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公开(公告)号：JPH05100119A
公开(公告)日：1993-04-23
申请号：JP25937191
申请日：1991-10-07
Applicant: FUJITSU LTD
Inventor： ARIMA TADAO , OKAMURA KOJI
Abstract: PURPOSE:To prevent the damaging of an optical fiber and the scorching of the residues of its coating by blowing fine powder consisting of a material having the hardness between the hardness of the optical fiber and the hardness of the coating by a high-pressure gas to the coating of the optical fiber. CONSTITUTION:The fine powder consisting of a material having the hardness between the hardness of the optical fiber 2 and the hardness of the coating 4 is blown by the high-pressure gas to the coating 4 of the optical fiber 2. Namely, the fine powder is supplied to a nozzle 20 by a low-pressure gas (carrier gas) via a high-pressure gas supplying pipe 34. This fine powder is mixed with the high-pressure gas in the nozzle 20 and the mixture composed thereof is blown from a discharge port provided at the bottom end of the nozzle 20 toward the coated optical fiber 16. For example, aluminum, brass, iron, copper, carbon, etc., can be adopted as the material of the fine powder in such a case. Then, the fine powder can be blown to the required range in the longitudinal direction of the coated optical fiber 16 and the coating 4 can be removed only for the necessary parts in the longitudinal direction of the coated optical fiber 16.
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公开(公告)号：JPH04324403A
公开(公告)日：1992-11-13
申请号：JP9454291
申请日：1991-04-25
Applicant: FUJITSU LTD
Inventor： ARIMA TADAO , OKAMURA KOJI
Abstract: PURPOSE:To sharpen the boundary between a part where a coating is removed and a part where the coating remains and to decrease the fluctuations in coating length as well as to obviate the degradation in the strength of the optical fiber by irradiating the coated optical fiber with a YAG laser beam to melt the secondary coating material of the fiber and blowing gas thereto to blow off the molten coating material. CONSTITUTION:The prescribed point of the coated optical fiber 1 to be subjected to the removal of the coating is irradiated with the YAG laser beam 15 by which the secondary coating material 4 is heated to melt. While the molten coating material 4A is blown off by ejecting the gas 25 from a nozzle 20, a laser emission optical system 11 and the nozzle 20 are moved by as much as the length to be removed along the coated optical fiber 1, by which the secondary coating material 4 is removed. The optical fiber 2 and the silicone coating layer 3 do not absorb the YAG laser beam and are, therefore, not heated up to the melting temp. of the secondary coating material 4 or above and the silicone coating layer 3 remains on the optical fiber 2 side. The optical fiber is stored in this state and the silicone coating layer 3 is removed by rubbing the layer with fingers just before the fiber is made into, for example, a fiber fusion type optical coupler.
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公开(公告)号：JPH04156431A
公开(公告)日：1992-05-28
申请号：JP27923390
申请日：1990-10-19
Applicant: FUJITSU LTD
Inventor： OKAMURA KOJI , ARIMA TADAO
Abstract: PURPOSE:To adjust the wavelength characteristic of gain according to the wavelength of injected signal light by installing an optical fiber in a magnetic field, and adjusting the strength of the magnetic field according to the wavelength of the injected signal light. CONSTITUTION:Signal light of wavelength lambdaS is injected from one end of an Er-doped optical fiber 1 doped with erbium Er, and excitation light of wavelength lambdaP is combined with the signal light through a wave combiner or the like so as to amplify the signal light. A part of the Er-doped optical fiber is wound into coil shape, and this coil-shape wound part 1a is disposed on the inner side of a cylindrical electromagnet 2. The strength of the magnetic field formed by the electromagnet 2 can be adjusted according to the wavelength lambdaS of the signal light by disposing the Er-doped optical fiber 1 in the magnetic field formed by the electromagnet 2, so that the magnetic field of the highest gain to the wavelength lambdaS of the signal light can be formed by the electromagnet 2. The wavelength characteristic of the gain can be thereby adjusted according to the wavelength of the injected signal light.
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公开(公告)号：JPH0429028A
公开(公告)日：1992-01-31
申请号：JP13415290
申请日：1990-05-25
Applicant: FUJITSU LTD
Inventor： OKAMURA KOJI , ARIMA TADAO
Abstract: PURPOSE:To allow measurement with high accuracy by making the light of a wavelength at which the light absorption by a doped element is large to enter an optical fiber base material doped with the rare earth element and determining the concn. distribution of the doped rare earth element. CONSTITUTION:When light of 1.53 mum wavelength is exitted from an LED 22, the exit light is made incident via an optical fiber 20 and a fiber assembly 18 on a lens system 2b, is collimated and is made incident uniformly over the entire surface at one end face of the Er-doped fiber base material 10, by which the base material 10 is uniformly excited. The opposite side end face of the base material 10 is then photographed by an IR camera 30 and the core and clad surfaces of the base material 10 are monitored by a monitor 36. The light intensity is observed on the monitor 36 in such a manner that the light intensity is smaller in the Er-doped core 40 part than in the clad 42 part as the light of 1.53 mum wavelength is obsorbed in this core part. Further, the output of the camera 30 is taken into a personal computer 38 and is subjected to image processing, by which the Er concn. distribution is determined from the light distribution intensity. The result thereof is printed out as a hard copy 46.
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公开(公告)号：JPH03263006A
公开(公告)日：1991-11-22
申请号：JP6327190
申请日：1990-03-14
Applicant: FUJITSU LTD
Inventor： OKAMURA KOJI , ARIMA TADAO
IPC: G02B6/42
Abstract: PURPOSE:To improve the optical coupling efficiency between an optical fiber and a light receiving element by incorporating the optical fiber and a semispherical lens in a ferrule and converging the light from the semispherical lens on the light receiving face of the light receiving element. CONSTITUTION:This device is provided with an axial center hole 11, a lens storage chamber 12 provided on the extension to the axial center hole 11 and a ferrule 10 provided with an outgoing hole 13 opened in a prescribed position of the side wall of the lens storage chamber 12. The optical signal propagated in an optical fiber 1 is conically emitted from the plane end face of the optical fiber 1 and is made incident on a semispherical lens 15 and is turned at 90 deg. by the cut face of the semispherical lens 15 and is reflected toward an exit hole 13 and is converted to a condensed beam by the lens action of the lower spherical face and passes through the exit hole 13 and is converged on a light reception face 6a of a light receiving element 6. The spherical lens is produced and a part or a half of the sphere is removed by polishing to provided the cut face, thereby obtaining the semispherical lens 15. That is, the semispherical lens not only is easy to produce to have a high yield but also has the spherical face of fixed curvature. Thus, the optical coupling efficiency between the fiber 1 and the element 6 is improved.
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Patent Agency Ranking
公开(公告)号：JPH03214125A
公开(公告)日：1991-09-19
申请号：JP831890
申请日：1990-01-19
Applicant: FUJITSU LTD
Inventor： OKAMURA KOJI , ARIMA TADAO
Abstract: PURPOSE:To decrease the coupling loss to a fiber for a transmission path by fusing the side face of a 2nd optical fiber having the mode field diameter approximately equal to the mode field diameter of the fiber for the transmission path near to the end part on the down stream side in the propagating direction of the signal light and stimulating light of a rare earth-doped fiber and stretching the fused part. CONSTITUTION:The side face of the 1st optical fiber 2 where the signal light propagates is fused near to the end part on the incident side of the stimulating light of the rare earth-doped fiber 1 and the fused part is stretched to constitute the ampli fier in such a manner that the signal light and the stimulating light propagate in the rare earth-doped fiber 1. The side face of the 2nd optical fiber 3 having the mode field diameter approximately equal to the mode field diameter of the fiber for the transmission path is fused near to the end part on the down stream side in the propa gating direction of the signal and stimulating light of the rare earth-doped fiber 1 and the fused part is stretched to constitute the amplifier in such a manner that only the signal light amplified in the rare earth-doped fiber 1 is coupled to the 2nd optical fiber 3. The increase in the coupling loss by a difference in the mode field diameter is prevented in this way.
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公开(公告)号：JPH03214108A
公开(公告)日：1991-09-19
申请号：JP831790
申请日：1990-01-19
Applicant: FUJITSU LTD
Inventor： ARIMA TADAO , OKAMURA KOJI
IPC: G02B6/28
Abstract: PURPOSE:To facilitate the production of the coupler by fusing the side faces of two pieces of single mode fibers varying in structural parameters, then stretching the fused part until a prescribed outside diameter is attained. CONSTITUTION:The side faces of two pieces of the single mode fibers 16, 18 varying in the structural parameter are fused and the fused part is stretched until the outside diameter of the fused part is reduced to about 1/4 to 1/2 the outside diameter before the stretching. The max. coupling ratio in a required wavelength range is no longer increased to 100% and the wavelength at which this max. coupling ratio is attained can be set according to the outside diameter or length of the final fused and stretched part. Namely, the branching by approximately the same branching ratio with light of respective wavelengths is executed. The production of the fiber fusion type optical coupler of a broad wavelength region is facilitated in this way.
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公开(公告)号：JPH03211504A
公开(公告)日：1991-09-17
申请号：JP641890
申请日：1990-01-17
Applicant: FUJITSU LTD
Inventor： OKAMURA KOJI , ARIMA TADAO
IPC: G02B6/00 , C03B37/014 , C03B37/018 , H01S3/06 , H01S3/067 , H01S3/17
Abstract: PURPOSE:To prevent the extreme decrease in the concn. of the rare earth element in the central part of a core by forming 1st core glass which is not doped with the rare earth element, then forming 2nd sooty core glass doped with the rare earth element and executing final collapse. CONSTITUTION:The fine powder of the oxide glass generated by a vapor reaction is stuck in a quartz reaction tube 22 to form the 1st sooty core glass 24. The 1st sooty core glass 24 is vitrified and the quartz reaction tube 22 is subjected to the primary collapse. The fine powder of the oxide glass generated by the vapor reaction is stuck onto the vitrified 1st core glass 24' to form the 2nd sooty core glass 26 and a soln. consisting of a rare earth element compd. as its solute is impregnated in the 2nd sooty core glass 26. This 2nd sooty core glass 26 is vitrified and is subjected to the final collapse to obtain the preform 34. The rare earth-doped fiber which is not extremely low in the rare earth element concn. in the central part of the core is obtd. in this way.
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公开(公告)号：JPH03210508A
公开(公告)日：1991-09-13
申请号：JP758390
申请日：1990-01-16
Applicant: FUJITSU LTD
Inventor： ARIMA TADAO , OKAMURA KOJI
IPC: G02B6/28
Abstract: PURPOSE:To adjust a taper angle to a prescribed value by inputting the image of a fusion part of two optical fibers, executing image processing to find out the taper angle and controlling a heating range adjusting means by using the obtained taper angle. CONSTITUTION:The optical fibers 10, 20 are heated and fused by a burner 30 and the shape of the fusion part is inputted to an image processor 61 by a television camera 51 to calculate the taper angle. An interval between shielding plates 71, 72 is adjusted by moving pulse stages 73, 74 so that the calculated taper angle coincides with a previously set angle. Since a separation waveguide is determined by the taper angle when a coupling period is fixed, the taper angle can be determined in accordance with the determination of a required separation wavelength. Thus, the tape angle for determining the separation wavelength can be adjusted to an optional value.
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公开(公告)号：JPH0297905A
公开(公告)日：1990-04-10
申请号：JP24980588
申请日：1988-10-05
Applicant: FUJITSU LTD
Inventor： OKAMURA KOJI , ARIMA TADAO
IPC: G02B6/28
Abstract: PURPOSE:To obtain the optical device which decreases an excess loss and fluctuation in a branching ratio by pressing the side faces of two pieces of optical fibers to each other, independently supporting one thereof, applying a weight thereto, heating the contact part and subjecting the contact part to fusion stretching. CONSTITUTION:The optical fibers 1 are crimped by guides 6 and the side faces thereof are pressed to each other in the contact part 3. The one side thereof is independently supported 2. While the weight W is uniformly applied to each of the supporting parts, the contact part 3 is heated and is subjected to fusion stretching. Since the one side of the fibers is independently supported and stretched by each of the fibers in such a manner, the weight W is uniformly applied on the optical fibers and the nonuniformity in the shape of the stretched parts by the nonuniform application of tension is obviated. The deterioration by the increase of the excess loss and the fluctuation in the branching ratio is, therefore, prevented.
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