 so that a cured resin 211 of the resin A having a diameter substantially equal to the diameter of a core portion of the optical fiber is formed so as to extend from a tip of the optical fiber. Then, the residual mixture solution 2 is cured. In this manner, a module having the previously cured high-refractive-index resin 211 as an optical waveguide can be formed easily. On this occasion, the mixed state of the mixture solution 2 can be kept good enough to facilitate the formation of the high-refractive-index resin 211 when the solubility parameter ?A of the high-refractive-index photo-curable resin A and the solubility parameter ?B and volume fraction ?B of the low-refractive-index photo-curable resin B satisfy the following expression (4). |?A??B|<?7.5?B+6.

Abstract: In the condition that an acrylic transparent vessel is filled with a curable resin solution capable of being cured by a light, a plastic optical fiber is immersed in the curable resin solution. A laser beam is applied on the curable resin solution through the plastic optical fiber. The curable resin solution is cured gradually by the laser beam applied on the curable resin solution, so that an axial core is formed. Then, the transparent vessel is left at rest for predetermined time, or uncured part of the curable resin solution is removed from the transparent vessel and the transparent vessel is then filled with another curable resin solution. Then, ultraviolet rays are applied on the transparent vessel from the outside of the transparent vessel to cure the residual uncured part of the curable resin solution.

Abstract: Interference filters which are optical components are erected in advance on optical paths in a transparent container, and the transparent container is filled with a photo-curable resin solution. Further, a jig is prepared for manufacturing an optical waveguide device. The jig includes a housing, and holes. On this occasion, positions of the holes are set such that light input through the hole reaches the holes via the interference filters. Optical fibers are fitted into the holes of the housing and the housing is mounted on the transparent container. Next, light at a predetermined wavelength is guided into the optical fibers so that optical waveguides are formed in the photo-curable resin solution. Next, the photo-curable resin solution is exchanged for a low-refractive-index photo-curable resin solution and then the low-refractive-index photo-curable resin solution is solidified wholly by ultraviolet light. Finally, for example, an optical fiber, a light-receiving element, etc. are provided.

Abstract: An optical fiber, a mixture solution of the photosetting resins polymerizing in two different polymerization types, and a transparent container are prepared. The photosetting resins are not copolymerized, and have different activation wavelengths of the photopolymerization initiators for hardening. Employing a combination in which the activation wavelength of a photopolymerization initiator for a photosetting resin with higher refractive index after hardening is longer than the activation wavelength of a photopolymerization initiator for a photosetting resin with lower refractive index after hardening, a core portion can be only formed by hardening the photosetting resin with higher refractive index due to a difference between two wavelengths. Thereafter, a clad portion can be formed by hardening two kinds of photosetting resins, whereby an optical transmission device can be manufactured.

Abstract: A transparent vessel is filled with a mixture solution containing a first photo-curable resin of a low refractive index and a second photo-curable resin of a high refractive index different in curing mechanism. When light at a wavelength capable of curing the first photo-curable resin but incapable of curing the second photo-curable resin is applied to the mixture solution through an optical fiber, the first photo-curable resin can be cured in a state in which the second photo-curable resin is enclosed in the cured first photo-curable resin. Because the refractive index increases according to curing, a self-condensing phenomenon can be generated so that an optical path portion is formed. The optical path portion emits leakage light to its surroundings to thereby form an outer circumferential portion. Then, all uncured resins in the mixture solution are cured.

Abstract: A method of fabricating an optical waveguide structure includes the step of introducing light into a photo-curable liquid resin. The liquid resin can be a mixture of two types of photo-curable liquid resins having different curing initiation wavelengths and different refractive indexes. The method can include dipping one end of a fiber into the liquid mixture. Light having a wavelength &lgr;1 can be radiated from the tip end of the optical fiber in order to cure one of the photo-curable liquid resins thereby forming a waveguide. Light having a different wavelength &lgr;2 can be radiated from an area surrounding the waveguide so as to cure the liquid mixture and form a cladding portion around the waveguide.

Abstract: Into a mixture solution 2 of a high-refractive-index photo-curable resin A and a low-refractive-index photo-curable resin B, light capable of curing only the resin A is led through an optical fiber 1 so that a cured resin 211 of the resin A having a diameter substantially equal to the diameter of a core portion of the optical fiber is formed so as to extend from a tip of the optical fiber. Then, the residual mixture solution 2 is cured. In this manner, a module having the previously cured high-refractive-index resin 211 as an optical waveguide can be formed easily. On this occasion, the mixed state of the mixture solution 2 can be kept good enough to facilitate the formation of the high-refractive-index resin 211 when the solubility parameter &dgr;A of the high-refractive-index photo-curable resin A and the solubility parameter &dgr;B and volume fraction &PHgr;B of the low-refractive-index photo-curable resin B satisfy the following expression (4).

Abstract: Interference filters which are optical components are erected in advance on optical paths in a transparent container, and the transparent container is filled with a photo-curable resin solution. Further, a jig is prepared for manufacturing an optical waveguide device. The jig includes a housing, and holes. On this occasion, positions of the holes are set such that light input through the hole reaches the holes via the interference filters. Optical fibers are fitted into the holes of the housing and the housing is mounted on the transparent container. Next, light at a predetermined wavelength is guided into the optical fibers so that optical waveguides are formed in the photo-curable resin solution. Next, the photo-curable resin solution is exchanged for a low-refractive-index photo-curable resin solution and then the low-refractive-index photo-curable resin solution is solidified wholly by ultraviolet light. Finally, for example, an optical fiber, a light-receiving element, etc. are provided.

Abstract: Transparent parallel planar plates which are members for retaining an optical waveguide are provided erectly in an optical path of light in a transparent vessel in advance. An optical fiber is fixed into the transparent vessel while the optical fiber penetrates the transparent vessel, and an optical sensor is also disposed adjustably. Next, a first photo-curable resin solution is injected into the transparent vessel, and light with a predetermined wavelength for curing is emitted from the optical fiber so that the optical waveguide is self-formed by polymerization reaction. Because the parallel planar plates are transparent, the optical waveguide is formed so as to be extended again from the emission ports of the parallel planar plates. Finally, the optical waveguide is formed so as to reach a bottom surface of the transparent vessel.

Abstract: An optical fiber, a mixture solution of the photosetting resins polymerizing in two different polymerization types, and a transparent container are prepared. The photosetting resins are not copolymerized, and have different activation wavelengths of the photopolymerization initiators for hardening. Employing a combination in which the activation wavelength of a photopolymerization initiator for a photosetting resin with higher refractive index after hardening is longer than the activation wavelength of a photopolymerization initiator for a photosetting resin with lower refractive index after hardening, a core portion can be only formed by hardening the photosetting resin with higher refractive index due to a difference between two wavelengths. Thereafter, a clad portion can be formed by hardening two kinds of photosetting resins, where by an optical transmission device can be manufactured.