Abstract: An optical circuit assembly including a first substrate having a plurality of first recesses, a plurality of optical components mounted in the first recesses of the first substrate, respectively, a first cushion sheet attached to the first substrate and having a plurality of openings at positions respectively corresponding to the positions of the first recesses, and a plurality of optical fibers connected to the optical components and formed to be arranged on the first cushion sheet. The first recesses have shapes corresponding to the shapes of the optical components. The optical circuit assembly further includes a second substrate having a plurality of second recesses at positions respectively corresponding to the positions of the first recesses, and a second cushion sheet attached to the second substrate so as to cover the second recesses. The second recesses also have shapes corresponding to the shapes of the optical components.

Abstract: An optical module including a substrate, a plurality of optical components mounted on the substrate, and a plurality of first optical fibers connected to the optical components. The optical module further includes a fiber sheet including a first resin sheet having an adhesive layer on one side, a plurality of second optical fibers wired on the adhesive layer of the first resin sheet, and a second resin sheet attached to the first resin sheet so that the second optical fibers are sandwiched between the first and second resin sheets. The second optical fibers of the fiber sheet project from between the first and second resin sheets and are connected to the first optical fibers by fusion splicing.

Abstract: A optical fiber reel module including a reel having a continuous outer circumference and an optical fiber wound around the reel. The optical fiber reel module further includes an adjustable diameter between a first length and a second length and after an optical fiber is wound around the reel.

Abstract: A rare-earth doped optical fiber module including a resin reel having elasticity and a rare-earth doped optical fiber wound around the resin reel. The rare-earth doped optical fiber module further includes a single-mode optical fiber spliced to the rare-earth doped optical fiber and wound around the resin reel. The resin reel is formed of silicone rubber, fluororubber, or soft PVC.

Abstract: A fiber sheet including a first resin sheet having an adhesive layer on one side, first and second optical fibers wired on the adhesive layer of the first resin sheet so as to cross each other, and a plurality of spacers scattered on the adhesive layer of the first resin sheet. The fiber sheet further includes a second resin sheet attached to the first resin sheet so that the first and second optical fibers and the spacers are sandwiched between the first and second resin sheets. Preferably, each spacer is a spherical spacer.

Abstract: An optical fiber splicer for splicing a plurality of first optical fibers arranged in spaced relationship with each other and a plurality of second optical fibers arranged in opposed relationship with the first optical fibers. The optical fiber splicer includes an XY table movable in XY directions orthogonal to each other, a tray mounted on the XY table, and first and second clamps for respectively clamping a selected one of the first optical fibers and a selected one of the second optical fibers to be spliced to the selected first optical fiber. The optical fiber splicer further includes first and second electrodes extending vertically and aligned with each other, first and second cameras located so as to interpose the first electrode, and an image processing unit for processing images picked up by the first and second cameras.

Abstract: A rare-earth doped optical fiber module including a resin reel having elasticity and a rare-earth doped optical fiber wound around the resin reel. The rare-earth doped optical fiber module further includes a single-mode optical fiber spliced to the rare-earth doped optical fiber and wound around the resin reel. The resin reel is formed of silicone rubber, fluororubber, or soft PVC.

Abstract: An optical fiber splicer for splicing a plurality of first optical fibers arranged in spaced relationship with each other and a plurality of second optical fibers arranged in opposed relationship with the first optical fibers. The optical fiber splicer includes an XY table movable in XY directions orthogonal to each other, a tray mounted on the XY table, and first and second clamps for respectively clamping a selected one of the first optical fibers and a selected one of the second optical fibers to be spliced to the selected first optical fiber. The optical fiber splicer further includes first and second electrodes extending vertically and aligned with each other, first and second cameras located so as to interpose the first electrode, and an image processing unit for processing images picked up by the first and second cameras.

Abstract: An optical module including a substrate, a plurality of optical components mounted on the substrate, and a plurality of first optical fibers connected to the optical components. The optical module further includes a fiber sheet including a first resin sheet having an adhesive layer on one side, a plurality of second optical fibers wired on the adhesive layer of the first resin sheet, and a second resin sheet attached to the first resin sheet so that the second optical fibers are sandwiched between the first and second resin sheets. The second optical fibers of the fiber sheet project from between the first and second resin sheets and are connected to the first optical fibers by fusion splicing.

Abstract: A fiber sheet including a first resin sheet having an adhesive layer on one side, first and second optical fibers wired on the adhesive layer of the first resin sheet so as to cross each other, and a plurality of spacers scattered on the adhesive layer of the first resin sheet. The fiber sheet further includes a second resin sheet attached to the first resin sheet so that the first and second optical fibers and the spacers are sandwiched between the first and second resin sheets. Preferably, each spacer is a spherical spacer.

Abstract: An optical circuit assembly including a first substrate having a plurality of first recesses, a plurality of optical components mounted in the first recesses of the first substrate, respectively, a first cushion sheet attached to the first substrate and having a plurality of openings at positions respectively corresponding to the positions of the first recesses, and a plurality of optical fibers connected to the optical components and formed to be arranged on the first cushion sheet. The first recesses have shapes corresponding to the shapes of the optical components. The optical circuit assembly further includes a second substrate having a plurality of second recesses at positions respectively corresponding to the positions of the first recesses, and a second cushion sheet attached to the second substrate so as to cover the second recesses. The second recesses also have shapes corresponding to the shapes of the optical components.

Abstract: There are disclosed an optical fiber splicing mechanism, an optical fiber splicing structure, and an optical fiber splicing method which are each capable of minimizing the size of an optical-fiber junction and the cost of splicing optical fibers as well as connecting the optical fibers reliably by a simple splicing process. Ends of two ferrules each having an optical fiber fitted therein are held in contact with each other, and the contact portions of the two ferrules are sheathed with a split sleeve. Further, the outside of the split sleeve is sheathed with a heat shrinking tube. Then, heat is applied to the heat shrinking tube to cause the same to shrink. The heat shrinking tube constricts the split sleeve by its shrinkage force, whereby the ferrules are fixed.

Abstract: A light amplification coupler includes a glass pipe, a first optical fiber having, at one end thereof, an input port to which signal light is inputted and having an output port at the other end thereof, the first optical fiber having an intermediate portion inserted in the glass pipe, a second optical fiber having one end portion adapted to receive pump light, the second optical fiber being inserted in the glass pipe and fused to the first optical fiber, and a third optical fiber having an output port at one end thereof, the other end of the third optical fiber being inserted in the glass pipe from the output port side of the first optical fiber and fused to the first and second optical fibers.

Abstract: A first process of the invention comprises forming two constricted portions (28) at a quartz reaction tube (4), charging a solution of a compound of a rare earth element as a solution into the section between the constricted portions (28) for doping. By this, the doping concentration becomes uniform along the length of an optical fiber preform (30) with defects being rarely produced. This process does not involve any complicated operation. A second process of the invention comprises impregnating a solution in the form of a mist in a soot-like core glass (26) by which it becomes possible to control the doping concentration in high accuracy. A third process of the invention comprises impregnating a solution while controlling the concentration in response to a quantity of a transmitted laser beam through a soot-like core glass (26), by which the doping concentration is ensured independently of the density of the soot-like core glass.

Abstract: A method of manufacturing an optical module for wavelength-division multiplex optical transmission, which module comprises a first optical fiber having a first port at its one end and a second and a third optical fiber fused to the first optical fiber at its side face such that the first optical fiber is positioned in the center between the second and third optical fibers. The manufacturing method comprises a first step of regulating the aspect ratio at the fused portion while heating the fused portion and elongating the fused portion at zero speed or a very low speed and a second step of regulating the coupling length of the fused portion while elongating the fused portion at a higher speed than in the aspect ratio regulating step under the conditions of the heating temperature of the fused portion lowered and the aspect ratio kept unchanged.

Abstract: A star coupler for interconnecting optical fibers to distribute optical signals. The method for fabricating the star coupler comprises the steps of preparing a tubular member and first and second groups of optical fibers having bare fiber portions extending from the ends. The bared fiber portions of the first and second groups of optical fibers are inserted into the tubular member, in the opposite directions, in an end-to-end abutting relationship. The contacting ends of the bared fiber portions are then molten and fused together. The fused fiber portions are finally stretched together with the tubular member. It is possible to preheat the tubular member at a relatively low temperature so that the tubular member shrinks relative to the bared fiber portions to retain the latter. The obtained star coupler comprises first and second groups of optical fibers inserted into a tubular member in an end-to-end abutment relationship, with the ends joined together.

Abstract: Disclosed is a polarization-splitting fiber coupler capable of stably executing a polarization separation/coupling and a method of stably manufacturing the polarization-splitting fiber coupler at a low cost. The method comprises the steps of (1) arranging a plurality of non-polarization fibers in parallel so that the side surfaces thereof come into contact to each other; (2) heating and fusing a portion of the arranged non-polarization fibers by controlling a heating temperature and a heating time so that the cross section of the fused portion thereof has an aspect ratio of 1.85-1.95; (3) thereafter, forming a fused/drawn portion by drawing the fused portion while keeping the aspect ratio after lowering the heating temperature; and (4) connecting polarization-maintaining fibers to the respective ends of the fused/drawn portion, respectively. Further, a portion of the connected polarization-maintaining fiber is heated and drawn to a taper-shape to provide the heated-fused portion with a polarizer function.

Abstract: Disclosed are a planar wave guide type optical amplifier for amplifying a light signal passing through an optical fiber, a method of manufacturing the above light amplifier, and a laser oscillator using the light amplifier, The planar wave guide type optical amplifier comprises a first core formed to a bar shaped on a substrate and a light amplifying region composed of a part of the first core, having a configuration extending to the longitudinal direction of the first core, and doped with a rare earth element. The method of manufacturing the planar wave guide type optical amplifier comprises the steps of (1) forming a bar-shaped core on a plane substrate, (2) forming a groove to the core which extends to the longitudinal direction thereof, (3) filling the groove with a filler doped with a rare earth element and (4) solidifying the filler.

Abstract: A method for fabricating a waveguide type optical device is disclosed, through which a core and a reference plane are obtained at the same time by etching a core layer using a thin layer of a predetermined shape formed on the core layer as a mask. In this waveguide type optical device, the core is easily coupled with an optical element such as an optical fiber by means of the reference plane.

Abstract: A first process of the invention comprises forming two constricted portions (28) at a quartz reaction tube (4), charging a solution of a compound of a rare earth element as a solution into the section between the constricted portions (28) for doping. By this, the doping concentration becomes uniform along the length of an optical fiber preform (30) with defects being rarely produced. This process does not involve any complicated operation.A second process of the invention comprises impregnating a solution in the form of a mist in a soot-like core glass (26) by which it becomes possible to control the doping concentration in high accuracy.A third process of the invention comprises impregnating a solution while controlling the concentration in response to a quantity of a transmitted laser beam through a soot-like core glass (26), by which the doping concentration is ensured independently of the density of the soot-like core glass.