CA1236966A - Method of manufacturing a solid preform for drawing optical fibres - Google Patents
Method of manufacturing a solid preform for drawing optical fibresInfo
- Publication number
- CA1236966A CA1236966A CA000447737A CA447737A CA1236966A CA 1236966 A CA1236966 A CA 1236966A CA 000447737 A CA000447737 A CA 000447737A CA 447737 A CA447737 A CA 447737A CA 1236966 A CA1236966 A CA 1236966A
- Authority
- CA
- Canada
- Prior art keywords
- duct
- preform
- oxygen
- fluorine
- manufacturing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- 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
- C03B37/01861—Means for changing or stabilising the diameter or form of tubes or rods
- C03B37/01869—Collapsing
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C15/00—Surface treatment of glass, not in the form of fibres or filaments, by etching
-
- 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
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S65/00—Glass manufacturing
- Y10S65/15—Nonoxygen containing chalogenides
- Y10S65/16—Optical filament or fiber treatment with fluorine or incorporating fluorine in final product
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Geochemistry & Mineralogy (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Glass Compositions (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Glass Melting And Manufacturing (AREA)
Abstract
Abstract.
Method of manufacturing a solid preform for drawing optical fibres.
Upon closing the central duct in hollow preforms an etchant consisting of a mixture of oxygen and a fluorocarbon compound from the group C2F6, C3F8 and n-C4F10 is passed through the duct. In particular of the etchant is passed through the duct only when its diameter is 1 mm or smaller, it is possible to manufacture solid preforms and optical fibres therefrom without a central dip in the refractive index profile.
Method of manufacturing a solid preform for drawing optical fibres.
Upon closing the central duct in hollow preforms an etchant consisting of a mixture of oxygen and a fluorocarbon compound from the group C2F6, C3F8 and n-C4F10 is passed through the duct. In particular of the etchant is passed through the duct only when its diameter is 1 mm or smaller, it is possible to manufacture solid preforms and optical fibres therefrom without a central dip in the refractive index profile.
Description
a~3~
Pi 10.S03 l 10.01.198 Me-thod of manufacturing a solid preform for drawing optieal Elbre.s.
The invention relates to a method of manufacturlng a solid preform for drawing optical fires, in which method a preform, comprising a central duct extending in the longitudinal direetion and wherein at least the part of the preform ~ol1n~incrthe duct consists of quartz glass doped with a dopant which is more volatile than siliea is heated, while passing a f]uorine-eontaining gaseous etchant throuqh -the duct,to a temperature at which the duet star-ts closing spontaneo~ls-ly so as to form a solid preform of the sane length as the hollow preform.
Preforms which eomprise a central duct extendinq in the longitudinal direetion oecur as intermediate products in various - processes for n~¢lufacturing optical fibres. As an exarnple may ke mentioned a process in which vitreous particles are cleposited on a mandril until the desired quanti-ty oE material has keen deposited, after which the mardril is re~ovecl. In other processes (~VD, PCVD) quar-tz glass -tubes are eoated in-ternally with vitreous ma-terial. In this case also, hollow preforms are ohtained.
Nowadays i-t is common practice to close the clue-t extending in the longi-tudinal direc-tion in a separa-te manufacturincJ step kefore starting to draw the fibre. This presents important advantages over proeesses in which fibres are drawn diree-tly from hollow preforms.
Solid preforms ean ye stored, for example, for a longer period of time without the inner par-t whieh is destined for the light transport, being polluted by the atmosphere.
then elosing the central duct the proceclure is, for example, as follo~is. A heating produeed, Eor example, by a k~lrner, is recipro-catecl at a ~mifonn speed along the rotating preform. Uncler the influ-enee of the surfaee tension of the preEorm material, the dicl~eter of the duet gradually deereases mill -the duct closes entirely on passing the heating zone for the last time. This ~ethocl is used in particular in closing hollow preforms obtainecl by jeans of an RID or PCVD process. In the case of porous preforms which are con-strueted from vltreous particles, the duct eloses durinq the consoli-~7q3 ~7~7Pl~ 10.603 2 10.01.1984 dation or vitrifieation of the par-ticles.
A generally used dopant in -the manufac-ture of optical fibres from c~lartz glass is germanium dioxide (Ge~2). During eo]lap-sing of preforms comprising a central duct in which at least the part of the preform which directly adjoins the duet eonsists o-E quar-tz glass clc)ped wi-th a eomparatively volatile clopant, for example, germa-nium dioxide, a part of the dopant may evaporate. This results in a disturbanee of the refraetive index profile. In this case the dif-fusion of the dopan-t from parts of the preform situated fur-ther aT.A7ay from the central duet also plays a part. Ihe profile disturbarlee has an adverse influenee on the bandwidth of the optieal fibre.
It has already teen suggested to reduce the profile disturbanee by leading a fluorine-eontaining gaseous e-tehant -through the central duct during the collapsing of the hollow preform. The gaseous etchant reacts with a layer adjoining the duet and ,7hich has been depleted of dopant by evaporation, while forming gaseous etching products (see, for example, GB 2,084,988 A and FR 2,504,514). As a gaseous etchant are mentioned mix-tures of oxygerl and diehlorodifluoro-nethane (CCl2F2), sulph~lr hexaf]uoride (SF6), earbon te-trafluoricle (CF4), -trichloromonofluoromethane (CCl3F) and nonoehlorotrifluoro-nethane (CClF3).
I-t has been found in practice tha-t -the said compounAs do not glve satisfae-tory resul-ts. It has beerl fo~mcl that the disturbanee of -the refrac-tive index profile can be reclueed, but it canno-t be avoidecl.
For tha-t purpose, for example, reference may be made to -the Fic~lre in the above-cited French Patent Applica-tion 2,504,514 and -the pertaining part of the speeifieation.
It is an objeet of the invention to entirely avoid any disturbanee of the refractive index profile. It has teen fo~md -that this objeet ean be aehieved by means of a method which is characterizecl in that the f]uorine-eontaining etehant which durinq closing is passed through the central duct consists of a mix-hlre of oxygen and one or more gaseous fluorocarbon compo~md(s), selectee from the group eon-sisting of hexafluoroethane (C2F6), octaf~uoropropane (C3F8) ancl cleea-fluoro-n-butane (n-C~F10). By using the said eompolmc1(s) it is achievecl that the available fluorine concentration per s-tanAarA unit of volume is essentially larger, in a manner ~7hich is Aecisive of the ou-tcome of the etching process, -than with the so fclr sugcrestel compounds a Pi 10.G~3 3 10.01.198 including the already previously suggested SF6. Although SF6 per s-tanclard unit of voile ccmprises an octal amoun-t of f]uorine as, for example, C2F6, it has been -found in prac-tice -that at -the collapsing -temperatures used the quan-tity of SiO2 etched-away does not corres-pond to the theoretically calculated c~lantity on the basis of thec~lantity of available SF6. The incomplete reaction in~les the control of the etching process and the reproducibility is bad. This is not the case with, for example, C2F6, since its fluorine conten-t is obviously used completely. The compounds C3F8 and C4F10 have a still higher 0 fluorine c~lantity in standard conditions.
When the said fluorine compounds are used, the fluorine js presented in a more concentrated form so that a smaller supply (volume of gas which is supplied per unit time) will suffice than is the case with compounds which comprise 1ess fluorine err molecule. The etching process may now ke carried out in the last stage of the collapsing process. The inner surface of the duct then is so much smaller that the evaporation of dopant only plays a minor role.
The quantity of evaporating dopant is proportional to the surface area.
It has consequently been found that it is possible when hexafluoroethane is used to completely remove the so-calleil dip in the refractive index profile of gradient index fibres. The qaseous etchant preferably comprises 5-30 vol.O C2F6, the remaincler beinq oxygen. The pressure cluring passing-through -the etchant may at most OR fat to -the pressure of the ambient atn~sphere. rrhe gas supply during the collapsincJ process may be 50 to 60 sccm.PreEerab]y, oxygen is passed -throuyh the cen-tral duct in -the firs-t staqe of the collap--sing process until the diameter of the cluct has clecreasecl until it is a-t rr,os-t 1 rnm the fluorine-con-taining etchant is then passec1-throuqh the duct and -the duct is closed. I~hen etchants cure used in which the fluorine is presented in a concentrated forrn, sr~ll quantities of etchant will suffice. The actual etching -takes place in the very last stage of closing the cluct. Since the inner surface is then small, the quantity of dopant evaporated from the doped layer eYposed during etching is proportionally small.
The invention will now be describecl in greater detail with reference to a n~unber of examples and the accompanyinq draying in which Fiy. 1 shows the refractive incle~Y profile of an optical Pit 10.G03 4 10.01.1984 fibre drawn from a non-etched preform;
Fig. 2 shows the refractive index proEile of an optical fibre drawn from a preform etched with CF4 according to E'rench ` Paten-t Application 2,504,514;
Fig. 3 shows the refrac-tive index profile of an op-tical fibre drawn from a preform etched with C2F6 according to the invention;
Fig. 4 shows the clepenclence of the attenua-tion on the wavelength for optical fibres which are clrawn from a non-etched preform (curve A) and from a preform etched with C2F6 (curve B); and Fig. 5 shows the refractive index profile of an etched preform determined with a so-called preform analyser.
The experiments to be described hereinafter were carried out with a ~uar-tz glass -tube(~eralux') having an outside diameter of 21 mm and an inside diameter of 17 mm and which was coatecl inter-nally with a layer having a thickness of 450 /um built up from 900 sub-layerseach having a thickness of 0,5 /um. The ]ayer showed a varying refractive index. The layer consisted of c~uartz glass dopecl with an increasing quantity of germanium dioxide. The layer was provided by Hans of a non-isothermal plasma cleposition process such as -that described in US-RE 30635- Collapsing too place k~ reciprocating a burner past the rotating tuke.
E'ig. 1 sho~7s the reEractive index profile oE an optical fibre obtained by drawing a preEorm into a fibre havincJ a clkY~e-ter of 125 /um. The width oE the clip a-t the level x is 4.~6 of dis-tance En. The depth of t'he dip is 78.5~ of the clistance Erom the peak oE
the curve to the point y.
Fig. 2 shows the influence of etching of a preform with CF4, as described in French Paten-t Application 2,504,514, on the refractive index profi]e. The depth of the dip after etching is still half the depth of the dip if no etching is carried out(curve wi-thout etching, curve B with etching).
Fig. 3 sho~7s the refractive index profile of an optical fibre obtained by drawing from a preform e-tchecl according to the invention. For that purpose, oxyqen was first led -through the central duct during the moving of the burner past the tube, The supply of oxygen gas was reduced propor-tionally with the decrease of the dic~eter of the cen-tral duct. it -the instcmt the inside cliameter is approxin~lte-ly 1 mm, C2F6 is added -to -the oxygen. The gas mixture now has the com-if 10.G03 5 10.01.198~
position ~8 scem 2 -I 10 scem C2F6. It appears from Fig. 3 that -there is no dip in the refractive index profile of the finished fire.
Fiq. 4 shows two curves which indicate the dependence of the attemlation of the transported light signal on the wavelencJ-th.
Curve A re~a-tes to a fibre obtained from a non-etched preform. Curve relates -to a fibre obtainecl according -to the invention. It has heen found that the so-callecl water peak at 1380 mm is significant]y redueecl by e-tehing wi-th C2F6.
Fig. 5 shows the refrac-tive index profi]e in apreform.
o From this it appears tha-t due to the e-tching with C2F6 the so-called dip in a preform is absent.
Pi 10.S03 l 10.01.198 Me-thod of manufacturing a solid preform for drawing optieal Elbre.s.
The invention relates to a method of manufacturlng a solid preform for drawing optical fires, in which method a preform, comprising a central duct extending in the longitudinal direetion and wherein at least the part of the preform ~ol1n~incrthe duct consists of quartz glass doped with a dopant which is more volatile than siliea is heated, while passing a f]uorine-eontaining gaseous etchant throuqh -the duct,to a temperature at which the duet star-ts closing spontaneo~ls-ly so as to form a solid preform of the sane length as the hollow preform.
Preforms which eomprise a central duct extendinq in the longitudinal direetion oecur as intermediate products in various - processes for n~¢lufacturing optical fibres. As an exarnple may ke mentioned a process in which vitreous particles are cleposited on a mandril until the desired quanti-ty oE material has keen deposited, after which the mardril is re~ovecl. In other processes (~VD, PCVD) quar-tz glass -tubes are eoated in-ternally with vitreous ma-terial. In this case also, hollow preforms are ohtained.
Nowadays i-t is common practice to close the clue-t extending in the longi-tudinal direc-tion in a separa-te manufacturincJ step kefore starting to draw the fibre. This presents important advantages over proeesses in which fibres are drawn diree-tly from hollow preforms.
Solid preforms ean ye stored, for example, for a longer period of time without the inner par-t whieh is destined for the light transport, being polluted by the atmosphere.
then elosing the central duct the proceclure is, for example, as follo~is. A heating produeed, Eor example, by a k~lrner, is recipro-catecl at a ~mifonn speed along the rotating preform. Uncler the influ-enee of the surfaee tension of the preEorm material, the dicl~eter of the duet gradually deereases mill -the duct closes entirely on passing the heating zone for the last time. This ~ethocl is used in particular in closing hollow preforms obtainecl by jeans of an RID or PCVD process. In the case of porous preforms which are con-strueted from vltreous particles, the duct eloses durinq the consoli-~7q3 ~7~7Pl~ 10.603 2 10.01.1984 dation or vitrifieation of the par-ticles.
A generally used dopant in -the manufac-ture of optical fibres from c~lartz glass is germanium dioxide (Ge~2). During eo]lap-sing of preforms comprising a central duct in which at least the part of the preform which directly adjoins the duet eonsists o-E quar-tz glass clc)ped wi-th a eomparatively volatile clopant, for example, germa-nium dioxide, a part of the dopant may evaporate. This results in a disturbanee of the refraetive index profile. In this case the dif-fusion of the dopan-t from parts of the preform situated fur-ther aT.A7ay from the central duet also plays a part. Ihe profile disturbarlee has an adverse influenee on the bandwidth of the optieal fibre.
It has already teen suggested to reduce the profile disturbanee by leading a fluorine-eontaining gaseous e-tehant -through the central duct during the collapsing of the hollow preform. The gaseous etchant reacts with a layer adjoining the duet and ,7hich has been depleted of dopant by evaporation, while forming gaseous etching products (see, for example, GB 2,084,988 A and FR 2,504,514). As a gaseous etchant are mentioned mix-tures of oxygerl and diehlorodifluoro-nethane (CCl2F2), sulph~lr hexaf]uoride (SF6), earbon te-trafluoricle (CF4), -trichloromonofluoromethane (CCl3F) and nonoehlorotrifluoro-nethane (CClF3).
I-t has been found in practice tha-t -the said compounAs do not glve satisfae-tory resul-ts. It has beerl fo~mcl that the disturbanee of -the refrac-tive index profile can be reclueed, but it canno-t be avoidecl.
For tha-t purpose, for example, reference may be made to -the Fic~lre in the above-cited French Patent Applica-tion 2,504,514 and -the pertaining part of the speeifieation.
It is an objeet of the invention to entirely avoid any disturbanee of the refractive index profile. It has teen fo~md -that this objeet ean be aehieved by means of a method which is characterizecl in that the f]uorine-eontaining etehant which durinq closing is passed through the central duct consists of a mix-hlre of oxygen and one or more gaseous fluorocarbon compo~md(s), selectee from the group eon-sisting of hexafluoroethane (C2F6), octaf~uoropropane (C3F8) ancl cleea-fluoro-n-butane (n-C~F10). By using the said eompolmc1(s) it is achievecl that the available fluorine concentration per s-tanAarA unit of volume is essentially larger, in a manner ~7hich is Aecisive of the ou-tcome of the etching process, -than with the so fclr sugcrestel compounds a Pi 10.G~3 3 10.01.198 including the already previously suggested SF6. Although SF6 per s-tanclard unit of voile ccmprises an octal amoun-t of f]uorine as, for example, C2F6, it has been -found in prac-tice -that at -the collapsing -temperatures used the quan-tity of SiO2 etched-away does not corres-pond to the theoretically calculated c~lantity on the basis of thec~lantity of available SF6. The incomplete reaction in~les the control of the etching process and the reproducibility is bad. This is not the case with, for example, C2F6, since its fluorine conten-t is obviously used completely. The compounds C3F8 and C4F10 have a still higher 0 fluorine c~lantity in standard conditions.
When the said fluorine compounds are used, the fluorine js presented in a more concentrated form so that a smaller supply (volume of gas which is supplied per unit time) will suffice than is the case with compounds which comprise 1ess fluorine err molecule. The etching process may now ke carried out in the last stage of the collapsing process. The inner surface of the duct then is so much smaller that the evaporation of dopant only plays a minor role.
The quantity of evaporating dopant is proportional to the surface area.
It has consequently been found that it is possible when hexafluoroethane is used to completely remove the so-calleil dip in the refractive index profile of gradient index fibres. The qaseous etchant preferably comprises 5-30 vol.O C2F6, the remaincler beinq oxygen. The pressure cluring passing-through -the etchant may at most OR fat to -the pressure of the ambient atn~sphere. rrhe gas supply during the collapsincJ process may be 50 to 60 sccm.PreEerab]y, oxygen is passed -throuyh the cen-tral duct in -the firs-t staqe of the collap--sing process until the diameter of the cluct has clecreasecl until it is a-t rr,os-t 1 rnm the fluorine-con-taining etchant is then passec1-throuqh the duct and -the duct is closed. I~hen etchants cure used in which the fluorine is presented in a concentrated forrn, sr~ll quantities of etchant will suffice. The actual etching -takes place in the very last stage of closing the cluct. Since the inner surface is then small, the quantity of dopant evaporated from the doped layer eYposed during etching is proportionally small.
The invention will now be describecl in greater detail with reference to a n~unber of examples and the accompanyinq draying in which Fiy. 1 shows the refractive incle~Y profile of an optical Pit 10.G03 4 10.01.1984 fibre drawn from a non-etched preform;
Fig. 2 shows the refractive index proEile of an optical fibre drawn from a preform etched with CF4 according to E'rench ` Paten-t Application 2,504,514;
Fig. 3 shows the refrac-tive index profile of an op-tical fibre drawn from a preform etched with C2F6 according to the invention;
Fig. 4 shows the clepenclence of the attenua-tion on the wavelength for optical fibres which are clrawn from a non-etched preform (curve A) and from a preform etched with C2F6 (curve B); and Fig. 5 shows the refractive index profile of an etched preform determined with a so-called preform analyser.
The experiments to be described hereinafter were carried out with a ~uar-tz glass -tube(~eralux') having an outside diameter of 21 mm and an inside diameter of 17 mm and which was coatecl inter-nally with a layer having a thickness of 450 /um built up from 900 sub-layerseach having a thickness of 0,5 /um. The ]ayer showed a varying refractive index. The layer consisted of c~uartz glass dopecl with an increasing quantity of germanium dioxide. The layer was provided by Hans of a non-isothermal plasma cleposition process such as -that described in US-RE 30635- Collapsing too place k~ reciprocating a burner past the rotating tuke.
E'ig. 1 sho~7s the reEractive index profile oE an optical fibre obtained by drawing a preEorm into a fibre havincJ a clkY~e-ter of 125 /um. The width oE the clip a-t the level x is 4.~6 of dis-tance En. The depth of t'he dip is 78.5~ of the clistance Erom the peak oE
the curve to the point y.
Fig. 2 shows the influence of etching of a preform with CF4, as described in French Paten-t Application 2,504,514, on the refractive index profi]e. The depth of the dip after etching is still half the depth of the dip if no etching is carried out(curve wi-thout etching, curve B with etching).
Fig. 3 sho~7s the refractive index profile of an optical fibre obtained by drawing from a preform e-tchecl according to the invention. For that purpose, oxyqen was first led -through the central duct during the moving of the burner past the tube, The supply of oxygen gas was reduced propor-tionally with the decrease of the dic~eter of the cen-tral duct. it -the instcmt the inside cliameter is approxin~lte-ly 1 mm, C2F6 is added -to -the oxygen. The gas mixture now has the com-if 10.G03 5 10.01.198~
position ~8 scem 2 -I 10 scem C2F6. It appears from Fig. 3 that -there is no dip in the refractive index profile of the finished fire.
Fiq. 4 shows two curves which indicate the dependence of the attemlation of the transported light signal on the wavelencJ-th.
Curve A re~a-tes to a fibre obtained from a non-etched preform. Curve relates -to a fibre obtainecl according -to the invention. It has heen found that the so-callecl water peak at 1380 mm is significant]y redueecl by e-tehing wi-th C2F6.
Fig. 5 shows the refrac-tive index profi]e in apreform.
o From this it appears tha-t due to the e-tching with C2F6 the so-called dip in a preform is absent.
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Method of manufacturing a solid preform for drawing op-tical fibres, in which method a preform comprising a central duct extending in the longitudinal direction and wherein at least the part of the preform bounding the duct consists of quartz glass doped with a dopant which is more volatile than silica, is heated while passing a fluorine-containing gaseous etchant through the duct, to a temperature at which the duct starts closing spontaneously so as to form a solid preform of the same length, characterized in that the fluorine-containing gaseous etchant consists of a mixture of oxygen and one or more gaseous fluorocarbon compound(s), selected from the group consisting of C2F6, C3F8 and n-C4F10.
2. A method as claimed in Claim 1, characterized in that during the step of closing the duct oxygen is passed through the cen-tral duct until the diameter of the duct has been reduced to not more than 1 mm, after which a mixture of oxygen and one or more fluoro-carbon compound(s) selected from the group consisting of C2F6, C3F8 and n-C4F10 is passed through the duct.
3. A method as claimed in Claim 1, characterized in that the fluorine-containing gaseous etchant consists of a mixture of 90-70%
by volume of oxygen and a total quantity of 10-30% by volume of one or more fluorocarbon compound(s), selected from the group consisting of C2F6, C3F8 and n-C4F10.
by volume of oxygen and a total quantity of 10-30% by volume of one or more fluorocarbon compound(s), selected from the group consisting of C2F6, C3F8 and n-C4F10.
4. A method as claimed in Claim 1, characterized in that the pressure in the central duct during closing is equal to the pres-sure of the ambient atmosphere.
5. A method as claimed in Claim 1, characterized in that the gas supply during closing the duct is 50-60 sccm.
6. A method of manufacturing an optical fibre, characterized in that a solid preform obtained by means of a method as claimed in Claim 1 is heated to the drawing temperature, and is drawn to form an optical fibre.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8300650 | 1983-02-22 | ||
| NL8300650A NL8300650A (en) | 1983-02-22 | 1983-02-22 | METHOD FOR MANUFACTURING A SOLID FORM FOR DRAWING OPTICAL FIBERS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1236966A true CA1236966A (en) | 1988-05-24 |
Family
ID=19841452
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000447737A Expired CA1236966A (en) | 1983-02-22 | 1984-02-17 | Method of manufacturing a solid preform for drawing optical fibres |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4793843A (en) |
| EP (1) | EP0117009B1 (en) |
| JP (1) | JPS59156932A (en) |
| AT (1) | ATE21886T1 (en) |
| AU (1) | AU565484B2 (en) |
| CA (1) | CA1236966A (en) |
| DE (1) | DE3460590D1 (en) |
| NL (1) | NL8300650A (en) |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU567192B2 (en) * | 1983-02-08 | 1987-11-12 | Nippon Telegraph & Telephone Corporation | Optical fibre preform manufacture |
| JPS61227938A (en) * | 1985-04-03 | 1986-10-11 | Sumitomo Electric Ind Ltd | Preparation of parent material for optical fiber |
| FR2776652B1 (en) * | 1998-03-30 | 2000-04-28 | Alsthom Cge Alcatel | IMPROVED PROCESS FOR SHRINKING A FIBER OPTIC PREFORM |
| US6718800B2 (en) * | 1999-03-08 | 2004-04-13 | Fitel Usa Corp. | Method of collapsing a tube for an optical fiber preform |
| US6532773B1 (en) * | 2000-06-30 | 2003-03-18 | Fitel Usa Corp. | Method of modifying the index profile of an optical fiber preform in the longitudinal direction |
| AUPQ935500A0 (en) * | 2000-08-11 | 2000-09-07 | Jds Uniphase Pty Ltd | Optical waveguide with minimised cladding mode coupling |
| US6542665B2 (en) * | 2001-02-17 | 2003-04-01 | Lucent Technologies Inc. | GRIN fiber lenses |
| NL1017523C2 (en) * | 2001-03-07 | 2002-09-10 | Draka Fibre Technology Bv | Method for manufacturing an optical fiber suitable for high transmission speeds. |
| KR100692652B1 (en) * | 2001-11-05 | 2007-03-13 | 엘에스전선 주식회사 | Optical fiber preform manufacturing method |
| WO2003052173A1 (en) * | 2001-12-14 | 2003-06-26 | Corning Incorporated | Two step etching process for an optical fiber preform |
| NL1019675C2 (en) * | 2001-12-28 | 2003-07-01 | Draka Fibre Technology Bv | Method for heating a hollow substrate tube into a rod-shaped preform with heating. |
| NL1020781C2 (en) | 2002-06-06 | 2003-12-09 | Draka Fibre Technology Bv | Method for manufacturing a solid preform. |
| WO2004041737A1 (en) * | 2002-11-07 | 2004-05-21 | Ls Cable Ltd. | Method for manufacturing an optical fiber preform by mcvd |
| US20040107734A1 (en) * | 2002-12-04 | 2004-06-10 | Paresh Kenkare | Systems and methods for fabricating optical fiber preforms |
| US20050284184A1 (en) * | 2004-06-29 | 2005-12-29 | Grant Baynham | Methods for optical fiber manufacture |
| KR100624247B1 (en) * | 2004-07-02 | 2006-09-19 | 엘에스전선 주식회사 | Multimode optical fiber for high data rate local area network |
| US20100154478A1 (en) * | 2008-12-01 | 2010-06-24 | Panduit Corp. | Multimode fiber having improved index profile |
| US8351027B2 (en) | 2009-06-15 | 2013-01-08 | Panduit Corp. | Method and metric for selecting and designing multimode fiber for improved performance |
| NL2006962C2 (en) * | 2011-06-17 | 2012-12-18 | Draka Comteq Bv | DEVICE AND METHOD FOR MANUFACTURING AN OPTICAL FORM. |
| NL2009962C2 (en) * | 2012-12-11 | 2014-06-12 | Draka Comteq Bv | Method for activating an inner surface of a hollow glass substrate tube for the manufacturing of an optical fiber preform. |
| JP5932674B2 (en) * | 2013-01-24 | 2016-06-08 | 三菱電線工業株式会社 | Rare earth doped optical fiber and manufacturing method thereof |
| NL2015161B1 (en) | 2015-07-13 | 2017-02-01 | Draka Comteq Bv | A method for preparing a primary preform by etching and collapsing a deposited tube. |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2444100C3 (en) | 1974-09-14 | 1979-04-12 | Philips Patentverwaltung Gmbh, 2000 Hamburg | Process for the production of internally coated glass tubes for drawing optical fibers |
| JPS5430852A (en) * | 1977-08-11 | 1979-03-07 | Nippon Telegr & Teleph Corp <Ntt> | Production of glass fiber for optical communication |
| JPS5510468A (en) * | 1978-07-10 | 1980-01-24 | Nippon Telegr & Teleph Corp <Ntt> | Production of glass fiber for light communication |
| JPS55144436A (en) * | 1979-04-26 | 1980-11-11 | Dainichi Nippon Cables Ltd | Producing optical fiber matrix |
| JPS55166647A (en) * | 1979-06-15 | 1980-12-25 | Fuji Photo Film Co Ltd | Photoconductive composition and electrophotographic receptor using this |
| US4425146A (en) * | 1979-12-17 | 1984-01-10 | Nippon Telegraph & Telephone Public Corporation | Method of making glass waveguide for optical circuit |
| DE3000954C2 (en) * | 1980-01-12 | 1982-04-22 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Process for etching glass surfaces, especially in the manufacture of glass fiber light guides |
| DE3031160A1 (en) * | 1980-08-18 | 1982-04-01 | Siemens AG, 1000 Berlin und 8000 München | Cleaning of glass surfaces by etching with gas - esp. where mixt. of oxygen and sulphur hexa:fluoride is used to clean bore of quartz tube used to make blank for mfg. optical fibres |
| GB2084988B (en) | 1980-10-02 | 1984-06-06 | Post Office | Methods of etching materials containing silicon |
| JPS591222B2 (en) * | 1980-10-08 | 1984-01-11 | 日本電信電話株式会社 | Optical fiber manufacturing method |
| FR2504514B1 (en) | 1981-04-24 | 1985-05-31 | Comp Generale Electricite | PROCESS FOR PREPARING AN OPTICAL FIBER BLANK |
| DE3205345A1 (en) * | 1982-02-15 | 1983-09-01 | Philips Patentverwaltung Gmbh, 2000 Hamburg | "METHOD FOR THE PRODUCTION OF FLUOREDOTED LIGHT-CONDUCTING FIBERS" |
| NL8201453A (en) * | 1982-04-06 | 1983-11-01 | Philips Nv | METHOD FOR MANUFACTURING OPTICAL FIBERS |
| JPH0635323B2 (en) * | 1982-06-25 | 1994-05-11 | 株式会社日立製作所 | Surface treatment method |
| US4453961A (en) * | 1982-07-26 | 1984-06-12 | Corning Glass Works | Method of making glass optical fiber |
-
1983
- 1983-02-22 NL NL8300650A patent/NL8300650A/en not_active Application Discontinuation
-
1984
- 1984-02-17 CA CA000447737A patent/CA1236966A/en not_active Expired
- 1984-02-20 AU AU24737/84A patent/AU565484B2/en not_active Ceased
- 1984-02-20 AT AT84200225T patent/ATE21886T1/en active
- 1984-02-20 DE DE8484200225T patent/DE3460590D1/en not_active Expired
- 1984-02-20 EP EP84200225A patent/EP0117009B1/en not_active Expired
- 1984-02-21 JP JP59029664A patent/JPS59156932A/en active Granted
-
1987
- 1987-03-20 US US07/029,351 patent/US4793843A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE3460590D1 (en) | 1986-10-09 |
| JPS59156932A (en) | 1984-09-06 |
| ATE21886T1 (en) | 1986-09-15 |
| US4793843A (en) | 1988-12-27 |
| AU2473784A (en) | 1984-08-30 |
| NL8300650A (en) | 1984-09-17 |
| AU565484B2 (en) | 1987-09-17 |
| EP0117009B1 (en) | 1986-09-03 |
| JPH0476935B2 (en) | 1992-12-07 |
| EP0117009A1 (en) | 1984-08-29 |
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