CN1109661C - Method of making optical fibers - Google Patents
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- CN1109661C CN1109661C CN97190447A CN97190447A CN1109661C CN 1109661 C CN1109661 C CN 1109661C CN 97190447 A CN97190447 A CN 97190447A CN 97190447 A CN97190447 A CN 97190447A CN 1109661 C CN1109661 C CN 1109661C
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/018—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02214—Optical fibres with cladding with or without a coating tailored to obtain the desired dispersion, e.g. dispersion shifted, dispersion flattened
- G02B6/02219—Characterised by the wavelength dispersion properties in the silica low loss window around 1550 nm, i.e. S, C, L and U bands from 1460-1675 nm
- G02B6/02247—Dispersion varying along the longitudinal direction, e.g. dispersion managed fibre
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
- C03B37/01211—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments by inserting one or more rods or tubes into a tube
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
- C03B37/01225—Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing
- C03B37/01248—Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing by collapsing without drawing
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/01486—Means for supporting, rotating or translating the preforms being formed, e.g. lathes
- C03B37/01493—Deposition substrates, e.g. targets, mandrels, start rods or tubes
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/028—Optical fibres with cladding with or without a coating with core or cladding having graded refractive index
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
- G02B6/03638—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 3 layers only
- G02B6/03644—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 3 layers only arranged - + -
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2203/00—Fibre product details, e.g. structure, shape
- C03B2203/10—Internal structure or shape details
- C03B2203/18—Axial perturbations, e.g. in refractive index or composition
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2203/00—Fibre product details, e.g. structure, shape
- C03B2203/36—Dispersion modified fibres, e.g. wavelength or polarisation shifted, flattened or compensating fibres (DSF, DFF, DCF)
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
- C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
- C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
- Y02P40/57—Improving the yield, e-g- reduction of reject rates
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- Chemical & Material Sciences (AREA)
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- General Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Geochemistry & Mineralogy (AREA)
- Optics & Photonics (AREA)
- General Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Thermal Sciences (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
Abstract
A preform (94) for making an optical fiber is made by depositing silica soot (91) around a tube (90). Pieces of differing glass compositions (81, 82) are placed in the bore of the tube. This preform is then sintered, fused and collapsed. A draw blank is obtained which can be drawn into a low-loss, dispersion managed, single-mode optical fiber.
Description
Background technology
The present invention relates to a kind of method of making optical fiber, the optical property of described optical fiber is made system change along fiber lengths.This method is particularly useful to the single mode waveguide optical fiber of making dispersion controlled system (DM).
Have only optimization system design, total dispersion is equalled zero or approaching equalling zero in the operating wave strong point, just may make single-mode fiber have bigger bandwidth.Term " chromatic dispersion " is meant pulse strenching, and its unit is ps/nm-km." chromatic dispersion long-pending " is meant that chromatic dispersion multiply by length, and its unit is ps/nm.
When communication network used multichannel communication or wavelength-division multiplex, system can produce loss because of four-wave mixing.When signal wavelength is in or during near the zero-dispersion wavelength of Transmission Fibers, just this loss can takes place.Need to explore the waveguide fiber design that can reduce to cause signal degradation because of the waveguide non-linear effect.When should keeping spacing is very big between the revivifier the required characteristic of system to reduce the waveguide fiber of four-wave mixing again, design run into difficulty.That is, in order to eliminate four-wave mixing basically, the total dispersion that waveguide fiber should not be operated in it approaches zero wavelength place, because four-wave mixing can take place when waveguide dispersion little (promptly less than about 0.5ps/nm-km).On the other hand, be the signal at zero place for wavelength departure waveguide total dispersion, owing to existing total dispersion to degenerate.
Overcome a kind of countermeasure of this difficulty, the system that the waveguide fiber section of optical cable is made in an employing is constructed in suggestion like this, make some fiber segment have positive total dispersion, and some fiber segment has negative total dispersion.If for all cut cables, the length weighted mean of chromatic dispersion approaches zero, and then the spacing of revivifier can be very big.Yet signal does not approach zero waveguide length basically by chromatic dispersion, thereby has avoided four-wave mixing.
The problem of this countermeasure is that every section link between the revivifier must customize, to provide the length weighted mean of required chromatic dispersion.Keep the optical cable chromatic dispersion identical to the fabricating yard from optical cable manufacturing works, be a undesirable special duty be again a source of error.In addition,, also to provide suitable cable length, thereby increase difficulty of making and the cost that causes increasing system with this dispersion values because the suitable dispersion value need not only be provided.When people consider to need to replace optical cable, also other problem can appear.
The optical fiber that is disclosed in No. the 08/584th, 868, the U.S. Patent application that people such as Berkey submitted on January 11st, 1996 has overcome these problems.According to the principle in people's such as Berkey the patent application, with every each other optical fiber as dispersion controlled system independently.For every waveguide fiber, design the length weighted mean (that is, total dispersion is long-pending) of the total dispersion of a preliminary election.Every waveguide fiber can both be exchanged with other any waveguide fiber for this system link design.Like this, the waveguide fiber of making optical cable all has the long-pending characteristic of identical substantially chromatic dispersion, thereby does not need to stipulate one group of special optical cable for the special part of system.When total link dispersion remains on the value (this value can be substantially equal to zero value) of a preliminary election, eliminated the power loss that produces owing to four-wave mixing basically.Perhaps it is reduced to the size of preliminary election.
According to people's such as Berkey patent application, the DM CHROMATIC DISPERSION IN FIBER OPTICS changes between a scope and a negative value scope one along waveguide length.To be that the chromatic dispersion of particular length l of unit is long-pending with ps/nm be, and (D ps/nm-km's * 1km) is long-pending.Positive ps/nm value will be offset the negative ps/nm value that equates.Generally, with length l
iThe chromatic dispersion that is associated can be along l
iPointwise changes.That is, though chromatic dispersion D
iIn the pre-determined range of chromatic dispersion, but can be along l
iPointwise changes.Be expression l
iFor unit is the long-pending contribution of chromatic dispersion of ps/nm, uses segment dl
iAccumulation and draw l
i, and in each segment, corresponding total dispersion D
iBasically constant.So product dl
i* D
iWith characterized l
iTo the long-pending contribution of chromatic dispersion.Note, getting dl
iDuring the limit that goes to zero, product dl
i* D
iAnd be dl
i* D
iIn length l
iOn integration.If chromatic dispersion is constant substantially in minute length l, then product and be exactly li * D
i
By controlling each segment dl
iChromatic dispersion D
iAnd control the chromatic dispersion of total waveguide fiber lengths, thereby in the reusable wavelength region of signal, make product D
i* dl
iAnd equal the value of a preliminary election.For high data rate systems, be good from the low decay window of 1525 nanometer to 1565 nanometers, choosing wavelength region approximately with long revivifier spacing.In this case, must in this wavelength region, make the DM CHROMATIC DISPERSION IN FIBER OPTICS long-pending and be target with zero.D
iSize remain on more than the 0.5ps/nm-km, preventing four-wave mixing basically, and with D
iSize be maintained at about below the 20ps/nm-km, thereby the waveguide fiber parameter does not need excessive swing.
Usually, a given total dispersion continues the length of existence greater than about 0.1km.This length lower limit has reduced the power loss (see figure 5), and has simplified manufacturing processed.
Is the period definition of DM single mode waveguide three segment length sums, first length has the total dispersion in first scope, second length has the chromatic dispersion in second scope, and first and second scopes are contrary signs, first length and the second length addition, add one section transition length, in this length, a transition is done in chromatic dispersion between first and second scopes.For avoiding four-wave mixing and any power loss that is associated in transition length, keep the part (total dispersion that is associated that it has is less than about 0.5ps/nm-km) of transition length short more good more.
If the transitional region between the higher and low dispersion area is oversize, its chromatic dispersion of optical fiber that certain-length will be arranged at the transitional region middle body is near zero.This will cause some power losses of producing owing to four-wave mixing.Transitional region is long more, and then power loss is big more.So transitional region should be enough precipitous, make the power loss of optical fiber can not make total system power loss surpass the power loss budget that distributes.
The basic demand of DM optical fiber manufacturing processed is to form short transitional region.In addition, DM optical fiber manufacturing processed itself should not cause and the unrelated excess loss of four-wave mixing.Process also should make it to realize with multiple optical fiber designs and material simply with enough flexible.Therefore, DM optical fiber must be the whole optical fiber that forms by stretch a wire drawing prefabricated rods or wire drawing blank, and the wire drawing prefabricated rods comprises and will form the part of the different optical fiber segment of chromatic dispersion.Whole optical fiber is not like this having joint between the tensile fiber segment respectively, because each joint all can cause excess loss.In the ideal case, the overall attenuation of whole optical fiber can not form the combination of weighting decay of the continuous placement fiber segment of optical fiber greater than each.
The method of attempting to add flame with lathe is fused together fibre core core material (cane) section, thereby forms DM fiber core rod.Except being difficult to realize, this method also exists fibre core not aim at, and flame can cause that fibre core becomes problem such as wet.
Summary of the invention
Therefore, an object of the present invention is to provide a kind of optical characteristics along the visibly different optical fiber of its length, and make improving one's methods of this optical fiber.Another purpose provides a kind of method of making the above-mentioned type optical fiber, and in this optical fiber, the transition length between the different fiber segment of characteristic is very short.Another purpose provides a kind of method of making the above-mentioned type optical fiber, and in this optical fiber, it is enough low to decay, and can be used as long Distance Transmission optical fiber.Another purpose provides a kind of method of short low-loss single-mode DM optical fiber of transition length of making.Another kind of purpose provides a kind of optical fiber of making the low polarization mode chromatic dispersion.
One aspect of the present invention relates to a kind of method of making preform.In brief, this method may further comprise the steps.One deck cladding glass particle deposition on the outside surface of cladding glass pipe, and is inserted a plurality of small pieces in the described cladding glass pipe.Have at least an optical characteristics of small pieces to be different from the optical characteristics of adjacent dice in the Glass tubing, and each small pieces have a glass of fiber core central section at least.When applicator assembly is heated to a certain temperature of the sintering temperature that is lower than the cladding glass particle, make a kind of gas flow through pipe along medullary ray.Medullary ray gas be selected from pure chlorine and with a kind of diluent gas blended chlorine.To the applicator assembly heating,, thereby produce radially inner power then, pipe is collapsed on the small pieces and with small pieces fuses, and the cladding glass pipe is vertically shunk, thereby force adjacent dice approaching mutually, and fuse together mutually with the sintering coating.
Another aspect of the present invention relates to a kind of whole optical fiber that is formed by aforesaid method.This optical fiber comprises the fiber segment of a plurality of continuous placements, and each fiber segment has a glass core and a glass surrounding layer.The fibre core of first fiber segment is different from the fibre core of each and first section adjacent fiber segment.The covering of first fiber segment is identical with the covering of adjacent fiber section.Between per two adjacent fiber sections a zone of transition is arranged, its length is less than 10 meters.
Summary of drawings
Fig. 1 shows total dispersion to be changed along waveguide fiber lengths.
It is how zero waveguide fiber changes that Fig. 2 shows chromatic dispersion, can in the presetted wavelength window total dispersion of waveguide be remained in the predetermined scope.
Fig. 3 a is a graphic representation, shows the curve of the power loss of a system to power input, and wherein this system is made of specific waveguide branch length, has very low total dispersion numerical value.
Fig. 3 b is a graphic representation, shows the curve of the power loss of a system to power input, and wherein this system is made of specific waveguide branch length, has higher total dispersion numerical value.
Fig. 4 is the graphic representation of total dispersion to power loss.
Fig. 5 is the graphic representation of dispersion variation Cycle Length to power loss.
Fig. 6 is the graphic representation of transitional region length to power loss.
Fig. 7 is a synoptic diagram, shows the process of making optical fiber, and the adjacent segment in the optical fiber has visibly different characteristic.
Fig. 8 is the amplification view of small pieces among Fig. 7 (tablet).
Fig. 9 shows and apply one deck cladding glass particle on a pipe.
Figure 10 is the fusion assembly sectional view by consolidation/fusion step generation shown in Figure 7.
Figure 11 is the phantom view that Fig. 7 embodiment is revised.
Figure 12 and 13 is refractive index curve of dispersion shifted optical fiber.
Detailed description of the present inventionThe dispersion managed optical fiber design
Fig. 1 shows the relation of DM optical fiber total dispersion to waveguide length.As can be seen, total dispersion on the occasion of 2 and negative value 4 between alternately change.Present the branch length of negative dispersion and the branch length that multistage presents positive dispersion although Fig. 1 shows multistage, only need one section negative dispersion branch length and one section positive dispersion branch length just much of that.Expanded range explanation total dispersion by the total dispersion value of line segment 6 expression changes with propagating light wavelength.The sea line of scope 6 is represented the total dispersion of special optical wavelength.In general, be that the waveguide length 8 of feature is approximately greater than 0.1 km with special total dispersion.Except the numerical value that the requirement that can long-pending by chromatic dispersion (length * corresponding total dispersion) sum equals preset value is released, length 8 does not have the upper limit basically.
Total dispersion shown in Figure 2 to the schematic view illustrating of wavelength the design of DM single mode waveguide optical fiber consider.The total dispersion of straight line 10,12,14 and four independent waveguide fibers of 16 expressions.In the narrow range of wavelengths of considering for every waveguide that is approximately 30 nanometers, chromatic dispersion can be approximate with straight line as shown in the figure.Carry out multiplexed wavelength region and be from 26 to 28 scope.Any waveguide segment that has zero-dispersion wavelength in scope 18 to 20 can make up with the waveguide segment that has a zero-dispersion wavelength in scope 22 to 24, to be formed on the waveguide that has a preliminary election total dispersion in working window 26 and 28.
Following is to carry out on the basis of Fig. 2 for example.Getting working window is 1540 nanometer to 1565 nanometers.Suppose that single mode waveguide CHROMATIC DISPERSION IN FIBER OPTICS slope is about 0.08ps/nm
2-km.Making the value of line segment 30 is 0.5ps/nm-km, and the value of line segment 32 is 4ps/nm-km.Added condition is that the total dispersion in the working window must be in about 0.5 to 4ps/nm-km scope.So simple straight line calculates the zero-dispersion wavelength scope (18 to 20) of 1515 nanometer to 1534 nanometers.Similarly calculate the zero-dispersion wavelength scope of 1570 nanometer to 1590 nanometers.The total dispersion that has the waveguide fiber section of zero chromatic dispersion in to described scope asks algebraic sum will draw the total dispersion that is between 0.5 to 4ps/nm-km.
As shown in Fig. 3 a and Fig. 3 b, the design of DM optical fiber and the details of telecommunication system relation are very big, Fig. 3 a and Fig. 3 b have the power loss of 120 km links of 8 channels to the graphic representation of power input, and wherein the frequency interval of interchannel is 200 GHzs (GHz).In this case, power loss is mainly caused by four-wave mixing.Curve 62 among Fig. 3 a skyrockets when the about 10dBm of power input to losing near 1dB.For curve 64, time loss is about 0.6dB for 10dBm when power input.The size of the total dispersion of these two curves all is about 0.5ps/nm-km.Yet for steeper curve 62, the branch length with total dispersion of given symbol is 10km.Corresponding minute length of the chromatic dispersion of curve 64 is 60km.Extra loss is owing to for short 10km branch length situation, the extra zone of transition of passing through zero chromatic dispersion be arranged.Another kind of saying is that for the 10km situation, the phase splitting of signal (it is proportional to vibration branch length) is big not enough to preventing four-wave mixing basically." vibration branch length " can be positive dispersion branch length or the negative dispersion branch length in the one-period.When not having the symbol relevant, think that positive and negative vibration branch length equates with vibration branch length.
Yet the size of total dispersion is also for phase splitting thereby influential for power loss.Power loss shown in the curve 66 of Fig. 3 b is for such system, and it is identical with the system that is shown in Fig. 3 a, just divides length shorter, about 1km, and the size of total dispersion is 1.5ps/nm-km.The waveguide total dispersion is reduced to less than 0.2dB from 0.6dB from just having reduced power loss significantly to the mobility scale of bearing broad.The power loss difference of about 0.4dB/120km is big must to be enough to become poor between functional link and the NOT-function link (particularly for 500km or the longer no regenerated link of long distance).
Fig. 4 can explain with the mode identical substantially with 3b with Fig. 3 a.Curve 68 shows the graphic representation of power loss for the total dispersion size.The branch length of waveguide is elected as about 1km, because the shortest normally used cable length is about 2km.8 channels are still arranged, and the frequency interval of interchannel is 200GHz, and total length is 120km, and power input is 10dBm.When the size of total dispersion falls to about 1.5ps/nm-km when following, power loss still rises steeper.
In Fig. 5, represent system design from another viewpoint.In this case, chromatic dispersion size stuck-at-.5ps/nm-km.The power loss of the such system of curve 70 representatives is for the graphic representation of minute length scale, and there are 8 channels in this system, and the frequency interval of interchannel is 200GHz, and power input is 10dBm.Length is chosen as 60 chromatic dispersion branch length and allows branch length to change.When minute length when 2km is above, power loss is lower.But, what can not obtain above 2km by prolonging branch length for sizable total dispersion size.When the used number of channel is reduced to 4, note generally speaking paying lower four-wave mixing loss, shown in curve 72.
Another design considers it is the precipitous degree of total dispersion reindexing in the transition length.Here, transition length also influences the signal phase separation.Like this, shallow transition (shallow transition) will make signal propagate near zero waveguide region at total dispersion, and this has disadvantageous effect for the power loss that is produced by four-wave mixing.
Below for example understand the influence of transition length to power loss.Suppose that power input is 10dBm.Adopt four channels, the frequency interval of interchannel is 200GHz.The size of total dispersion is 1.5ps/nm-km, and the vibration branch length of total dispersion is taken as 2km.Shown in curve among Fig. 6 74, power loss shows that to the graphic representation of transition length transition length is preferably short.Optical fiber is made
Fig. 7 and Fig. 8 show the very method of short transitional region of production.In order to carry out this method, available any known prepared fibre core prefabricated rods.For example, the technology that is used for making the fibre core prefabricated rods has OVD (OVD), VAD (VAD), modified chemical vapor deposition (MCVD) and PCVD (Plasma Chemical Vapor Deposition) (PCVD), in modified chemical vapor deposition, in Glass tubing, form core layer, and in PCVD (Plasma Chemical Vapor Deposition), the reaction in the pipe is caused by plasma body.The fibre core prefabricated rods can be made of glass of fiber core fully, perhaps is made of a core region and a clad region.
Two or more initial cylindrical prefabricated rods that forms are arranged, they are added surrounding layer, can form the different optical fiber of optical characteristics.For most applications, only need two kinds of dissimilar fibre core prefabricated rods; In Fig. 7 and embodiment shown in Figure 8, two kinds of prefabricated rods have been used.
Cut first and second prefabricated rods into pieces 81 and 82 respectively.The length of small pieces depends on the particular type of made optical fiber.In the process of making DM optical fiber, select the length of small pieces 81 and 82, so that in last optical fiber, obtain required branch length.Small pieces can add the method that fractures with simple line and make.Small pieces 81 have core region 83 and clad region 84; Small pieces 82 have core region 85 and clad region 86.
Kapillary glass handle 92 with annular augmenting portion 97 is welded to an end of elongated Glass tubing 90.Handle 92 is the 5th, 180, the part of No. 410 spherical joint type airing systems that United States Patent (USP) disclosed.Augmenting portion 97 is suitable for being placed on the pedestal of band slit of supporting tube (not shown), and supporting tube is suspended on handle 92 in the consolidation stove.Heat managing 90, and near handle 92, form pit 98.Another kind method is to make handle 92 and manage 90 adjacent that part of depressions.The assembly that will comprise pipe 90 and handle 97 inserts the lathe (not shown), and makes its relative blowtorch 100 rotation and translations, deposition one deck cladding glass particle or dust 91 (referring to Fig. 9) on pipe 90.Can make coating 91 increase to enough big outside diameter (OD), thereby make last prefabricated rods consolidation and be drawn into optical fiber with required optical characteristics.As shown in Figure 7, layer 91 can topped handle 92.
Be lower than the other end to managing 90 orientations, make an end that is fixed in handle 92, and small pieces 81 and 82 replaced the upper end of tubular stinger 90.Small pieces can not be fallen outside the pit 98.Heat managing 90, and form pit 99 at the other end of relative depression 98.When pipe 90 counter-rotatings, pit 99 can prevent that small pieces from dropping out.
Handle 92 is suspended on the supporting tube (not shown), reduces supporting tube assembly 94 is inserted not (muffle) burner hearth of consolidation horse.When heating component 94 in the consolidation stove, dry gas upwards flows through stove (along arrow 93).Dry gas generally includes chlorine and such as the mixture of rare gas elementes such as helium.The air-flow (along arrow 96) that contains chlorine is from managing 92 inflow pipes 90.Although air-flow 96 can contain such as diluent gass such as helium, preferably pure chlorine can reach the purpose of cleaning.Because each small pieces 81 and 82 diameter are slightly less than the interior diameter of pipe 90, thus chlorine to dirty, be enclosed in each small pieces around; It also flows between adjacent small pieces or diffusion.Then, chlorine is discharged by the bottom of pipe 90.Chlorine plays the thermochemistry sanitising agent.During this hot chlorine clean step, temperature is lower than the melting temperature of dust coating 91, make small pieces 81 and 82 and pipe being spaced apart between 90 carry out required cleaning and open wide the sufficiently long time.At high temperature, the chlorine clean step is more effective.Because at a lower temperature, the extended period of cleaning can be very long, do not wish like this with regard to commercial purpose, so the temperature of cleaning preferably is at least 1000 ℃.Obviously, if do not mind process period, can use lower temperature so.The popular very big benefit of hot chlorine between pipe 90 and small pieces 81 and 82, it can make the surface of adjacent dice and pipe and small pieces lump together, and can not form particle on their opposite face.Particle comprises such as bubble and impurity etc. can produce the defective of decay in finished product optical fiber.
When assembly 94 is further reduced, when stretching in the furnace muffle, the wall that is positioned at that part of pipe 90 of powder bed 91 ends is collapsed and is fused together, thereby blocks the medullary ray of cl gas flow.Then,, can connect a valve, inhale vacuum in 90 managing as an optional step.When assembly 94 continues to move when stretching into furnace muffle, the tip that at first is it is that the remainder of assembly is under the highest furnace temperature that is enough to sintering coating 91 then.When sintering, powder coating 91 radially and vertically shrinks.
When powder coating 91 longitudinally shrank, it made the contraction in length of pipe 90.This forces adjacent dice 81 and 82 to lump together under sintering temperature, thereby fusion does not form particle.Do not do vertical contraction if manage 90, just not fully fusion of adjacent dice forms low-loss optical fiber.
When powder coating 91 radially shrank, it applied a radially inside power to managing 90.This makes inwardly extruding small pieces 81 and 82 of pipe 90, forms one and makes three zones 81,90 ' and 91 ' complete fused fuser assembly 98 (see figure 10)s.Zone 90 ' be the pipe of collapsing, and zone 91 ' be through agglomerating porous coating.The powder that density is quite low provides bigger inside power; But the powder coating must be enough closely knit, in case split.
The step that makes the surrounding layer pipe consolidation of having filled small pieces and obtain not have the particle prefabricated rods is an important procedure of processing.For small pieces are not fused together with having particle, must make cl gas flow cross pipe, clean all surfaces with chemical method.But the step that vacuumizes after the fusion of blank tip not necessarily.
From the consolidation stove, take out fuser assembly.In finished product optical fiber, the zone 90 of fuser assembly 98 ' and 91 ' play a part covering.Assembly 98 can be used as the wire drawing blank, and can be with its direct drawing optic fibre.Before the drawing optical fibers step, can be that fuser assembly 98 increases additional cladding layer selectively.For example, can with one deck covering powder deposition on assembly 98, make its consolidation then.Another kind method is that assembly 98 is inserted in the cladding glass pipe.If the increase additional cladding layer must suitably be regulated the diameter of the core region of small pieces 81 and 82 so.
With before fibre core core material or small pieces are inserted the cladding glass pipe, its interfused method is compared, preparation method of the present invention is simple, and can carry out fusion under the exsiccant environment.This method is adjusted automatically to following process, promptly when pipe 90 is inwardly collapsed during sintered porous glass coating 91, makes on the axle that is centered close to finished product wire drawing blank of the different adjacent fibre core core material of diameter.
Method of the present invention has brought new degree of freedom for the customization optical fiber property.This method can form adjacent area and section has the optical fiber of different performance.Very precipitous transitional region connects adjacent fiber segment.The decay of this optical fiber is identical apart from telecommunication optical fiber with the length of standard, promptly less than 0.25dB/km, and preferably less than 0.22dB/km.
In the embodiment shown in fig. 11, in pipe 90, do not form pit 98 and 99.One section shorter glass capillary 104 is welded to an end of pipe 90.And the ring glass handle and the other end of pipe 90 are fused.Small pieces 81 and 82 are inserted handles and enter in the pipe 90.Because the hole of pipe 104 is quite little, described small pieces can not drop out this pipe.When assembly is descended, enter in the consolidation stove, during the beginning sintering processes, pipe 104 is fusion at first, blocks cl gas flow.Form DM optical fiber
Form a dispersion controlled optical fiber with the many fibre core prefabricated rods that can form single-mode fiber with different zero-dispersion wavelengths.Can change the chromatic dispersion of one section waveguide by changing such as geometric parameter, specific refractory power, index distribution or the one-tenth various waveguide parameters that grade.Thereby any a large amount of refractive index profile for regulate waveguide dispersion for a change total dispersion required handiness is provided.The 4th, 715, No. 679 patents of the U.S. of Bhagavatula have been done discussion to these.
A kind of index distribution type that can be used to be formed on the optical fiber that has zero chromatic dispersion on the predetermined wavelength has suitable high refractive index central zone, be wrapped in the annular region that specific refractory power reduces around the central zone, coated outside high outer region (seeing Figure 12), the last specific refractory power decline zone of refractive index ratio again.The index distribution of another embodiment (seeing Figure 13) comprises a constant substantially and central zone that specific refractory power equates with the cladding glass specific refractory power basically of specific refractory power, and the adjacent annular region that specific refractory power increases.Optical fiber with this type index distribution is made easily.
Simple DM Refractive Index Profile o is the step change type index distribution.Two fibre core prefabricated rods can be made by identical fibre core and clad material, and the radius of a core region is greater than another.The wire drawing blank is pulled into an optical fiber, and the fiber segment with first fiber core radius is dispersed between the fiber segment greater than second radius of first radius.Being approximately 5% to 25% core diameter difference is enough to form the required negative dispersion of just arriving and changes.Generally use for great majority, 5% to 10% change in radius scope is just enough.
Following example has been described the forming process that is suitable for providing in the 1545-1555 nanometer single mode DM optical fiber of zero chromatic dispersion.Make two different fibre core prefabricated rods with being similar to the described method of the 4th, 486, No. 212 patents of the U.S., the content of described patent is included in this by reference.In brief, the method of this patent may further comprise the steps: a) glass particle is deposited on the single mandrel, form the porous glass preform, b) remove axle and make the porous preform consolidation, form an exsiccant through the agglomerating prefabricated rods, c) stretch through the agglomerating prefabricated rods, and make axial aperture closed at this moment.The fibre core prefabricated rods comprises a glass of fiber core central zone, is wrapped in the very thin cladding glass of one deck on every side.Two fibre core prefabricated rods all have fiber core refractive index distribution pattern as shown in figure 12.The first fibre core prefabricated rods is such, is 125 microns single-mode fiber if add top covering and pull into outside diameter to it, and it will present zero chromatic dispersion in 1520 nanometers.The second fibre core prefabricated rods is such, is 125 microns single-mode fiber if be made into outside diameter with similar approach, and its zero-dispersion wavelength will be 1570 nanometers.It is 7 millimeters and 7.1 millimeters that the fibre core prefabricated rods is drawn into diameter.Break through the prefabricated rods line of drawing and with it first and second, form the small pieces 81 and 82 that length equates substantially.Small pieces 81 have core region 83 and clad region 84; Small pieces 82 have core region 85 and clad region 86.
Use one meter long silica tube 90; Its interior diameter (ID) is 7.5 millimeters, and outside diameter (OD) is 9 millimeters.Use technology described in conjunction with Figure 7, small pieces 81 and 82 are packed into manage in 90.Make coating 91 increase to enough big outside diameter, with the prefabricated rods consolidation of gained and to be drawn into outside diameter be 125 microns single-mode fiber.
The assembly 94 of gained is suspended in the consolidation stove.When with 1rpm rotary components 94, it is dropped in the consolidation furnace muffle 95 with the speed of 5 millimeters of per minutes.The mixed gas (along arrow 93) that comprises 50sccm chlorine and 40slpm helium upwards flows through retort furnace.0.3slpm cl gas flow along medullary ray be downward through small pieces 81 and 82 around, and discharge from managing 90 bottom.Top temperature in the consolidation stove is about 1450 ℃.When assembly 94 moves in the burner hearth downwards, clean the surface and the internal surface of managing 90 of small pieces 81 and 82 with chemical mode along the cl gas flow of medullary ray.When assembly 94 further when mobile, is lower than that part of pipe 90 fusings of small pieces in burner hearth, and block the cl gas flow of medullary ray.Connect a valve (not shown) then, will manage in 90 and vacuumize.Assembly 94 continues to move in retort furnace, and sintering coating 91.Pipe 90 is forced to inwardly close small pieces 81 and 82, and the contact surface of all glass elements has all melted.When sintered powder 91, pipe 90 shortens, and forms the fusion connection of no particle between adjacent small pieces.
After from the consolidation stove, taking out the wire drawing blank that forms with this technology, it is stretched, the formation outside diameter is 125 microns a DM optical fiber.Drawn the fine single mode DM optical fiber made from this technology; Decay is generally 0.21dB/km.This decay with add surrounding layer by fibre core core material to one 7 millimeters, form a prefabricated rods, again by preform bar stretching go out decling phase that dispersion shifted single mode fiber presents with.Two kinds of dissimilar small pieces that adopt in the optical fiber have merged technological process, and zero chromatic dispersion is provided on the 1545-1555 nano wave length.Thereby, can change the zero-dispersion wavelength of optical fiber by change the ratio of every kind of fibre core length in the optical fiber in optical fiber one an end intercepting part.
Vibration divides wavelength and cycle to be controlled by the length of fibre core prefabricated rods small pieces.Having drawn vibration branch length is the optical fiber of 1.2-2.5km.Other fiber type
Specifically described method of the present invention, and described a kind of method of making this optical fiber with an aforementioned concrete example in conjunction with the manufacturing of DM single-mode fiber.But this method can be used to make the optical fiber of the optical property of many other types along the fiber lengths system change.In each case, by suitable small pieces are inserted pipe and process this pipe as mentioned above, just can be made into optical fiber.
Present visibly different alternately fiber segment for optical fiber provides the Δ value, can make spontaneous brillouin scattering (SBS) minimum, wherein Δ is defined as (n
1 2-n
2 2)/2n
1 2(n
1And n
2Be respectively the specific refractory power of fibre core and covering).One type small pieces that are used for making preform present a given Δ, and the small pieces of another kind of type present visibly different Δ value.The Δ value of fibre core can be controlled by the amount of doping agent in the control fibre core or by the composition (being about to other doping agent is added in the fibre core) that changes fibre core.In order to change specific refractory power or, can to use multiple doping agents such as comprising titanium oxide, aluminum oxide and boron oxide such as other character such as viscosity.By in pipe, alternately placing a plurality of small pieces and a plurality of small pieces that can form the optical fiber that does not filter of standard that can form optical fiber, can make the optical fiber that optical filtering power can be provided with filtering functions.
The length of small pieces needn't equate or approaching equating.For example, optical fiber can comprise the part that some are quite short, and its fibre core active dopant ion that mixed when carrying out pumping with suitable wavelengths light, can produce the stimulated emission of light.Be particularly suitable for this purpose such as rear-earth-doped ions such as erbiums.Therefore, do not have bait fibre core small pieces and quite short er-doped fibre core small pieces, can make er-doped fibre core section along the spaced apart optical fiber of fiber lengths by using quite long standard.
By with (wherein the core diameter of each small pieces is less than the core diameter of the diameter of last small pieces or each small pieces diameter greater than last small pieces) in a plurality of small pieces tubular stingers, can make the optical fiber that dwindles methodically such as the fibre core size of in Soliton optical fiber, using.Another kind method is that the meeting that changes small pieces influences some other fibre core feature of chromatic dispersion, and the finished product CHROMATIC DISPERSION IN FIBER OPTICS is descended to the other end is dull from an end of optical fiber.
The above-mentioned different small pieces of alternately placing of optical property that used for example.So form single prefabricated rods.Make its fiber core refractive index asymmetric on the orientation.For example, can make fibre core not too round, promptly the cross-sectional shape of fibre core is the ellipse (seeing the 5th, 149, No. 349 patents of the U.S.) with main shaft and countershaft.Another kind of situation is, as United States Patent (USP) the 5th, 152, No. 818 described, and in the relative both sides of fibre core, optical fiber comprises stress rods (stress rod).Oval doped core optical fiber can form like this.Prefabricated rods is cut into pieces.For the cladding glass pipe adds one deck cladding glass powder.Small pieces are inserted in the cladding glass pipe, make the main axis rotation of the relative adjacent dice fibre core of main shaft of the oval fibre core of small pieces.With the consolidation of covering powder and make small pieces and pipe and small pieces between after the fusion, the wire drawing blank of gained is pulled into the lower optical fiber of polarization mode dispersion.
Although gone through specific embodiments of the present invention, the present invention only is subjected to the restriction of following claims.
Claims (46)
1. a method of making preform is characterized in that, may further comprise the steps:
With one deck cladding glass particle deposition on the outside surface of cladding glass pipe with first and second ends;
A plurality of small pieces are inserted in the described cladding glass pipe, have at least at least one guide properties of described small pieces to comprise positive total dispersion in the described cladding glass pipe, the guide properties of one adjacent dice comprises negative total dispersion, and each small pieces has a glass of fiber core central section at least;
Applicator assembly is heated to a certain temperature, and this temperature is lower than the sintering temperature of described cladding glass particle;
Make a kind of gas flow through described pipe along medullary ray, described gas be selected from pure chlorine and with a kind of diluent gas blended chlorine, then
To the applicator assembly heating,, thereby produce radially inner power with the described coating of sintering, described pipe is collapsed on the described small pieces and with small pieces to fuse, and described cladding glass pipe is vertically shunk, thereby force adjacent dice approaching mutually, and fuse together mutually.
2. the method for claim 1 is characterized in that, each described small pieces comprises one and is wrapped in described central core glass region clad region on every side.
3. method as claimed in claim 2 is characterized in that, has at least two adjacent dice to have the fibre core of oval cross-section in the described cladding glass pipe, the main shaft misalignment of the fibre core of described at least two adjacent dice.
4. the method for claim 1 is characterized in that, described chlorine comprises the gas of being made up of pure chlorine.
5. the method for claim 1 is characterized in that, described chlorine contained gas is made up of chlorine and a kind of diluent gas.
6. the method for claim 1 is characterized in that, during the step that described cladding glass pipe is collapsed on the described small pieces, medullary ray gas flow step continues, until the remollescent glass component is collapsed till its disconnection.
7. method as claimed in claim 6, it is characterized in that, a zone that makes close its second end of described cladding glass pipe is to internal strain, and during the step that described cladding glass pipe is collapsed on the described small pieces, medullary ray gas continues to flow, until described cladding glass pipe is collapsed till its disconnection.
8. method as claimed in claim 6, it is characterized in that, with second end fusion that prolongs pipe and described cladding glass pipe, and during the step that described cladding glass pipe is collapsed on the described small pieces, medullary ray gas continues to flow, until described prolongation pipe is collapsed till its disconnection.
9. the method for claim 1, it is characterized in that, after being collapsed to described cladding glass pipe on the described small pieces, described first end of described medullary ray gas from described cladding glass pipe disconnected, a vacuum source is linked to each other with second end of described cladding glass pipe.
10. the method for claim 1 is characterized in that, has the index distribution of small pieces different with the index distribution of adjacent dice in the described small pieces.
11. the method for claim 1 is characterized in that, the core region of at least the first small pieces comprises the doping agent that can amplify light in the described small pieces, and has at least small pieces adjacent with first small pieces not contain described doping agent.
12. a method of making optical fiber is characterized in that, may further comprise the steps:
With one deck cladding glass particle deposition on the outside surface of cladding glass pipe with first and second ends;
A plurality of small pieces are inserted in the described cladding glass pipe, have at least at least one guide properties of described small pieces to comprise positive total dispersion in the described cladding glass pipe, and the guide properties of an adjacent dice comprises negative total dispersion, and each small pieces has a glass of fiber core central section at least;
Applicator assembly is heated to a certain temperature, and this temperature is lower than the sintering temperature of described cladding glass particle;
Make a kind of gas flow through described pipe along medullary ray, described gas be selected from pure chlorine and with a kind of diluent gas blended chlorine, then
Applicator assembly is heated, with the described coating of sintering, thereby produce radially inner power, described pipe is collapsed on the described small pieces and with small pieces to fuse, and described cladding glass pipe is vertically shunk, thereby force adjacent dice approaching mutually, and fuse together mutually, form one through the agglomerating prefabricated rods, and
Form an optical fiber by described through the agglomerating prefabricated rods, described optical fiber comprises a plurality of vertical section, and every section corresponding with small pieces in the described small pieces.
13. method as claimed in claim 12 is characterized in that, the core region of each described small pieces is different with the core region of each residue small pieces in the described small pieces in the described cladding glass pipe.
14. method as claimed in claim 13 is characterized in that, the optical characteristics of described small pieces is such, when from an end of described optical fiber when its other end is analyzed described section, the chromatic dispersion of described each section of optical fiber is lower than the chromatic dispersion of adjacent segment.
15. method as claimed in claim 12 is characterized in that, the optical characteristics of described small pieces is such, and the Δ value of described each section of optical fiber is different from the Δ value of adjacent fiber section, wherein Δ=(n
1 2-n
2 2)/2n
1 2, and n
1And n
2It is respectively the specific refractory power of the fibre core and the covering of described optical fiber.
16. method as claimed in claim 12, it is characterized in that, the optical characteristics of described small pieces is such, at least the first section light of propagating a certain setted wavelength in the described fiber segment, and have one section light with described first section adjacent described setted wavelength of fiber segment filtering at least.
17. a method of making optical fiber is characterized in that, may further comprise the steps:
First group of a plurality of cylindrical fibre core small pieces is provided, and each small pieces in described first group of a plurality of small pieces have a glass of fiber core central section at least;
Second group of a plurality of cylindrical fibre core small pieces is provided, each small pieces in described second group of a plurality of small pieces have a glass of fiber core central section at least, the radial refractive index distribution of described second group of a plurality of small pieces is different from the radial refractive index distribution of described first group of a plurality of small pieces, the guide properties of described first group of a plurality of small pieces comprises positive total dispersion, and the guide properties of described second group of a plurality of small pieces comprises negative total dispersion;
One deck glass particle is deposited on the outside surface of cladding glass pipe;
First and second groups of a plurality of small pieces are alternately inserted in the described cladding glass pipe;
Make a kind of gas flow into first end of described cladding glass pipe along medullary ray, flow between described pipe and described small pieces and between the adjacent dice, and flow out second end of described pipe, described medullary ray gas be selected from pure chlorine and with a kind of diluent gas blended chlorine, then
Applicator assembly is heated, with the described coating of sintering, thereby produce radially inner power, described pipe is collapsed on the described small pieces and with small pieces to fuse, and described cladding glass pipe is vertically shunk, thereby force adjacent dice approaching mutually, and fuse together mutually, form one through the agglomerating prefabricated rods, and
Form an optical fiber by described through the agglomerating prefabricated rods, described optical fiber comprises a plurality of vertical section, and every section corresponding with small pieces in the described small pieces.
18. method as claimed in claim 17, it is characterized in that, the optical characteristics of described small pieces is such, those fiber segments corresponding with described first group of a plurality of small pieces are presented to fixed chromatic dispersion in a given light wave strong point, and present second chromatic dispersion different with described given chromatic dispersion with corresponding those fiber segments of described second group of a plurality of small pieces in described given light wave strong point, thereby the chromatic dispersion of described optical fiber at described setted wavelength place is a numerical value between described given chromatic dispersion and described second chromatic dispersion.
19. a whole optical fiber is characterized in that, comprising:
The fiber segment that a plurality of serials are placed, each fiber segment has a glass core and a glass surrounding layer, the fibre core of first fiber segment is different from the fibre core of each and described first section adjacent fiber segment, the covering of described first fiber segment is identical with the covering of described adjacent fiber section, the guide properties of described first fiber segment comprises positive total dispersion, and the guide properties of described adjacent fiber section comprises negative total dispersion; With
A zone of transition, this zone is between per two adjacent fiber sections, and the length of described zone of transition is less than 10 meters.
20. optical fiber as claimed in claim 19, it is characterized in that, the index distribution of each fiber segment fibre core is asymmetric on the orientation, has an axle that constitutes by largest refractive index, the largest refractive index axle of at least one fiber segment described in the described adjacent fiber section of largest refractive index axle misalignment of described first fiber segment.
21. optical fiber as claimed in claim 19, it is characterized in that, the fibre core of at least one fiber segment is oval-shaped in the fibre core of described first fiber segment and the described adjacent fiber section, the main shaft of the oval fibre core of at least one fiber segment described in the described adjacent fiber section of main shaft misalignment of the oval fibre core of described first fiber segment.
22. optical fiber as claimed in claim 19 is characterized in that, the index distribution of described first fiber segment is different from the index distribution of described adjacent fiber section fibre core.
23. optical fiber as claimed in claim 19 is characterized in that, the Δ value of described first fiber segment is different from the Δ value of described adjacent fiber section, wherein Δ=(n
1 2-n
2 2)/2n
1 2, and n
1Be the largest refractive index of fiber core, and n
2It is the specific refractory power of fibre cladding.
24. optical fiber as claimed in claim 19 is characterized in that, the composition difference of described first fiber segment and the fibre core composition of described adjacent fiber section.
25. optical fiber as claimed in claim 19 is characterized in that, the fibre core of described first fiber segment comprises a kind of doping agent that can amplify light, and described adjacent fiber section does not contain described doping agent.
26. optical fiber as claimed in claim 19 is characterized in that, the optical characteristics of described fiber segment is such, when from an end of described whole optical fiber when its other end is analyzed described section, the chromatic dispersion of every section described fiber segment is lower than the chromatic dispersion of adjacent segment.
27. optical fiber as claimed in claim 19 is characterized in that, the light of the described first fiber segment filtering, one setted wavelength, and described adjacent fiber section is propagated the light of described setted wavelength.
28. optical fiber as claimed in claim 19, it is characterized in that, described first fiber segment is presented to fixed chromatic dispersion in a given light wave strong point, and described adjacent fiber section presents second chromatic dispersion different with described given chromatic dispersion in described given light wave strong point, thereby the chromatic dispersion of described optical fiber at described setted wavelength place is a numerical value between described given chromatic dispersion and described second chromatic dispersion.
29. optical fiber as claimed in claim 19 is characterized in that, the decay of described whole optical fiber is less than 0.25dB/km.
30. optical fiber as claimed in claim 19 is characterized in that, the decay of described whole optical fiber is less than 0.22dB/km.
31. the single-mode fiber of a dispersion controlled system is characterized in that, comprising:
One glass of fiber core district, it is made of a plurality of small pieces adjacent one another are in the silica tube, have at least small pieces to have first guide properties in described a plurality of small pieces, and have at least small pieces to have second guide properties that is different from described first guide properties, first guide properties comprises positive total dispersion, second guide properties comprises negative total dispersion, and described small pieces are made by the glass particle depositing technics; With
One cladding glass district, it is centered around around the described glass of fiber core district.
32. optical fiber as claimed in claim 31 is characterized in that, the optical attenuator of described optical fiber is less than about 0.25dB/km.
33. optical fiber as claimed in claim 31 is characterized in that, each in described a plurality of small pieces comprises that a chromatic dispersion is long-pending, and the long-pending algebraic sum of chromatic dispersion is essentially zero.
34. optical fiber as claimed in claim 31 is characterized in that, described positive total dispersion and described negative total dispersion are changed to 20ps/nm-km from 0.5ps/nm-km in a predetermined waveguide scope.
35. optical fiber as claimed in claim 34 is characterized in that, described presetted wavelength scope arrives between about 1570 nanometers in about 1520 nanometers.
36. optical fiber as claimed in claim 31 is characterized in that, described a plurality of small pieces comprise a plurality of small pieces with positive total dispersion and a plurality of small pieces with negative total dispersion, and described a plurality of small pieces the relative position of each other makes it positive and negative alternately.
37. optical fiber as claimed in claim 36 is characterized in that, the described a plurality of small pieces with positive total dispersion are made by different prefabricated components with the described a plurality of small pieces with negative total dispersion.
38. optical fiber as claimed in claim 31 is characterized in that, described a plurality of small pieces comprise that a glass of fiber core central section and one are wrapped in the cladding glass district around the described glass of fiber core central section.
39. optical fiber as claimed in claim 31 is characterized in that, the optical attenuator of described optical fiber is less than 0.25dB/km.
40. optical fiber as claimed in claim 31 is characterized in that, the optical attenuator of described optical fiber is less than 0.22dB/km.
41. the manufacture method of the single-mode fiber of a dispersion controlled system is characterized in that, may further comprise the steps:
In a Glass tubing, place a plurality of small pieces made from the glass particle depositing technics, make it adjacent one another are, have at least small pieces to have first guide properties in described a plurality of small pieces, and have at least small pieces to have second guide properties that is different from described first guide properties, described first guide properties comprises positive total dispersion, and second guide properties comprises negative total dispersion;
Described a plurality of small pieces and described Glass tubing are heated to a certain temperature, and this temperature is enough to make described a plurality of small pieces and described Glass tubing to be fused together and consolidation becomes a prefabricated rods; And
Described prefabricated stick drawn wire is become an optical fiber.
42. method as claimed in claim 41 is characterized in that, described placement step comprise the steps: promptly adjacent to described at least one have the small pieces of second guide properties, alternately insert described at least one have the small pieces of first guide properties.
43. method as claimed in claim 41, it is characterized in that, described a plurality of small pieces comprise a plurality of small pieces with positive total dispersion and a plurality of small pieces with negative total dispersion, and described placement step is included in and alternately inserts described a plurality of small pieces and described a plurality of small pieces with negative total dispersion with positive total dispersion in the described Glass tubing.
44. method as claimed in claim 41, it is characterized in that, in described a plurality of small pieces each comprises that all a glass of fiber core central section and one are wrapped in the cladding glass district around the described glass of fiber core central section, and described placement step comprises with quartzy particle and is wrapped in step outside the described pipe.
45. method as claimed in claim 41, it is characterized in that, described heating steps comprises crosses between described Glass tubing and the described a plurality of small pieces a kind of gas stream, and described gas is selected from the group that following material is formed: the mixture of chlorine or chlorine and a kind of diluent gas.
46. method as claimed in claim 45 is characterized in that, described heating steps also is included in described gas stream and crosses after the step, produces vacuum in described Glass tubing.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US1643596P | 1996-04-29 | 1996-04-29 | |
| US60/016,435 | 1996-04-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1189812A CN1189812A (en) | 1998-08-05 |
| CN1109661C true CN1109661C (en) | 2003-05-28 |
Family
ID=21777120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97190447A Expired - Fee Related CN1109661C (en) | 1996-04-29 | 1997-04-21 | Method of making optical fibers |
Country Status (10)
| Country | Link |
|---|---|
| EP (1) | EP0835227A4 (en) |
| JP (1) | JP3534192B2 (en) |
| KR (1) | KR19990028560A (en) |
| CN (1) | CN1109661C (en) |
| AU (1) | AU733718C (en) |
| BR (1) | BR9702176A (en) |
| CA (1) | CA2220416A1 (en) |
| RU (1) | RU2169710C2 (en) |
| TW (1) | TW342457B (en) |
| WO (1) | WO1997041076A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6640038B2 (en) | 2000-05-31 | 2003-10-28 | Corning Incorporated | Dispersion managed fibers having reduced sensitivity to manufacturing variabilities |
| JP2005263555A (en) * | 2004-03-18 | 2005-09-29 | Shin Etsu Chem Co Ltd | Method of manufacturing porous glass preform and glass preform for optical fiber |
| CN1300023C (en) * | 2004-08-16 | 2007-02-14 | 华南理工大学 | Method for preparing glass optical fiber prefabricated stick |
| JP5250630B2 (en) | 2008-12-19 | 2013-07-31 | 株式会社フジクラ | Optical fiber preform manufacturing method |
| WO2010119696A1 (en) | 2009-04-16 | 2010-10-21 | 株式会社フジクラ | Method for manufacturing optical fiber wire |
| RU2537450C1 (en) * | 2013-09-27 | 2015-01-10 | Российская Федерация, от имени которой выступает Министерство промышленности и торговли Российской Федерации (Минпромторг России) | Method of manufacturing workpieces for opticasing on nitrogen-doped quartz glass |
| RU2552279C1 (en) * | 2014-02-25 | 2015-06-10 | Федеральное государственное бюджетное учреждение науки Институт радиотехники и электроники им. В.А. Котельникова Российской академии наук | Method of producing optical fibre with elliptical core |
| RU2647207C1 (en) * | 2016-12-23 | 2018-03-14 | Федеральное государственное бюджетное образовательное учреждение высшего образования - Российский химико-технологический университет имени Д.И. Менделеева (РХТУ им. Д.И. Менделеева) | Method for producing a single-mode waveguide |
| CN108254827B (en) * | 2018-01-16 | 2021-05-04 | 江苏睿赛光电科技有限公司 | Active and passive integrated optical fiber and preparation method thereof |
| CN110455320B (en) * | 2019-08-07 | 2021-06-01 | 深圳大学 | Optical fiber sensor and manufacturing method thereof |
| CN113121104B (en) * | 2019-12-31 | 2024-06-25 | 武汉光谷长盈通计量有限公司 | Optical fiber preform and method for preparing optical fiber preform and optical fiber |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1448080A (en) * | 1975-04-10 | 1976-09-02 | Standard Telephones Cables Ltd | Optical fibre transducer |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4212660A (en) * | 1979-03-22 | 1980-07-15 | Corning Glass Works | Method for making multiple mode waveguide having cylindrical perturbations |
| JPS55158146A (en) * | 1979-05-29 | 1980-12-09 | Fujitsu Ltd | Manufacture of optical fiber |
| JPH0316930A (en) * | 1989-06-13 | 1991-01-24 | Fujikura Ltd | Production of optical fiber having complicate refractive index distribution |
| FR2707285B1 (en) * | 1993-07-06 | 1995-08-11 | Alcatel Fibres Optiques | Preform for optical fiber, process for manufacturing such a preform and optical fiber obtained from this preform. |
| CA2161939A1 (en) * | 1994-12-20 | 1996-06-21 | George E. Berkey | Method of making optical fiber having depressed index core region |
| AU693329B2 (en) * | 1995-04-13 | 1998-06-25 | Corning Incorporated | Dispersion managed optical waveguide |
-
1997
- 1997-04-18 TW TW086105324A patent/TW342457B/en active
- 1997-04-21 JP JP53904197A patent/JP3534192B2/en not_active Expired - Fee Related
- 1997-04-21 CN CN97190447A patent/CN1109661C/en not_active Expired - Fee Related
- 1997-04-21 BR BR9702176A patent/BR9702176A/en unknown
- 1997-04-21 EP EP97927608A patent/EP0835227A4/en not_active Withdrawn
- 1997-04-21 RU RU98101508/03A patent/RU2169710C2/en active
- 1997-04-21 CA CA002220416A patent/CA2220416A1/en not_active Abandoned
- 1997-04-21 AU AU32036/97A patent/AU733718C/en not_active Ceased
- 1997-04-21 KR KR1019970709880A patent/KR19990028560A/en active IP Right Grant
- 1997-04-21 WO PCT/US1997/006924 patent/WO1997041076A1/en active IP Right Grant
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1448080A (en) * | 1975-04-10 | 1976-09-02 | Standard Telephones Cables Ltd | Optical fibre transducer |
Also Published As
| Publication number | Publication date |
|---|---|
| RU2169710C2 (en) | 2001-06-27 |
| CN1189812A (en) | 1998-08-05 |
| JP3534192B2 (en) | 2004-06-07 |
| KR19990028560A (en) | 1999-04-15 |
| AU733718C (en) | 2003-03-20 |
| EP0835227A4 (en) | 1998-08-19 |
| AU3203697A (en) | 1997-11-19 |
| CA2220416A1 (en) | 1997-11-06 |
| BR9702176A (en) | 1999-03-02 |
| EP0835227A1 (en) | 1998-04-15 |
| AU733718B2 (en) | 2001-05-24 |
| JPH11513968A (en) | 1999-11-30 |
| TW342457B (en) | 1998-10-11 |
| WO1997041076A1 (en) | 1997-11-06 |
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