Abstract: A compact, low profile splicing system for joining optical fibers produces durable, low transmission loss fusion splices. The system employs active optical techniques such as profile alignment or local injection and detection to achieve optimized alignment of the fibers prior to fusion. Light injected into one fiber is propagated across the interface to a second fiber. A detector senses the intensity of the injected light in the second fiber. After the relative position of the fibers is manipulated to maximize the transmitted intensity, the fibers are fusion spliced using an electric arc discharge. The accurate alignment achievable using the local injection and detection system to drive adaptive fiber positioning affords a method for reliably producing low loss splices. The present system is compact and low in profile, making it operable in cramped quarters with limited clearance to adjacent equipment and structures and with only a minimal amount of free fiber slack available.

Abstract: The present invention provides a compact fusion welding apparatus for optical fibers which has simple construction and which can stabilized discharges of discharge electrodes. Tip ends of a pair of the discharge electrodes (discharge forming ends) (5) are arranged so as to oppose each other via a space. Between tip ends of the discharge electrodes (1), connection end faces of a pair of optical fibers (2) are arranged so that the connection end faces thereof are opposed to each other and the connection end faces of the optical fibers (2) are fusion welded by discharge heat from the discharge electrodes (1). Dielectric bodies (4) are provided along the longitudinal direction of the discharge electrodes (1) in a form so as to sandwich the discharge electrodes (1) from both sides thereof.

Abstract: A bridge fiber and a method of connecting two other dissimilar optical waveguide fibers is presented. The bridge fiber may be utilized to connect positive dispersion fibers or step index single mode fibers to compensative fibers, such as dispersion compensation fibers or dispersion-slope compensation fibers.

Abstract: Techniques and systems suitable for performing low-loss fusion splicing of optical waveguide sections are provided. According to some embodiments, multiple laser beams (from one or more laser) may be utilized to uniformly heat a splice region including portions of the optical waveguide sections to be spliced, which may have different cross-sectional dimensions. According to some embodiments, the relative distance of the optical waveguide sections and/or the power of the multiple laser beams may be varied during splicing operations.

Abstract: Systems and techniques are described for improving reproducibility in a pre-splice heat treatment. A heat treatment station is described for applying a pre-splice beat treatment to a lead end of a first optical fiber having a first modefield diameter. The heat treatment station comprises a base, and a fiber clamp for holding the first optical fiber such that a length of the lead end of the first optical fiber is positioned over a heat source mounted to the base. The heat source causes a controlled expansion of the first fiber modefield at the first fiber lead end to form an internal bridge. The heat treatment station further includes position adjustment means for adjusting the length of the first fiber lead end that is exposed to the heat source.

Abstract: A fiber collimator is provided, comprising at least two optical components, one of the optical components (e.g., an optical element such as a collimating lens or a plano-plano pellet) having a surface that has a comparatively larger cross-sectional area than the surface of the other optical component(s) (e.g., at least one optical fiber). The optical components are joined together by fusion-splicing, using a laser. A gradient in the index of refraction is provided in at least that portion of the surface of the optical element to which the optical fiber(s) is fusion-spliced or at the tip of the optical fiber. The gradient is either formed prior to or during the fusion-splicing. Back-reflection is minimized, pointing accuracy is improved, and power handling ability is increased.

Abstract: Systems and techniques are described for improving reproducibility in a pre-splice heat treatment. A heat treatment station is described for applying a pre-splice heat treatment to a lead end of a first optical fiber having a first modefield diameter. The heat treatment station comprises a base, and a fiber clamp for holding the first optical fiber such that a length of the lead end of the first optical fiber is positioned over a heat source mounted to the base. The heat source causes a controlled expansion of the first fiber modefield at the first fiber lead end to form an internal bridge. The heat treatment station further includes position adjustment means for adjusting the length of the first fiber lead end that is exposed to the heat source.

Abstract: In a fusion splicing method and device for ribbon optical fibers, bare fibers (I) of the ribbon optical fibers are arranged, in opposite direction to each other, on a fiber setup stage (10) having V-grooves. A discharge occurs between the discharge electrode rods (21,22). In order to set all of the bare fibers “f” into a uniform temperature area in a discharge area, a wide and length of the uniform temperature area is extended by applying to the discharge area an electric field generated by applying a desired voltage to fiber clamps (31) made up of a conductive material. Thereby, a good fusing and splicing process is performed by supplying a uniform amount of heat to all of the bare fibers “f”. Further, the above process is also performed while a desired voltage is applied to a conductive plate arranged under the fiber setup stage (10).

Abstract: Systems and methods are described for reducing splice loss in an optical transmission line. A described system includes fiber guides for holding a first fiber and a second fiber in position for splicing to each other at a splice point. A heat source applies sufficient heat at the splice point to cause the first and second fibers to be fused together at the splice point, and subsequently applied heat to the splice point after the splice has been completed. The system further includes a tensioning assembly for applying a controlled, non-zero tension to the first and second fibers after they have been spliced together.

Abstract: A fiber collimator is provided, comprising at least two optical components, one of the optical components (e.g., an optical element such as a collimating lens or a plano—plano pellet) having a surface that has a comparatively larger cross-sectional area than the surface of the other optical component(s) (e.g., at least one optical fiber). The optical components are joined together by fusion-splicing, using a laser. A gradient in the index of refraction is provided in at least that portion of the surface of the optical element to which the optical fiber(s) is fusion-spliced or at the tip of the optical fiber. The gradient is either formed prior to or during the fusion-splicing. Back-reflection is minimized, pointing accuracy is improved, and power handling ability is increased.

Abstract: A manufacturing apparatus and method of a fiber coupler is provided. A movable electric arc is employed to fuse more than two stacked fibers for manufacturing a fiber coupler having a small size and good environment stability. It is advantageous that the fiber coupler can be used in a SDH (Synchronous Digital Hierarchy) communication system, and the method also be used to manufacture the all-fiber CWDM (Coarse Wavelength Division Multiplexing) multiplexer which covers the E-band wavelengths and the sub-components of the OADM (Optical Add/Drop Multiplexer). And, all these functions are difficult to be achieved by the conventional techniques.

Abstract: Systems and methods are described for reducing optical fiber splice loss. A torch is described for performing a thermally-diffused expanded core (TEC) technique. The torch includes a hollow body. A conduit delivers a flammable gas to the hollow body. The flammable gas streams out of an array of orifices formed in the hollow body. The orifices are shaped and arranged in the array such that when the streaming gas is ignited, a substantially continuous elongated flame is created having a desired heating profile. Further described are a thermal treatment station incorporating a line torch and techniques for using an elongated flame to reduce optical fiber splice loss.

Abstract: A fusion splice including a first optical fiber having a first MFD and a first MFD expansion rate. The splice further includes a second fiber having a second MFD and a second MFD expansion rate, wherein the second MFD is lower than the first MFD. The second fiber comprises a core, a cladding radially surrounding the core, and a zone of high-concentration of fluorine between the core and the cladding. The rate of MFD expansion of the first fiber is less than the rate of MFD expansion of the second fiber during the fusion splicing operation.

Abstract: A method for producing fiber optic devices having improved intrinsic resistance to external environmental conditions and a fiber optic device made my the method are disclosed. The fabrication method produces an optic device that is treated with deuterium. The method includes a step for treating and/or making optical devices in the presence of a flame produced by the combustion of deuterium gas or a mixture including deuterium.

Abstract: The present invention discloses an HWDM (10) and a method of producing the same. The HWDM includes a WDM element (20), two receiving sleeves (30), (40), two shrink sleeves (50) and an outer tube (60). The WDM element includes a first, second, third and fourth optical fibers (21˜24). The first optical fiber is fused with the second fiber to form a first fusion region (211), and with the third fiber to form a second fusion region (212). The second fiber and the fourth fiber are fused to form a third fusion region (221). The receiving sleeves respectively contain the first fusion region and the second and third fusion regions therein. Each shrink sleeve attaches to a corresponding receiving sleeve. The outer tube receives two receiving sleeves therein.

Abstract: The present invention provides a compact fusion welding apparatus for optical fibers which has simple construction and which can stabilized discharges of discharge electrodes. Tip ends of a pair of the discharge electrodes (discharge forming ends) (5) are arranged so as to oppose each other via a space. Between tip ends of the discharge electrodes (1), connection end faces of a pair of optical fibers (2) are arranged so that the connection end faces thereof are opposed to each other and the connection end faces of the optical fibers (2) are fusion welded by discharge heat from the discharge electrodes (1). Dielectric bodies (4) are provided along the longitudinal direction of the discharge electrodes (1) in a form so as to sandwich the discharge electrodes (1) from both sides thereof.

Abstract: Techniques are described for reducing splice loss between a pair of optical fibers. A first fiber is spliced to a second fiber at a splice point. A region of the spliced fibers, including the splice point, is thermally treated to cause a controlled diffusion of dopants in the region. A controlled tension is then applied to the splice region while heating it to a predetermined temperature to produce a controlled change in the splice region's strain state. Further described is a heat and tension station for performing a heat and tension technique on a pair of spliced fibers.

Abstract: A method of splicing optical fibers is provided to reduce the splicing loss of the first and second optical fibers having different MFDs from each other. In a pre-fusion heating step, the MFD at the adjacent end face of the optical fiber having larger MFD is enlarged by heating a portion including the adjacent end face thereof so as to diffuse a dopant. After the pre-fusion heating step, fusion-splicing of the first and the second optical fibers is performed. Thereafter, during the post-fusion heating step, the dopant is diffused by heating a portion including the fusion-spliced part between the first and the second optical fibers.

Abstract: An optical fiber locking device is provided with a holder base, a table for support of an optical fiber, the table being fitted to the holder base and provided with a magnet and a slit, an openable and closable cover, being connected to the table by a hinge and detachably attached by the magnet and a sliding arm including a finger protruding out from the slit so as to operate the cover and a grip, and movably fitted to the holder base. When the grip is driven to a direction of the cover so as to drive the finger, the finger pushes the magnetically attached cover up so as to be opened.

Abstract: An optical cable has a reduced slicing loss and superior characteristics in the efficiency of the installation work thereof, and is therefore suitable for installation on land. First and second optical fibers have been connected together by fusion splicing to form joints thereby providing an optical fiber line. Each first optical fiber has a positive chromatic dispersion at a signal light wavelength while each second optical fiber has a negative chromatic dispersion at the same wavelength. The first and the second optical fibers, including the joints, are accommodated in the optical cable.

Abstract: The connecting method of different kind optical fibers of the present invention is a connecting method able to improve the strength of connecting portions of the different kind optical fibers of different mode field diameters. In this connecting method, connecting ends of the different kind optical fibers removing their coating therefrom are mutually butted and fusion-spliced by gripping the coating in a step (S4). Next, the mode field diameters of different kind optical fiber connecting portions are conformed to each other by the heat treatment of a step (S5). This heat treatment is taken within a low dust space having a clean degree of 1000 or less in class. Thus, the heat treatment is taken under an environment in which foreign matters floated around the connecting portions of the different kind optical fibers are very small. Therefore, it is possible to restrain a crack from being caused by burning the foreign matters into the connecting portions.

Abstract: A system is provided for fusion splicing at least one pair and, more typically a plurality of pairs (e.g., 24 pairs), of optical fibers together. The system includes a pair of electrodes and a controller. The optical fibers are positioned between the pair of electrodes. In this regard, the electrodes are capable of passing an electric current therebetween to create an electric arc capable of heating an end of each of the optical fibers. The controller is capable of controlling the electrodes to thereby pass the current therebetween to create the electric arc. Advantageously, the controller is capable of controlling the electrodes to pass an initial current to thereby create and maintain an initial electric arc and thereafter pass a processing current to thereby create and maintain a processing electric arc, where the initial current is higher than the processing current.

Abstract: An optical fiber transmission line including first, second and third optical fibers connected together so that light travels through the transmission line from the first optical fiber, then through the second optical fiber and then through the third optical fiber. The first, second and third optical fibers have first, second and third characteristic values, respectively. The second characteristic value is larger than the first characteristic value and the third characteristic value. The characteristic value of a respective optical fiber being a nonlinear refractive index of the optical fiber divided by an effective cross section of the optical fiber. Pump light is supplied to the transmission line so that Raman amplification occurs in the transmission line as an optical signal travels through the transmission line.

Abstract: The present invention relates to a fabrication method of an optical fiber product and others capable of effectively restraining increase of loss near the wavelength of 1.38 &mgr;m induced by OH-radical absorption. The fabrication method of the optical fiber product involves the steps of preparing two optical fibers with mutually different mode field diameters, and heating a region near a splice end face of at least one optical fiber with the smaller mode field diameter by a heating source not using a fuel containing pure hydrogen as a constitutive element, before or after a fusion splice is made between these optical fibers. This reduces the OH-radical absorption in the heated region, so as to decrease the increase of transmission loss at the wavelength of 1.38 &mgr;m to 0.1 dB or less.

Abstract: A method of terminating a polymer optical fibre (10) having a longitudinally extending light guiding cor region (11) and longitudinally extending channel-like light confining holes (13). The method comprises restricting a cross-sectional area of the some or all of the holes over a portion of their length adjacent and extending to a terminal end (14) of the optical fibre (10). The cross-sectional area of the holes is restricted, using the inherent properties of the polymeric material, in a manner effectively to increase the cross-sectional area of the light guiding region (11) of the optical fibre (10) adjacent its terminal end (14). Further, a method of splicing two of such polymer optical fibres (10) comprising terminating each of the optical fibres by the above-defined method, aligning them and conjoining their terminal ends (14).

Abstract: A low-cost approach provides a low loss and mechanically robust fusion splice between a standard silica fiber and a low-temperature multi-component glass fiber. An asymmetric heating configuration creates a temperature gradient between the silica and multi-component glass fibers that enhances diffusion, hence bond strength. The multi-component glass fiber may also be drawn with an outer cladding of a different multi-component glass. The outer cladding is selected so that it is thermally compatible with the multi-component glass used for the core and inner cladding and compatible with forming even stronger thermal diffusion bonds with the silica fiber.

Abstract: An optical fiber splicing method capable of fully reducing the splice loss at room temperature is provided. In the optical fiber splicing method in accordance with the present invention, respective end faces of optical fibers are fused together in a splicing step (S101). In a condition setting step (S102), a set value &agr;0 is set. Thereafter, a heating step (S103), a measuring step (S104), and a termination determining step (S105) are carried out repeatedly. In the heating step, a region including the fusion-spliced point is heated under a predetermined heating condition. In the measuring step, splice loss is measured. In the termination determining step, the splice loss &agr;n measured in the measuring step and the set value &agr;0 set in the condition setting step are compared with each other in terms of magnitude.

Abstract: It is an object of the invention to provide an apparatus and method for fusion splicing the optical fibers under the fusion splicing conditions suitable for respective optical fibers in which the types of optical fibers can be fully discriminated.

Abstract: Each of optical fibers has a core and stress applying members disposed around the core. End portions of the optical fibers are mounted on a fusion-splicing apparatus, and aligned through the image observation from two different lateral directions of the optical fibers. Then, a distance between positions of a bright portion end and a luminance peak closest to the bright portion end is obtained on each bright portion end of a luminance distribution of the optical fiber obtained from at least one picked-up image. The optical fibers are fusion-spliced by aligning the stress applying members so that the sum of the distances is adjusted to be minimum. Alternatively, a distance between positions of the luminance peaks respectively closest to the respective bright portion ends is obtained and the optical fibers are fusion-spliced by aligning the stress applying members so that the distance is adjusted to be maximum.

Abstract: A technique for manufacturing optical fixed attenuators in which two fibers are axially cojoined using fusion splicing. The spliced fibers are then captured in either a splice protection splint or cylindrical ferrule that can be housed in an optical adapter. In this process for producing the attenuator, the fusion splicing is preceded by a deformation of the mode field diameters of the ends of the fibers with the cleaning arc function of the splicing unit. The resulting attenuation of the splice is dependent on the amount of deformation of the fiber core and mode field diameter. Such a technique enables precision attenuation with very low wavelength dependent loss to be fabricated. The performance of Dense Wavelength Division Multiplexing systems, as well as test facilities and individual optical components can be improved by the use of such attenuators.

Abstract: An optical fiber of a bundled fiber light source is an optical fiber whose core diameter is uniform but whose emission end cladding diameter is smaller than an incidence end cladding diameter thereof, and a light emission region thereof is made smaller. An angle of luminous flux from this higher luminance bundled fiber light source, which passes through a lens system and is incident on a DMD, is smaller, i.e., an illumination NA is made smaller. Thus, an angle of flux which is incident on a surface that is to be exposed is smaller. That is, a minute image formation beam can be obtained without increasing the image formation NA, focal depth is lengthen.

Abstract: Systems and techniques are described for fabricating a low-loss, high-strength optical transmission line. In one described technique, a first fiber is spliced to a second fiber at a splice point. The spliced fibers are loaded into a heat treatment station, where a gas torch flame is used to thermally treat a splice region including the splice point, with the thermal treatment reducing splice loss between the first and second fibers. While heating the splice region, a dry gas is purged around the torch flame during the heat treatment process to avoid water at the surface of the spliced fibers. According to further described techniques, a purging gas is fed to the torch flame to purge dust particles from the flame, and after the heat treatment has been completed, the torch flame is used to restore the glass surface of the spliced fibers. Additionally described are torch assemblies for fabricating low-loss, high-strength optical fiber transmission lines.

Abstract: In a method for fusing splicing optical fibers having different diameters of fiber coating portions, the fiber coating portions of optical fibers to be spliced are clamped on V-groove boards and end faces of the optical fibers are aligned. Then, the end faces of the optical fibers are fused spliced by a discharged heating. An inclination angle &thgr;g of glass fibers of the fusion spliced optical fibers is measured from an observed image of a fusion splicing portion after fusion splicing the optical fibers to estimate a splice loss of the optical fibers.

Abstract: A method of controlling an optical fiber splicing machine utilizes a power control mode to control the amount of power delivered to fuse the fibers. In the power control mode, the attenuation is measured while the fusing process is occurring. A rate of attenuation loss is predicted from the measured attenuation values by using an estimator. If the rate of attenuation loss indicates that a threshold insertion loss will be crossed before the next attenuation measurement, the splicing machine is stopped prior to the next attenuation measurement. If the desired attenuation is not achieved, an energy control mode is utilized which controls the amount of energy delivered to fuse the fibers. After delivering this energy, the method measures the attenuation. If not within desired values, the energy mode is repeated. At each iteration the splicing control function utilized by the energy control mode may be reprogrammed. A PID control formula may be used to determine the arc current for each iteration.

Abstract: An optical fiber holder is provided which can accurately position the tip of an optical fiber during fusion-splice. A holder 2 can be used without removing an optical fiber 1 clamped in a stripping apparatus, cleaving apparatus and fusion-splicing apparatus in common. The optical fiber is clamped between a holder main body 2a and clamping members 3a, 3b at the coated portion thereof and between a V-groove portion 2b and a clamping member 7 at the tip thereof. The holder is positioned and mounted on a holder mount 4. Since the optical fiber is kept clamped in the holder throughout the steps of stripping, cleaving and fusion-splicing, the tip of the optical fiber 1a can be accurately positioned during fusion-splice.

Abstract: Methods for connecting two optical fibers having different mode field diameters ((MFD) with low connection loss is proposed. One method comprises steps of preparing the third fiber (Fiber 3), a short length and MFD being smaller than that of the first fiber (Fiber 1) and larger than that of the second (Fiber 2), connecting the Fiber 1 to 3, connecting Fiber 2 to 3, and increasing MFD of Fiber 3 near the part connected or to be connected to Fiber 1, or MFD of Fiber 2 near the part connected or to be connected to Fiber 3 by heating the corresponding part. The other method comprises steps of preparing a short length Fiber 3 having smaller MFD than that of Fiber 1, increasing MFD of Fiber 3 near the part to be connected to Fiber 1 by heating the corresponding part, and then connecting Fiber 1 to 3, and 3 to 2 in that order.

Abstract: A method for splicing optical fibers includes securing a first optical fiber and a second optical fiber within an apparatus, stripping a coating from about the first optical fiber by a first laser beam generated from at least one laser, and stripping a coating from about the second optical fiber by the first laser beam. The method also includes cleaving an end of the first optical fiber via a second beam from the laser, and cleaving an end of the second optical fiber via the second laser beam. The method further includes splicing the ends of the optical fibers together via a third laser beam from the laser, thereby creating a fused connection between the first optical fiber and the second optical fiber, and removing the first and second optical fibers from within the apparatus.

Abstract: The present invention includes a composite optical waveguide fiber. The composite optical waveguide fiber includes a first optical waveguide fiber. The first optical waveguide fiber has a first diameter and a first outermost layer having a first coefficient of thermal expansion. The composite optical waveguide fiber further includes a second optical waveguide fiber coupled to the first optical waveguide fiber. The second optical waveguide fiber has a second diameter and a second outermost layer, the second outermost layer having a second coefficient of thermal expansion. Wherein the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion. Wherein the first diameter is greater than the second diameter.

Abstract: A temperature stabilized tapered fiber optic component is produced, such as a fiber optic coupler or a fiber optic filter. In the case of the component such as a coupler, at least two fibers are fused and tapered to achieve a desired taper profile with suitable mechanical and wavelength properties. In the case of a component such as a fiber filter, only one fiber is tapered. Once the component is formed, it is solidly secured to a rigid substrate that produces a mechanical stress such as to compensate for any modal phase shift of the component due to temperature variation. Also, the mechanical phase dependence of the component may be adjusted in relation to the substrate to provide the desired temperature compensating effect. Preferably, both these features are used to achieve the best possible temperature stabilization.

Abstract: The Stand-Off Fusion-terminated optical interface reduces optical reflections thereby increasing return losses that occur when an optical waveguide, including optical fibers, is interfaced to a bulk media of significantly differing refractive index. A small spacer material, or stand-off, is placed between the optical waveguide and the media. The stand-off is index-matched to the optical waveguide thereby eliminating reflections from this interface. The length of the stand-off is chosen so the reflections from the stand-off/media interface are weakly coupled back to the optical waveguide due to diffraction and attenuation losses within the stand-off. The optical waveguide is then fused to the stand-off by focusing a time variable laser beam at the junction of the optical waveguide and the stand-off.

Abstract: An optical splice joint and splicing process are provided for joining an end portion of a microstructured optical fiber having a microstructure formed from an array of holes, and a conventional optical fiber. The optical splice joint is formed from a fused portion of opposing end portions of the microstructured optical fiber and optical fiber, wherein the microstructured optical fiber is surrounded by a jacket that is at least 1.6 times thicker along its radius than the microstructure, and has a tensile strength of at least 30 Kpsi with an optical loss of less than 0.30 dB, and relatively little shrinkage (i.e., about 30%) of the holes forming the microstructure. The splice joint is formed by aligning end portions of the microstructured optical fiber and the optical fiber, in a fusion splicer, and applying fusion heat to the fiber ends in a two step process with a low current arc that is offset with respect to the end of the microstructured optical fiber.

Abstract: A method for handling a fusion-spliced optical fiber and a transferring jig for transporting the optical fiber are provided. The jig is capable of holding the fusion-spliced optical fiber in a state in which a given tension is applied at the spliced portion, and stopping the application of such tension if needed. The jig is easy to transport and set to each of separate processing processes. In the method, a fusion-spliced optical fiber is clamped at coated portions thereof on both sides of the fusion-spliced portion by a pair of clamps of the jig and transported by the jig holding the optical fiber in a state wherein a given tension is applied thereto through the clamps.

Abstract: The present invention relates to an optical fiber transmission line having a structure offering superior connection loss characteristics at the fusion-spliced position between optical fibers. This optical fiber transmission line has at least first and second optical fibers that are fusion-spliced. Each of these first and second optical fibers has a core region doped with 10 mol % or more of Ge and has a mode field diameter with a minimum value of 7 &mgr;m or less at the wavelength of 1550 nm. The difference between the minimum mode diameter of the first optical fiber and that of the second optical fiber is 1 &mgr;m or less.

Abstract: An assembly for combining the outputs from a group of n single mode optical fibres on to the photosensitive surface of a photodetector (1) has an adiabatically tapered bundle (2) of fibres (3) the small end of which is fusion spliced to one end of a length (4) of multimode fibre whose other end is optically coupled with the detector (1) by means of a lens (5).

Abstract: A method is described for producing a fiberoptic waveguide with a basic segment (11) and a phase shift segment (12), the basic segment (11) and phase shift segment (12) having fiber cores (K) of the same form and the fiber cores being aligned at a defined angle (&agr;) to one another. In the method, use is made of an optical fiber (1) having a fiber core (K) of the abovenamed form, which fiber is twisted at least approximately by the abovenamed defined angle (&agr;) and held fixed in this torsional position. Subsequently, a stress-relief zone (13) is heated inside the twisted fiber (1) until the torsion is released inside the stress-relief zone (13) and the basic segment (11) is produced on one side of the stress-relief zone (13) and the phase shift segment (12) is produced on the other side. In this case, the fixing of the torsional position is maintained until after solidification of the stress-relief zone (13).

Abstract: Provided are a method of splicing together multiple fibers having different mode field diameters (MFDs) en bloc at a low splicing loss and a multi-fiber component incorporating the fibers thus spliced. After a fusion-splicing operation has been conducted, additional heat treatment is applied to the portion of the fibers thus fusion-spliced so that a dopant contained in the core portions of the fibers is thermally diffused so as to cause the MFDs thereof to match each other. The multiple fibers are disposed in parallel in line. During the fusion-splicing operation, one or both of pairs of fibers 11a and 11b are pushed toward the other to face each other, and the fibers are pulled back in the opposite direction to decrease diameter increment created in fusion spliced portions, and then additional heat treatment is applied to the fusion-spliced portions 16.

Abstract: This invention provides a connecting method and the like for between optical fibers with little connection loss without heat treatment after fusion-splicing. This connecting method is a method of optically connecting first and second optical fibers which differ in core diameter to such an extent that the fusion-splicing loss is 0.45 dB or more. In the method, a connecting member is prepared between these first and second optical fibers, and the two end faces of the connecting member are directly fusion-spliced to one end face of the first optical fiber and one end face of the second optical fiber, respectively. The prepared connecting member, in particular, is comprised of a third optical fiber whose core diameter is large enough to exhibit a fusion-splicing loss of 0.45 dB or less at a wavelength of 1.55 &mgr;m when it is connected to the first optical fiber, and a fourth optical fiber whose core diameter is small enough to exhibit a fusion-splicing loss of 0.

Abstract: A composition of phosphate-based glass fiber capable of being fused directly to a silica-based glass fiber includes from about 60 mole % to about 75 mole % P2O5, from about 8 mole % to about 30 mole % X203, from about 0.01 mole % to about 25 mole % of R2O. X is selected from the group of Al, B, La, Sc, Y and combinations thereof. R is selected from the group of Li, Na, K and combinations thereof. Optionally, the phosphate-based glass fiber may include 0.5 to 10 mole % MO, where M is selected from Mg, Ca, Sr, Ba, Zn, and combinations thereof. The composition preferably further includes from about 0.5 mole % to about 15 mole % of an additional component from the group of Si, Ge, Pb, Te and combinations thereof.

Abstract: A fiber optic device for changing direction along a fiber optic path is provided. A first optical fiber having a first end portion, and a second optical fiber having a second end portion are joined at a fusion splice. A miniature bend is formed in the region of the fusion splice. The device is particularly useful for routing optical fibers in the field. A method of forming such a miniature bend in a fusion splice region between two optical fibers is also provided.

Abstract: A fiber splicing apparatus of the present invention includes a support (120a, 120b) for supporting the two optical fibers (112a,112b) such that the ends (114a, 114b) thereof are aligned and in physical contact, and a laser (130) emitting a laser beam (142) onto the ends of the optical fibers to heat and thereby fuse together the ends (114a, 114b ) of the fibers (112a, 112b). According to another embodiment, an apparatus is provided for heating a region (115) of one or more optical fibers(112a, 112b). This apparatus includes a laser (130) emitting a laser beam (132) and an optical modulator (134) positioned to receive and selectively modulate the intensity of the laser beam (132) to project a modulated laser beam (138) along a first optical path that terminates at the end (114a, 114b ) of the optical fiber(s) (112a, 112b)to be heated.