CN101305305A

CN101305305A - Microstructured optical fiber and its manufacturing method

Info

Publication number: CN101305305A
Application number: CNA2006800415145A
Authority: CN
Inventors: D·C·布克宾德; R·M·菲亚克; M·-J·李; M·T·穆塔格; P·坦登
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2005-11-08
Filing date: 2006-10-19
Publication date: 2008-11-12

Abstract

Microstructured optical fiber and method of making the same. Glass soot is deposited and then consolidated under conditions which are effective to trap a portion of the consolidation gases in the glass to thereby produce a non-periodic array of voids which may then be used to form a void containing cladding region in an optical fiber. Preferred void producing consolidation gases include nitrogen, argon, CO2, oxygen, chlorine, CF4, CO, SO2 and mixtures thereof.

Description

Microstructured optical fiber and manufacture method thereof

Cross-reference to related applications

The application requires the U.S. Provisional Application series the 60/734th of submission on November 8th, 2005 according to 35U.S.C. § 119 (e), No. 995, the provisional application series of submitting on April 5th, 2006 the 60/789th, No. 798, and the provisional application series the 60/845th of submission on September 20th, 2006, No. 927 right of priority, the full content of these applications all is incorporated by reference into herein.

Background of invention

1. invention field

The present invention relates generally to optical fiber, more particularly relate to microstructured optical fiber and the method for preparing microstructured optical fiber.

2. technical background

In commercial Application, used for two more than ten years by the optical fiber that glass material forms.Although these optical fiber have been represented a huge leap forward of communication field, people still constantly study the optical fiber designs that can supply to substitute.A kind of substituted for optical fibers likely is the optical fiber of micro-structural, and it comprises along vertical continuous hole (hole) or hole (void) of the axle of optical fiber.Described hole comprises air or inert gas usually, but also can comprise other material.The optical fiber of most of micro-structurals has a large amount of hole that is positioned at around the core, and continuous distribution is gone up along the long distance (for example tens of rice or longer) of described fibre length direction in described hole, and common described hole can be extended along the whole length of optical fiber.These coat the hole and most preferably arrange around the core of optical fiber with the periodic form of rule.In other words, if get the xsect of optical fiber, then can in essentially identical periodicity void structure, find identical independently hole along the length of optical fiber.The fiber of these micro-structurals comprises United States Patent (USP) the 6th, 243, those that describe in No. 522.

The optical fiber of micro-structural can be designed to have the character of wide range, can be used for many kinds and uses.For example, people have designed a kind of optical fiber of micro-structural, and this optical fiber comprises solid glass core, and are positioned at around a large amount of hole in the coating zone of described glass core.Can the position and the size in described hole be designed, obtain having from high negative value to height the microstructured optical fiber that the optional position disperses in scope.These optical fiber can be used for for example dispersion compensation.The optical fiber of solid core micro-structural also can be designed to be the single mode form in very wide wavelength coverage.Most of solid core microstructured optical fibers are by total internal reflection mechanism light conducting; The low-refraction in hole can reduce the residing effective refractive index that coats the zone in this hole.

The optical fiber of micro-structural is usually by so-called " piling up-draw " manufactured, and the method is piled up silica bar and/or pipe array with close stack manner, forms preform, uses conventional tower equipment to be drawn into fiber then.There are some defectives in described piling up-drawing.Hundreds of billots (cane) (forming by rod or pipe) are as thin as a wafer assembled up very difficulty, but also may pile up and the cylindrical billot that stretches in have the gap cavity, these cavitys may be introduced soluble impurity and granule foreign, thereby cause the decay of optical fiber significantly, also can produce undesirable interface, and the shaping again or the distortion that bring initial hole.In addition, lower throughput rate and higher cost make this method extremely not be suitable for commercial production.

Summary of the invention

One aspect of the present invention relates to a kind of method of making optical fiber, and this method comprises the predispersed fiber formed body that comprises cigarette ash by chemical vapor deposition (CVD) operation formation.Under certain conditions, described cigarette ash preform is fixed in the gas atmosphere of this preform, described fixed condition can make in described consolidation step, the described gas atmosphere of a part is captured in the described preform effectively, thereby form the hole or the hole of non-periodic distribution in described fixed preform, each hole is corresponding at least a zone that is captured in the fixed gas in the described fixed glass preform.Use the described fixed preform that wherein comprises the hole to prepare optical fiber then.In consolidation step, at least a portion in the hole that forms in described predispersed fiber formed body is retained within the optical fiber of drawing.Become clad by the zone design that will comprise the hole corresponding to optical fiber, make the optical fiber of these gained comprise core district and clad district, described core district has first refractive index, described clad district has second refractive index of the refractive index that is lower than core, and described lower refractive index to small part is because cause in the hole that exists in the clad.Can use the alternative method of methods described herein or other method that the zone that contains the hole is provided in clad, thereby improve the bending property of optical fiber.For example, by using optical fiber designs as herein described and method, can make a kind of optical fiber, this optical fiber is in 10 millimeters mandrel bending, and its decay in 1550 nanometers increases, and the increase amplitude is enclosed less than 20dB/, be more preferably less than the 15dB/ circle, be more preferably less than the 10dB/ circle.Similarly, use optical fiber designs as herein described and method, can make a kind of optical fiber, it is when being 20 millimeters mandrel bending around diameter, decay in 1550 nanometers increases, and the increase amplitude is enclosed less than 3dB/, is more preferably less than the 1dB/ circle, be more preferably less than the 0.5dB/ circle, most preferably enclose less than 0.25dB/.It is the fiber of single mode and multimode that method as herein described and optical fiber designs can be used to be manufactured under 1550 nanometers.

Preferably, described hole is located substantially in the clad of described optical fiber, more preferably is positioned at the clad of described optical fiber fully, makes them surround described core in comprising the zone in hole, does not preferably have described hole in the core zone substantially.Some preferred embodiment in, described hole is positioned at that core with described optical fiber separates contains the zone, hole.For example, the ring that contains the zone, hole of thin (for example radial width is more preferably less than 30 microns less than 40 microns) can separate with the core of described optical fiber, but does not extend to the periphery of described optical fiber fully.The zone and the core that will contain the hole separate and will help to reduce the decay of described optical fiber in 1550 nanometers.Use thin ring will help to make that optical fiber is single mode in 1550 nanometers.Described optical fiber can comprise germanium oxide (germania) or fluorine, perhaps also can not comprise germanium oxide (germania) or fluorine, be used for regulating the refractive index of the core and/or the clad of optical fiber equally, but these adulterants also can be avoided using, and use the hole to regulate the refractive index of clad separately with respect to core, make light be directed core transmission along optical fiber.Concretion technology by using this paper to disclose can form the hole is non-periodic distribution in xsect optical fiber.Non-periodic distribution represents when observing the xsect of optical fiber, the hole randomly or aperiodicity be distributed on the part of optical fiber.The xsect of getting along the diverse location of fiber length can present different xsect pattern of holes, and promptly each xsect will have pattern of holes, distribution and the size of different slightly random orientations.(elongation) extended along the length (promptly being parallel to the longitudinal axis) of optical fiber in these holes, but is not to extend along the whole length of whole optical fiber.Although without wanting to be limited by theory, it is believed that described hole extends less than several meters along fiber lengths, extend in many cases less than 1 meter.

By using the concretion technology in generation as herein described hole, can make the optical fiber with following character: this optical fiber has the clad zone, total optical fiber hole area percent in this clad zone (being total cross-sectional area * 100 of total cross-sectional area in hole divided by optical fiber) is greater than 0.01%, more preferably greater than 0.025%, more preferably greater than 0.05%, more preferably from about greater than 0.1%, more preferably from about greater than 0.5%.Prepared optical fiber, its total hole area percent is approximately greater than 1%, in fact more greater than about 5%, even 10%.But, it is believed that according to optical fiber designs, when total hole area percent less than 1%, even less than 0.7% the time, the bending property that will obtain to significantly improve.Some preferred embodiment in, the total hole area percent in the described optical fiber is more preferably less than 10%, most preferably less than 5% less than 20%.These clad zones that contain the hole can be used to reduce the refractive index with respect to core, thereby form the clad zone of direct light along the core transmission of optical fiber.By selecting suitable cigarette ash consolidation condition (will be described below), can finish the useful optical fiber designs of many kinds.For example, by selecting the maximum hole size in the clad, make it less than the light wavelength that will transmit (being less than 1550 nanometers for example) for some telecommunication systems, preferably less than will be, the fiber that obtains low decay under the condition of expensive adulterant can need not to use along half of the light wavelength of Optical Fiber Transmission.Therefore, for various application, need to form described hole, make in the described optical fiber at least greater than 95%, preferably all hole all has the maximum void size in the clad of optical fiber, promptly, be more preferably less than 775 nanometers, most preferably from about less than 390 nanometers less than 1550 nanometers.Similarly, the mean diameter in hole is more preferably less than 2000 nanometers less than 7000 nanometers in the preferred fiber, is more preferably less than 1550 nanometers, and most preferably less than 775 nanometers, all these mean diameters all can use method as herein described to obtain.Use the optical fiber of method manufacturing as herein described can obtain these mean diameters, its standard deviation is in 1000 nanometers, more preferably in 750 nanometers, most preferably in 500 nanometers.In some embodiments, optical fiber as herein described comprises less than 5000 holes in specific optical fiber vertical cross-section, comprises in some embodiments less than 1000 holes, and in some embodiments, total hole number is less than 500.Certainly, most preferred optical fiber will show these combination of features.Therefore, for example, a particularly preferred embodiment of optical fiber will have in an optical fiber less than 200 holes, the maximum gauge in described hole is less than 1550 nanometers, mean diameter is less than 775 nanometers, larger diameter can obtain useful resistant to bending optical fiber with hole greater number but be to use.The mean diameter in number of cavities, hole, maximum gauge and total hole area percent all can be by amplifying about 800 times scanning electron microscope and image analysis software (ImagePro for example, it is available from Maryland, USA Yin Chun city (Silver Spring, Maryland, the help of this company limited of Midi Sai Bonai Ti Ke (Media Cybernetics, Inc.)) USA) is calculated.

Another aspect of the present invention relates to the optical fiber of the micro-structural that can use method preparation mentioned above.A kind of optical fiber of such micro-structural comprises core zone and clad zone, described core zone has first refractive index, described clad zone has second refractive index that is lower than described core areas diffract rate, and this is at least in part because wherein exist the hole of non-periodic distribution.Therefore, transmission is retained in described in-core substantially by the light of described optical fiber.The maximum gauge in described hole preferably is equal to or less than 1550 nanometers, the optical fiber of gained under at least a wavelength of 600-1550 nanometer the decay of (most preferably wavelength is 1550 nanometers) less than the 500dB/ km, more preferably in 1550 nanometers less than the 200dB/ km.In this article, " decay " if then described optical fiber is multimode in 1550 nanometers, represents then that the multimode of described optical fiber decays as not specifically writing " multimode decay " or " single mode decay ", if described optical fiber is single modes in 1550 nanometers, then represent the single mode decay.By using the concretion technology in generation as herein described hole, can make a kind of optical fiber, this optical fiber has the zone of sealing, this regional hole area percent of sealing the zone is greater than 0.5%, more preferably from about greater than 1%, more preferably from about greater than 5%, most preferably from about greater than 10%.Specifically, can within 10 microns distance, prepare this coating zone that comprises the hole at core with described optical fiber.Although by using the techniques described herein can avoid using the adulterant that is used for regulating refractive index, preferably with at least a germanium oxide or fluorine or similarly refractive index adjusting adulterant be used in combination with the hole of the non-periodic distribution in the coating zone that is positioned at described optical fiber.But whether using germanium oxide and/or fluorine is not key factor, and for example, if necessary, described optical fiber can complete or basic oxygen-free germanium and fluorine.In this article, " non-periodic distribution " expression hole or hole are acyclic, and promptly they periodically are not arranged within the fibre structure.Although method of the present invention can not make each independently with respect to other independently hole (fiber of the micro-structural of many other kinds is so periodically to be provided with) is set periodically in the hole, method as herein described can be provided with relatively large or the hole of a small amount of at the radially-arranged all places of optical fiber.For example, by using method as herein described, can so that with the fiber cores adjacent areas in the regional hole area percent in hole be higher than the percentage in other zone in the optical fiber (for example within the fiber cores or the outside zone that coats).Similarly, can be along described interior mean void size and the hole Size Distribution in zone that contains the hole of radial and axial (along its length promptly) control of optical fiber.Therefore, the even aperiodicity array in hole can a zone in optical fiber be set,, mean void size in relative hole area percent and this zone be kept constant along the length of described fiber.Although described optical fiber is not limited to the diameter of any specific, the external diameter of preferred described optical fiber is more preferably less than 375 microns less than 775 microns, most preferably less than 200 microns.

This fiber can be used for telecommunications network (normally 850,1310 and 1550 nanometer windows), comprise telecommunication, subway, access, building and data center, and the data telecommunications of buildings and mobile thing (car, motorbus, lorry, aircraft) purposes is used and control area network (being generally the 600-1000 nanometer range).This telecommunications network generally includes transmitter and the receiver that is connected with fiber optics.Therefore,, need to form the hole, make maximum void size in the optical fibre packages coating, be more preferably less than 775 nanometers, most preferably from about less than 390 nanometers less than 1550 nanometers for many application.

This optical fiber also can be used as the ultraviolet of medical science, illumination, photoetching and commercial Application to the infrared light conduit.A kind of clad of preferred optical fiber comprise be positioned within the clad, preferably with core diameter at a distance of 10 microns with the zone, hole of a large amount of non-periodic distribution, the maximum gauge that records described hole along radially (perpendicular to the cross-directional of the optical fiber longitudinal axis) of optical fiber is equal to or less than 1550 nanometers, more preferably is equal to or less than 775 nanometers.The clad of another kind of preferred optical fiber, the zone, hole that in clad, comprises a large amount of non-periodic distribution, they and core are spaced apart, with core diameter to distance at a distance of in 20 microns, described hole is equal to or less than 1550 nanometers along the maximum gauge of optical fiber radial measurement, more preferably be equal to or less than 775 nanometers, most preferably from about less than 390 nanometers.The clad of another kind of preferred optical fiber, the zone, hole that in clad, comprises a large amount of non-periodic distribution, the outer peripheral radial distance of they and core is in 40 microns, radial distance along described optical fiber records, the maximum gauge in described hole is equal to or less than 1550 nanometers, more preferably be equal to or less than 775 nanometers, most preferably from about less than 390 nanometers.Compare with the various optical fiber that prior art is known, optical fiber disclosed herein shows dramatic benefit.For example, compare with the optical fiber of prior art, optical fiber disclosed herein can have good bending resistance, shows splendid mode field diameter simultaneously.Say that it is good, be meant by using method disclosed herein, can make a kind of optical fiber, this optical fiber is single mode in 1550 nanometers, in the bending of carrying out diameter 20 nanometers, can show every circle increases less than the decay of 0.5dB, simultaneously 1550 nanometers show greater than 10 microns, more preferably greater than 11 microns mode field diameters.This splendid bending property makes these optical fiber become the attracting candidate material of following application: Fiber to the home, incoming fiber optic (access fiber), indoor fiber optic applications and optical fiber bonding line (fiber segment (1-20 rice) that these are normally short has connector to link to each other with optical system or device at each end).For example, optical fiber disclosed herein can be used for comprising transmitter, receiver, the optical fibre telecommunications system of the optical fiber that is connected with receiver optics with described transmitter.Preferably, in these are used (promptly when described optical fiber in telecommunication system as conduction optical fiber in), described optical fiber does not contain any active element of erbium and so on.

In addition, optical fiber as herein described can support and have high-NA (for example in 1550 nanometers greater than 0.2, more preferably greater than 0.4, most preferably greater than 0.6), tolerance that this has promoted the ability that their link to each other with other optical lasers source and has improved the joints of optical fibre.This optical fiber still is used for the splendid candidate material of vehicular applications.In such application, most preferably the maximum hole size of optical fiber is more preferably less than 775 nanometers approximately less than 1550 nanometers, most preferably from about less than 390 nanometers.

The optical fiber that this paper discloses can be made by the manufacturing process of lower cost, because if need, can avoid using the adulterant of the costliness of fluorine and/or germanium oxide and so on, similarly, can avoid piling up-drawing autofrettage.It is (positive that the present invention also can carry out the control of chromatic dispersion flexibly, flat or negative), for example, for signal Processing finish big positive dispersion (in 1550 nanometers＞30ps/nm/Km), perhaps can be used for dispersion compensation negative dispersion optical fiber (for example 1550 nanometers＜-200ps/nm/Km).The clad that method perhaps as herein described may simply be optical fiber adds the hole to improve its bending resistance, and one or more following materials have mixed in the described clad: germanium oxide, phosphorus, aluminium, ytterbium, erbium, fluorine or other conventional fiber dopant material.In another embodiment, method as herein described can be used to prepare the optical fiber (being the optical fiber that in-core does not contain Germanium dopants) of silica core, and its cutoff wavelength is lower than 800 nanometers, under 1550 nanometers, its numerical aperture is approximately greater than 0.08, more preferably from about greater than 0.10.

In the detailed description hereinafter other features and advantages of the present invention will be described more specifically, those of ordinary skills are by the description of this paper or by implementing the present invention, can be easy to recognize these feature and advantage, the content of this paper comprises following detailed description, claims and accompanying drawing.

The detailed description that should be appreciated that above general introduction and following embodiment of the present invention is to be used to provide overview or framework, so that understand desired character of the present invention and feature.Further understand the present invention with accompanying drawing, accompanying drawing is combined in the instructions, constitutes the part of instructions.Accompanying drawing has shown each embodiment of the present invention, is used for explaining principle of the present invention and operation with instructions.

The accompanying drawing summary

Fig. 1 has shown the OVD method that is used for forming the cigarette ash preform.

Fig. 2 has shown the side cross-sectional, view according to concretion method of the present invention.

Fig. 3 has shown the drawing again that is used for forming the core billot.

Fig. 4 has shown the fixed of the cigarette ash that is deposited on the core billot.

Fig. 5 has shown the complete fixed preform that obtains by consolidation step shown in Figure 4.

Fig. 6 has shown the microphoto of the optical fiber of making according to an embodiment of the invention.

Fig. 7 and Fig. 8 have shown the rod in the tubing autofrettage that can be used for the whole bag of tricks of the present invention together.

Fig. 9 has shown drawing and the equipment that can be used for method of the present invention.

Figure 10 has shown the SEM microphoto of the optical fiber of making according to an embodiment of the invention.

The detailed description of preferred implementation

Method of the present invention adopts the preform consolidation condition, and this condition is enough to make that the gas of significant quantity is captured in the fixed glass blank, thereby forms the hole in described fixed glass optical fiber preform.We do not remove these holes by some steps, and are to use the preform of gained to form the optical fiber that wherein has the hole.

In by conventional smoke deposition method (for example outside vapour deposition (OVD) method or vapor axial deposition (VAD) method), silicon dioxide and doped silica particle form by burning in flame, with the form deposition of cigarette ash.For OVD, by make the flame that has cigarette ash cross the cylindrical target rod the axle, layer by layer with the outside of particle deposition at described cylindrical target rod.Then, the cigarette ash preform of this porous is handled with drying agent (for example chlorine), anhydrates and metallic impurity to remove, and in consolidation furnace, carries out fixed under 1100-1500 ℃ temperature or calcining then, forms the glass blank that does not contain the hole.It is the dominant mechanism of sintering that surface energy drives the drag flow sintering, causes the sealing in densification and cigarette ash hole, thereby forms the glass preform of densification.In the final stage of sintering, along with the open bore sealing, being used for fixed gas can be hunted down.If dissolubility and the perviousness of captive gas under calcining heat is very high in the glass, then described gas can move in consolidation process, pass glass and arrive beyond the glass.Perhaps, still captive gas can be discharged in the following manner after the consolidation stage of optical fiber manufacture process: keep described predispersed fiber formed body a period of time, discharge by described glass preform until gas transfer, be the hole of vacuum in one or more thereby in described preform, stay.In the drawing operating process by described preform drawing optical fiber, these holes can be closed, stays no hole or do not have the optical fiber in hole substantially.Be used for making in the consolidation process of conventional Transmission Fibers, target is to make in the core zone of the optical fiber that makes and the clad zone all not contain the hole fully.Helium is a kind ofly the conventional fiber preform to be carried out be commonly used to form in the fixed process gas of atmosphere.Because helium has high permeability in glass, it is easy to discharge from cigarette ash preform and glass in consolidation process, make in helium fixed after, described glass does not contain hole or hole substantially.

The present invention uses a kind of preform consolidation condition, and this condition can cause the gas of significant quantity to be trapped in the fixed glass blank, thereby forms the hole that aperiodicity is disperseed in fixed glass optical fiber preform.People take some steps to remove these holes, but intentionally use the preform that makes to form the optical fiber that wherein has the hole.Specifically, by using lower gas of permeability and/or higher sintering rate, can in consolidation process, the hole be captured in the fixed glass.In this article, term sintered glass or fixed glass are illustrated in chemical vapor deposition smoke deposition method (for example OVD or VAD depositing operation) and afterwards, live through the glass of cigarette ash consolidation step.In described cigarette ash consolidation step, described cigarette ash experiences densification process by being subjected to Gao Re, thereby remove open space (promptly not by the hole or the hole between the cigarette ash of glassifying of densification), stay the glass (although still obviously remaining some blind bores (promptly by the hole that glassifies or the hole of densification fully) in the present invention) of complete densification.This cigarette ash consolidation step is preferably carried out in the cigarette ash consolidation furnace.Described sintering rate can be by improving sintering temperature and/or improving the downward feed rate of cigarette ash preform by the sintering zone of consolidation furnace and improve.Under some sintering condition, can make a kind of glass, the shared area fraction of the gas of wherein catching accounts for the remarkable part of the preform total area or volume.

Of the present invention one preferred embodiment in, by hole of using the non-periodic distribution in the optical fiber that method as herein described forms or the clad that the hole is arranged in optical fiber.This hole is used for reducing refractive index.By the design consolidation parameters, the maximum gauge that makes hole or hole is less than will be along the light wavelength of described fiber lengths transmission (promptly for being used for the optical fiber that telecommunication is used, for less than 1550 nanometers), this optical fiber can be used for transmitting the information of specific wavelength effectively.

Fig. 1 has shown the manufacture method of cigarette ash predispersed fiber formed body 20 that can be used according to the invention.In embodiment shown in Figure 1, on the mandrel or bait rod (bait rod) 24 that silica containing cigarette ash 22 are deposited on rotation and translation, formed cigarette ash preform 2.This technology is called as OVD or outside vapour deposition process.Preferably taper of mandrel 24.Described cigarette ash 22 forms in the following manner: the flame 30 of the glass precursor 28 of gaseous form being sent into burner 26 makes its oxidation.Provide methane (CH to burner 26 ₄) and so on fuel 32 and the burning of oxygen and so on support gas 34, and ignite to form flame 30.Mass flow controller is designated as V, provide suitable dopant compound 36 silica glass precursor 28, fuel 32 and the burning of appropriate amount to support gas 34 to burner 26 metering, and all these components are gaseous form preferably all.28,36 oxidations in flame 30 of glass former compound form cylindrical cigarette ash district 23 substantially.Specifically, if desired, can comprise dopant compound 36.For example, can comprise germanium compound, perhaps can comprise fluorine-containing compound to reduce refractive index (for example the clad of optical fiber and/or contain the refractive index in the zone in hole) as the adulterant that improves refractive index (for example improving the refractive index in the fiber cores).

As shown in Figure 2, the cigarette ash preform 20 that comprises described cylindrical cigarette ash zone 23 can be fixed in consolidation furnace 29, to form fixed blank 31 (shown in following Fig. 3).Before fixed, remove mandrel shown in Figure 1 24 to form hollow cylindrical cigarette ash blank preform.In consolidation process, cigarette ash preform 20 for example is suspended in the pure quartz muffle tubes 27 of consolidation furnace 29 by solid mechanical structure 21.Preferably, before consolidation step, described preform 20 is exposed to dry atmosphere.For example, suitable dry atmosphere can comprise the helium of about 95-99% and the chlorine of 1-5%, and baking temperature is about 950-1250 ℃, and be about 0.5-4.0 hour suitable drying time.If necessary, can use the dopant gas that for example comprises fluorine or other optical fiber adulterant that described cigarette ash preform is mixed.For example, in order to mix, can use SiF with fluorine ₄And/or CF ₄Gas.This dopant gas can use conventional doping temperature, for example at about 950-1250 ℃ of following doping 0.25-4 hour.

In consolidation step (preferably after the cigarette ash drying steps, carrying out), the temperature of rising consolidation furnace, preform 20 is fixed under suitable temperature, and is for example fixed under about 1390-1535 ℃, to form fixed preform.Perhaps can adopt gradient sintering, cigarette ash preform 20 be driven downwards by temperature in the consolidation furnace 29 remain on about 1225-1550 ℃, 1390-1535 ℃ hot-zone more preferably from about.For example, described preform can remain on isothermal region (keeping required baking temperature (950-1250 ℃) in this zone), drive described cigarette ash preform by remaining on (for example 1225-1550 ℃ of required consolidation temperature with certain speed then, more preferably 1390-1535 ℃) the zone, described speed is enough to make the temperature of preform 20 to raise with the speed greater than 1 ℃/minute.The upper area of described consolidation furnace can remain on lower temperature, and this helps drying and foreign matter removal step.Lower area can remain on fixed required higher temperature.One preferred embodiment in, the described preform that comprises cigarette ash passes through fixed hot-zone with the downward charging of the first downward feed rate, by second hot-zone, the described second downward feed rate is less than the first downward feed rate with the downward charging of the second downward feed rate for this preform then.The outside that this concretion technology causes the cigarette ash preform is than this preform remainder sintering earlier, thereby helps to catch gas, and this helps to form the hole again and keeps these holes in the fixed glass of gained.For example, described preform can contact these suitable consolidation temperature (for example being approximately higher than 1390 ℃) with first speed, described first speed be enough to make preform temperature with greater than 15 ℃/minute, raise more preferably greater than 17 ℃/minute speed, adopt the combination of at least the second downward feed rate/consolidation temperature then, this combination be enough to make described preform with at least about 12 ℃/minute, heat more preferably greater than 14 ℃/minute speed.Preferably, described first rate of consolidation causes the heating rate of described preform outside higher more than 2 ℃/minute than the heating rate of described second rate of consolidation, more preferably high more than 10 ℃/minute, more preferably from about high more than 20 ℃/minute, most preferably high more than 50 ℃/minute.If necessary, can adopt the 3rd consolidation step even five or more a plurality of other consolidation step, these steps heat with slower speed (for example less than 10 ℃/minute).Perhaps, described cigarette ash preform can be in the following manner with the faster rate sintering, to produce more hole: drive the cigarette ash preform by temperature be higher than 1550 ℃, more preferably be higher than 1700 ℃, more preferably be higher than 1900 ℃ sintering furnace hot-zone.Perhaps, can use the naked light that contacts with cigarette ash or plasmatorch beyond consolidation furnace, make described cigarette ash preform sintering with faster rate.

The preferred sintering gas (promptly in sintering step around the gas of described preform) that can be used for described consolidation step comprises and is selected from following at least a gas: nitrogen, argon gas, CO ₂, oxygen, chlorine, CF ₄, CO, SO ₂, krypton and their potpourri.This all gases is suitable for forming under the condition of consolidation temperature in hole has lower permeability in silica glass being equal to or less than described the method according to this invention.The preferred gas that these produce holes separately or be used in combination, its consumption is 5-100 volume %, is more preferably 20-100 volume %, is most preferably 40-100 volume %.Remaining sintering gas atmosphere is made up of suitable diluent or carrier gas, for example helium, hydrogen, deuterium or its potpourri.In embodiments more as herein described, for example when planning after the consolidation process in described generation hole, will be by in the other cigarette ash of OVD method deposition on the glass preform of gained or billot, preferred use the oxygen that comprises less than 10%, more preferably comprise oxygen less than 5%, the sintering gas of basic oxygen-free gas most preferably, otherwise just can cause the loss of some seeds (seed) owing to contacting with the hydrogen that forms in the OVD process.In general, gas (nitrogen, Ar, the CO in the generation hole of in sintering gas, using ₂, O ₂, Cl ₂, CF ₄, CO, SO ₂, krypton, or its potpourri) percent by volume big more, then can produce bigger and more hole in the fixed glass of gained.More preferably, the sintering gas that is used in the consolidation step process forming the hole comprises and is selected from following at least a gas: nitrogen, argon gas, CO ₂, oxygen and krypton, and their potpourri.These gases can use fully separately, perhaps use with the form of the potpourri of the carrier gas of these gases and helium and so on.The gas in a kind of particularly preferred generation hole is nitrogen.The applicant has been found that, when nitrogen and/or argon gas uses together or independent the use, when producing the gas in hole, preferred described nitrogen and/or the consumption of argon gas in described sintering atmosphere are greater than 10 volume %, more preferably greater than 30 volume %, more preferably from about greater than 50 volume %, most preferably from about greater than 65 volume %, remaining sintering atmosphere is the carrier gas of helium and so on.These gases are successfully to use greater than the concentration of 85 volume %.In fact, the highest 100% nitrogen, the highest 100% argon gas, and the highest 100% oxygen is successfully used.People are also by partial vacuum (, the sintering atmosphere that for example wherein preform is placed the about 40-750 of pressure to hold in the palm), at low permeability gas (nitrogen for example, argon gas, CO ₂, oxygen, chlorine, CF ₄, CO, SO ₂) in sintering cigarette ash produce the hole.By using the concretion technology in generation as herein described hole, can make a kind of optical fiber, this optical fiber has clad, described clad comprises the zone with hole, this zone, regional hole hole area % is greater than 0.5%, more preferably from about greater than 1%, more preferably from about greater than 5%, most preferably from about greater than 10%.In this article, zone hole area % represents to contain the total area in hole in the zone in hole divided by the described total area (along perpendicular to the described optical fiber of the cross-sectional view of described fiber axis) * 100 that contains the zone, hole, and the described zone that contains the hole is limited by described inner boundary and the outer boundary that contains the zone, hole.For example, if the radial position of the inward flange in innermost hole and fiber axis center line are at a distance of 4 microns in the optical fiber, and the radial position of the outer boundary in outermost hole and center line are at a distance of 60 microns in the described optical fiber, and the then described area that comprises the zone in hole is about the 11309-50=11259 square micron.If the described total cross-sectional area that contains hole contained in the zone in hole is 1100 square microns, the then described hole area % that contains the zone in hole is about 9.8%.

When using above-mentioned preferred sintering gas, need to use a kind of consolidation method, this method comprises that with certain speed and temperature conditions with the downward charging of described preform, described speed and temperature conditions are enough to make that the described consolidated gas of at least a portion is deliberately caught.This can carry out in the following manner, for example: with at least about 10 ℃/minute, more preferably greater than about 12 ℃/minute, heat more preferably greater than about 14 ℃/minute mode at least a portion to the cigarette ash preform.Be used for sintering temperature of the present invention and preferably be higher than 1100 ℃, more preferably be higher than 1300 ℃, more preferably be higher than 1400 ℃, most preferably be higher than 1450 ℃.A kind of particularly preferred sintering temperature is about 1490 ℃.

Fig. 3 has shown and has been used for drawing the method that is used for core billot of the present invention.For example in such embodiment, as mentioned in conjunction with the described cigarette ash preform that formed of Fig. 1, use conventional concretion technology (for example to use and be higher than 1300 ℃ consolidation temperature then, use 100% helium atmosphere) make that described cigarette ash preform is fixed, form the preform that does not contain the hole.For example, when using the predispersed fiber formed body to prepare the pure silicon dioxide core fibre, described core preform is made up of purer silicon dioxide, and the refractive index that does not wherein contain significant quantity is regulated adulterant.Perhaps, when using the predispersed fiber formed body to make the Ge-doped core fibre of pure zirconia, described core preform can be made up of core zone and optional a part of clad (for example unadulterated coated with silica layer) of Germania-doped.The fixed core blank 31 of gained places core billot draw machines 37, draws the clavate core billot section 33 that at least one class has the overall diameter that reduces by it.Described preform blank 31 is heated to for example about 1700-2000 ℃ temperature.Controller 38 provides suitable control signal by giving tension force mechanical hook-up 40 (being shown as two driving wheels herein), so that with the drop-down described billot 33 of proper speed, thus the tension force that control applies described billot.In this way, can obtain external diameter and be for example core billot 33 of the certain-length of about 1-16 millimeter.Then described core billot is carried out other smoke deposition as target or mandrel 24, perhaps be used as rod in rod (rodin tube) process in pipe, this will further be described hereinafter.

One preferred embodiment in, use above and form core billot test specimen in conjunction with the described method of Fig. 3, it can be used as the target or the mandrel of other smoke deposition, then its can to use formation technology in hole as herein described to carry out fixed, thereby finally become the clad of optical fiber.In such embodiment, for example, can use complete glass core billot fixed, no hole as the bait rod 24 in the smoke deposition step shown in Figure 1.Described glass core billot can be unadulterated silicon dioxide, thereby the optical fiber of gained will be that core is the silicon dioxide core fibre of pure silicon dioxide substantially.Perhaps, described core billot can be made up of one or two doped regions, and these doped regions form the light transmission core zone of optical fiber together.With after smoke deposition is on the glass core billot, described outer soot zone 120 can be fixed fully in consolidation furnace 129 as shown in Figure 4.Preferably, in this consolidation step, as shown in Figure 5, form the consolidation process in hole as mentioned above, comprise the fixed predispersed fiber formed body 150 in hole with formation.

As mentioned above, the preferred gas that is used to form the consolidation step in hole comprises and is selected from following at least a gas: nitrogen, argon gas, CO ₂, oxygen, chlorine, CF ₄, CO, SO ₂, krypton and their potpourri.The preferred gas that these produce the hole is used alone or in combination, and its consumption is 5-100 volume %, is more preferably 20-100 volume %, is most preferably 40-100 volume %.Remaining sintering atmosphere is made up of suitable diluent or carrier gas, for example helium, hydrogen, deuterium or its potpourri.In general, the gas (nitrogen, Ar, the CO that are used for the generation hole of sintering gas ₂, Kr, O ₂, Cl ₂, CF ₄, CO, SO ₂) percentage big more, then the hole in the fixed glass of gained will be big more and many more.The gas in a kind of particularly preferred generation hole is nitrogen, and its consumption is preferably greater than 10 volume %, and more preferably greater than 30 volume %, more preferably from about greater than 50 volume %, most preferably from about greater than 65 volume %, remaining sintering atmosphere is carrier gas, for example helium.People are also by partial vacuum (for example wherein placing preform the sintering atmosphere of the about 40-750 of pressure holder), at low permeability gas (nitrogen for example, argon gas, CO ₂, oxygen, chlorine, CF ₄, CO, SO ₂) in sintering cigarette ash produce the hole, do not need the diluents that uses permeability higher in the case, for example helium.By using the concretion technology in generation as herein described hole, can make a kind of optical fiber, the clad of this optical fiber comprises the zone of containing the hole, the regional hole area percent in this zone is greater than 0.5%, more preferably from about greater than 1%.Even also may use these technology to obtain approximately greater than 5% even approximately greater than 10% regional hole area %.Described regional hole area % is more preferably less than 20% preferably less than 50%.Most preferably, described zone with hole can not extend to the clad external margin, so that have open hole or hole on the outer fiber.

The used sintering temperature of the present invention is preferably 1100-1550 ℃, more preferably 1300-1500 ℃, most preferably is 1350-1500 ℃.A kind of preferred sintering temperature is about 1490 ℃.The atmosphere of using in the consolidation process, temperature and the preform rate of consolidation in consolidation furnace are selected, made that in the cigarette ash consolidation process gas intentionally is captured in the preform, forms the hole in fixed glass.The hole of these air inclusions preferably can not outgas before fiber draw process and/or in the process fully, makes after being drawn into optical fiber, and described hole remains in the described optical fiber.Can control many kinds of technological parameters, to change and to control the size in hole.For example, by prolonging fixed test specimen or the rising consolidation temperature can increase the size in hole, this is because the temperature that raises can cause the gas expansion that is captured in the hole in.Similarly, the size in described hole and area can be drawn condition effect.For example, in the draw machines long heating zone and/or faster draw rate can increase the size in described hole and the area percent in hole.By being chosen under the consolidation temperature, will obtain less hole at the higher gas of glass intrinsic permeability.Sintering rate also can cause remarkable influence to hole size and number of cavities.Sintering rate will cause forming more and bigger hole faster.But adopted slow sintering rate can cause not forming the hole, this is because gas will be discharged by glass if having time.Therefore, the preferred enough height of the downward feed rate of preform and/or used consolidation temperature, so as at least a portion of described preform be approximately higher than 10 ℃/minute, more preferably from about be higher than 12 ℃/minute, more preferably from about be higher than 14 ℃/minute speed and heat.In general, have the predispersed fiber formed body that hangs down cigarette ash density and will cause forming more hole.But in needs, the density of the cigarette ash that deposits in the special fiber preform can change, to produce more hole (higher regional hole area percent).For example, high density cigarette ash zone can be set directly on fixed glass (for example pure silicon dioxide) the core billot, settled density is lower than the second cigarette ash zone in the first cigarette ash zone thereon then.We find that this can make near core (promptly in high density cigarette ash zone) have higher hole area percent.The bulk density of described silica containing cigarette ash preferably is about 0.10-1.7g/cc, is more preferably 0.30-1.0g/cc.This effect also can be used to form the fixed preform that comprises the hole, its comprise low hole or do not contain the zone in hole with the zone that contains higher hole between replace; Initial cigarette ash density radial variations is greater than 3% at least 100 microns distance.This preform can be used to for example make the optical fiber with clad zone, and described clad zone is at the glass in no hole and contain alternate between the glassy zone in hole.Have this fiber that contains hole zone and do not contain the zone, hole that replaces and to show character as Bradley grid (Bragg grating).

Referring to Fig. 5, use above-mentioned technology, can form predispersed fiber formed body 150, it comprises the core zone 151 in no hole, the clad 152 in these 151 involved a large amount of holes, core zone surrounds.By in clad 152, form comprise capacity have a suitable dimension hole contain the zone, hole, clad 152 will after described predispersed fiber formed body is drawn into optical fiber, be used for guide lights by core zone 151 as the optics clad.The perhaps described zone that contains the hole can be used to improve the bending property of optical fiber.If necessary, before preform 150 is drawn into optical fiber, can be on clad zone 152 and carry out fixed with other smoke deposition.The clad material of described other deposition can be consolidated into as required and comprise the hole, also can be consolidated into not comprise the hole.

Fig. 6 has shown an example of the optical fiber that is drawn into by this preform.The optical fiber of described Fig. 6 comprises pure silicon dioxide core zone, and this core zone is surrounded by clad zone, and described clad zone comprises the hole, the position in these holes effectively direct light by described silica core.The dominant mode of the optical fiber of Fig. 6 decays to 0.28dB/km under 1550 nanometers, even this optical fiber is to be made by comparatively coarse test manufacturing equipment.But,, can reach under 1550 nanometers decay certainly less than 0.2dB/km by using more suitable device.

Perhaps, can be not with smoke deposition on the core billot that has formed, and adopt above-mentioned manufacturing process to form above in conjunction with the described fixed glass tubing that wherein has the zone that contains the hole of Fig. 2, this tubing can be used as the sleeve pipe of core billot.For example, said method can be used to form the cigarette ash preform on removable mandrel 24, removes described mandrel then, makes described cigarette ash preform fixed as mentioned above, forms the fixed glass tube that comprises the hole.The tubing that wherein comprises the hole 65 of gained can be used as the sleeve pipe of core billot 35.This sleeve pipe can be finished by the rod of the routine in the tubing manufacturing technology for example, as shown in Figure 7 and Figure 8.In Fig. 7, (promptly do not contain the adulterant that increases refractive index substantially with pure, germanium for example) silica core billot 35 inserts and comprises in the wrap tube portion 65 in hole, but described core zone or clad also the refractive index correctives of available routine (for example germanium or fluorine) mix.In Fig. 8, core billot 35 and wrap tube portion 65 are heated to suitable temperature (for example being approximately higher than 1300 ℃ to 1500 ℃), use then that known rod is drawn to than minor diameter again in the tubing manufacturing technology steps, thereby form the predispersed fiber formed body, this preform can be drawn into optical fiber, and this optical fiber has the pure silica core zone of the clad zone encirclement in the involved hole according to the present invention.

In any embodiment as herein described, the final fixed predispersed fiber formed body 50 of gained can be drawn into optical fiber in the following manner: described preform is placed in the draw machines shown in Figure 9 52, then with conventional method and apparatus heating and drawing optical fiber 54.Then optical fiber 54 is cooled off in cooling chamber 55, and measure final diameter with noncontacting pickup 56.Can use coating device 58 (also being conventional equipment) to apply one or more layers coating and curing.In pulling process, described optical fiber 54 passes through tension force assembly 60, thereby applies tension force, by described preform 50 drawing optical fibers 54.By the described tension force of opertaing device 61 controls, remain on predetermined set point with diameter with optical fiber.At last, the optical fiber 54 after will applying with feed head 62 is wrapped on the fiber optic storage bobbin 64.

Also can be used to the fixed tubing that comprises the hole is drawn again in conjunction with the described same procedure that is used for forming the core billot of Fig. 3 above.This drawing again can be used to change the size in the hole that comprises in the described tubing.For example, when the preform that comprises the hole was drawn again, diameter reduced severely more, and then the hole size in this preform will be more little.

By using the concretion technology in generation as herein described hole, we have made optical fiber, this optical fiber is made up of core zone with first refractive index and the clad zone with second refractive index, described second refractive index is lower than first refractive index in core zone, make transmission remain on in-core substantially by the light of described optical fiber, make described hole be positioned at wherein, form the clad of described optical fiber, the hole area percent in described hole is non-vanishing substantially.

By using the techniques described herein, can make a kind of optical fiber, wherein at the power mark of light greater than the full-size in any hole within 80% the zone light wavelength less than the transmission that will be used for the telecommunication automation application.So-called full-size is illustrated in the vertical cross-section of optical fiber end on observation the maximum gauge in any specific hole.For example, people have made such optical fiber, wherein in the zone of power mark greater than 80% (more preferably greater than 90%) of light, the full-size in all described holes is less than 5 microns, be more preferably less than 2 microns, be more preferably less than 1 micron, most preferably less than 0.5 micron.

Have the optical fiber that contains the zone, hole by using the techniques described herein, can making, wherein regional hole area percent is greater than 1%, more preferably greater than 10%, most preferably greater than 30%.

Said method mainly is confined to make the silicon dioxide core fibre, promptly has the optical fiber in the purer silica core district of the coating district encirclement that is contained the hole.Perhaps, if desired, can use the adulterant (using separately or common the use) of regulating refractive index, further to regulate the refractive index of core with respect to the refractive index of clad.For example, in such preferred implementation, as initial rod, preferably use above-mentioned OVD deposition technique to deposit other cigarette ash clad material thereon germanium core billot.It is regional fixed that described cigarette ash is coated, and forms the coating zone that comprises the hole around the silica core zone of doping germanium oxide.In another embodiment that comprises refractive index adjusting adulterant, use the silica core billot to coat the initial rod in district as cigarette ash.But, in producing the consolidation step in hole, except the dopant gas that produces the hole, also provide fluorine dopant source (SiF for example ₄Gas) with simultaneously with the fluorine described zone that contains hole of mixing.In this way, can form the zone that contains the hole that fluorine mixes in the silica core zone on every side.

Embodiment

To the present invention further be described by following examples below.

Step 1-core billot preparation: prepared the pure silicon dioxide core billot that diameter is 8 millimeters and 15 millimeters by standard OVD technology.At first with SiO ₂Cigarette ash (density is 0.5g/cc) is deposited on the removable bait rod, remove described bait rod then, the cigarette ash of gained uses the standard concretion method (in the chlorine of helium+3%, drying is 2 hours under 1000 ℃) fixed, then in the atmosphere that only contains He, downward feed rate with 6 mm/min drives by hot-zone (being equivalent to 3 ℃/minute the rate of heat addition), cigarette ash is sintered into the fixed glass test specimen in transparent no hole it downwards.This test specimen draws at 1900 ℃ of lower edge center lines under the pressure (partial vacuum) of 500 holders again, makes the hole closure of center line, obtains diameter and be the fixed silica core billot in no hole of 8 millimeters or 15 millimeters.Unless otherwise indicated, among each embodiment below, in the time of drawing optical fiber, use conventional coating (i.e. coating of Chang Gui acrylic acid preparation and secondary coating) that described optical fiber is applied.

Embodiment 1:

Use outside vapour deposition process (promptly by on the removable aluminium oxide bait rod that is deposited on 1 meter long * 10 mm dias) deposition 3000 gram SiO ₂(density is 0.48g/cc) cigarette ash forms SiO ₂The cigarette ash test specimen.Remove described aluminium oxide bait rod then, the diameter that will be formed by the fixed silicon dioxide of pure (not mixing) is that 8 millimeters core billot inserts described SiO ₂The cigarette ash test specimen.Following then the rod assembly in the described cigarette ash is carried out sintering.This assembly is at first in the atmosphere of 97% helium and 3% chlorine, dry down at 1000 ℃, then with this assemblies of speed drive of 32 mm/min in 100% nitrogen sintering atmosphere, be set in 1500 ℃ hot-zone by (making the intensification of preform be about 16 ℃/minute).Described then preform assembly drives (for the second time promptly) once more downwards, speed (the preform rate of heat addition is about 12.5 ℃/minute) with 25 mm/min is passed through the hot-zone, at last carry out last sintering, coat test specimen with the outside that described cigarette ash is sintered into inoculation nitrogen (nitrogen-seeded) with the speed (about 3 ℃/minute rate of heat addition) of 6 mm/min.Use described first higher downward feed rate so that the outside of predispersed fiber formed body polishes, this helps gas entrapment within described preform.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours.

Use about 2.54 lis of hot length, be set in 2100 ℃ draw machines, with the speed of 1 meter per second the predispersed fiber formed body of gained being drawn into diameter is 125 micron fiber.The solid silica core and the clad that the sem analysis (Fig. 6) of the xsect end face of gained optical fiber have been shown about 22 micron diameters, the regional hole area % (the hole area is divided by area * 100 in the zone that contains the hole) of described clad is 3.5, mean diameter is 0.3 micron (300 nanometer), the maximum void diameter is 0.50 micron (500 nanometer), standard deviation is 0.08 micron, comprise about 3400 holes, on whole cross section of optic fibre, obtain about altogether 7900 holes.Total hole area % (area in hole is divided by the cross section of optic fibre total area * 100) of optical fiber is about 3.4%.The optical property of this optical fiber is: the multimode under 1550 nanometers decays to 2.2dB/Km, the dominant mode under 1550 nanometers decay to 0.28dB/km.

Embodiment 2:

With 3000 gram SiO ₂(density is 0.47g/cc) cigarette ash is deposited on the pure silicon dioxide core billot of 1 meter long * 8 mm dias in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly is at first following dry 2 hours at 1000 ℃ in the atmosphere of being made up of the chlorine of helium and 3%, then in the atmosphere of 70 volume % nitrogen and 30 volume % helium, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 32 mm/min, speed with 25 mm/min drives downwards by described hot-zone again then, last speed sintering with 6 mm/min, with the described cigarette ash of sintering, form the outer test specimen that covers of nitrogen/helium inoculation.Described then test specimen placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours, to discharge helium from test specimen.

According to embodiment 1 described similar mode described test specimen being drawn into diameter is 125 micron fiber.The solid silica core and the clad that the sem analysis of the end face of gained optical fiber have been shown about 22 micron diameters, it is 4.5 that the regional hole area nitrogen of described clad is filled hole %, mean diameter is 0.45 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 1.17 microns, standard deviation is 0.19 micron, comprises about 2300 holes, obtains about 8400 holes on whole cross section of optic fibre altogether.Total optical fiber hole area % (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 4.4%.In the time of according to the multimode attenuation measurement, the optical property of this optical fiber under 1550 nanometers is 9.8dB/Km.

Embodiment 3:

With 3000 gram SiO ₂(density is 0.46g/cc) cigarette ash is deposited on the pure silicon dioxide core billot from 1 meter long * 8 mm dias of step 1 in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly at first in the atmosphere of forming by the helium of 3% chlorine and surplus 1000 ℃ dry 2 hours down, then in the atmosphere of 50 volume % nitrogen and 50 volume % helium, drive hot-zone downwards by being set in 1500 ℃ with the speed of 32 mm/min.This assembly drives downwards by identical hot-zone once more with the speed of 25 mm/min then, then with the speed of 6 mm/min once more by identical hot-zone to carry out last sintering, with the described cigarette ash of sintering, form the outer test specimen that covers of nitrogen/helium inoculation.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours, from the preform test specimen, to discharge helium.

According to embodiment 1 described similar mode described test specimen being drawn into diameter is 125 micron fiber.The solid silica core and the clad that the sem analysis of the end face of gained optical fiber have been shown 22 micron diameters, regional hole area (nitrogen) % of described clad is 2.6, mean diameter is 0.42 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 0.80 micron, standard deviation is 0.14 micron, comprises about 2300 holes, obtains about 5700 holes on whole cross section of optic fibre altogether.Total optical fiber hole area % (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 2.5%.In the time of according to the multimode attenuation measurement, the optical property of this optical fiber under 1550 nanometers is 11.9dB/Km.

Embodiment 4:

With 3000 gram SiO ₂(density is 0.40g/cc) cigarette ash is deposited on the pure silicon dioxide core billot from 1 meter long * 8 mm dias of step 1 in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly at first descended dry 2 hours at 1000 ℃ in the atmosphere of being made up of the chlorine of helium and 3%, then in the atmosphere of 30 volume % nitrogen and 70 volume % helium, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 32 mm/min.This assembly drives downwards by identical hot-zone once more with the speed of 25 mm/min then, then with the speed of 6 mm/min once more by identical hot-zone to carry out last sintering, with the described cigarette ash of sintering, form the outer test specimen that covers of nitrogen/helium inoculation.In the described then maintenance heating furnace that test specimen is placed the argon purge that is set in 1000 ℃ 24 hours, from test specimen, to discharge helium.

According to embodiment 1 described similar mode described test specimen being drawn into diameter is 125 micron fiber.The solid silica core and the clad that the sem analysis of the end face of gained optical fiber have been shown 22 micron diameters, regional hole area (nitrogen) % of described clad is 2.0, mean diameter is 0.37 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 0.89 micron, standard deviation is 0.13 micron, comprises about 2100 holes, obtains about 8100 holes on whole cross section of optic fibre altogether.Total optical fiber hole area % (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 2.6%.In the time of according to the multimode attenuation measurement, the optical property of this optical fiber under 1550 nanometers is 4.4dB/Km.

Embodiment 5:

With 3000 gram SiO ₂(density is 0.38g/cc) cigarette ash is deposited on the pure silicon dioxide core billot from 1 meter long * 8 mm dias of step 1 in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly at first in the atmosphere of forming by the helium of 3% chlorine and surplus 1000 ℃ dry 2 hours down, then in the atmosphere of 15 volume % nitrogen and 85 volume % helium, drive hot-zone downwards by being set in 1500 ℃ with the speed of 32 mm/min.This assembly drives downwards by identical hot-zone once more with the speed of 25 mm/min then, then with the speed of 6 mm/min once more by identical hot-zone to carry out last sintering, with the described cigarette ash of sintering, form the outer test specimen that covers of nitrogen/helium inoculation.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours, from test specimen, to discharge helium.

According to embodiment 1 described similar mode described test specimen being drawn into diameter is 125 micron fiber.The sem analysis of the end face of gained optical fiber has been shown the solid silica core and the clad of 22 micron diameters, and regional hole area (nitrogen) % of described clad is 2.0, and mean diameter is 0.37 micron, and the hole of minimum diameter is 0.03 micron.In the time of according to the multimode attenuation measurement, the optical property of this optical fiber under 1550 nanometers is 9.1dB/Km.

Embodiment 6:

With 3000 gram SiO ₂(density is 0.5g/cc) is deposited on the removable aluminium oxide bait rod of 1 meter long * 10 mm dias; After the deposition cigarette ash, remove aluminium oxide bait rod.This assembly sintering that carries out as described below then.This assembly at first in the atmosphere of forming by the helium of 3% chlorine and surplus 1000 ℃ dry 2 hours down, then in 100% nitrogen atmosphere, drive hot-zone downwards by being set in 1500 ℃ with the speed of 32 mm/min.This assembly drives downwards by identical hot-zone once more with the speed of 25 mm/min then, then with the speed of 6 mm/min once more by identical hot-zone to carry out last sintering, with the described cigarette ash of sintering, form the outer test specimen that covers of nitrogen/helium inoculation.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours, to discharge helium.To insert the SiO of nitrogen inoculation from 3 millimeters pure silicon dioxide core billot of step 1 ₂The center line of glass test specimen.

Be 125 micron fiber according to the predispersed fiber formed body of gained being drawn into diameter then with the similar mode of embodiment 1, on center line, hold in the palm the pressure tractive of (vacuum) from the test specimen top with＜250, to guarantee that in pulling process clad and core billot are complementary.The sem analysis of fiber end face is demonstrated the solid silica core and the clad of 8 micron diameters, regional hole area percent (nitrogen) of described clad is 4.0%, mean diameter is 0.33 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 0.82 micron, standard deviation is 0.14 micron, comprises about 4100 holes.The optical property of this optical fiber shows it greater than the single mode form under the wavelength of about 800 nanometers, and the decay under 850 nanometers and 1550 nanometers is respectively 4.8 and 4.5dB/Km, and the mode field diameter under 1550 nanometers is about 11 microns.This optical fiber shows high bending resistance; It has extremely low decay and increases, around the mandrel of 10 millimeters of diameters in song, the decay under 1550 nanometers only increases and to be 2-8dB (the commercially available SiO of standard by contrast, weekly ₂-GeO ₂0.35 the conventional single-mode fiber of Δ step-refraction index for identical radially bending, is about the Δ decay of 25dB weekly under 1550 nanometers).This explanation clad optical fiber that contains the hole of the present invention can have less than 40 in 1550 nanometers (i.e. the decay that is recording on the straight length deducts and rotating around mandrel the decay that records on the optical fiber of equal length of (is that 10 millimeters mandrel is reeled around diameter)), be more preferably less than 30, be more preferably less than 20, most preferably the Δ decay that produces less than the bending in 10dB/ week (i.e. decay increases).

Embodiment 7:

With 3000 gram SiO ₂(0.5g/cc density) is deposited on the billot of 1 meter long * 8 mm dias in the flame deposited mode, it has small base (pedestal), and have step-refraction index (with the billot center at a distance of 0-1.3 millimeter radius be 0.39% Δ step (step), with the billot center at a distance of 1.3-2.3 millimeter radius be 0.06% Δ pedestal, with the billot center be pure silicon dioxide at a distance of 2.3-4 millimeter radius), i.e. GeO ₂-SiO ₂Core-pedestal, SiO ₂Coat billot according to the similar method manufacturing of the billot of preparation process 1.This assembly sintering that carries out as described below then.This assembly is at first at 100% air atmosphere (～78 volume %N ₂+～21 volume %O ₂+～1 volume %Ar+～0.03 volume %CO ₂) in, kept 2 hours down at 1000 ℃, then at 100% air atmosphere (～78 volume %N ₂+～21 volume %O ₂+～1 volume %Ar+～0.03 volume %CO ₂) in, this assembly with the described cigarette ash of sintering, forms (～78 volume %N of air inoculation with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 6 mm/min ₂+～21 volume %O ₂+～1 volume %Ar+～0.03 volume %CO ₂) the outer test specimen that coats.This test specimen places be set in 1000 ℃ the maintenance heating furnace 24 hours with argon purge.

According to mode similar to Example 1 the predispersed fiber formed body of gained being drawn into diameter is 125 micron fiber.The sem analysis of fiber end face is shown it has radius and is about 22 microns no hole solid core billot and (comprises the GeO described in the top billot ₂-SiO ₂Core), it is about 39 microns coating district that contains the hole and the encirclement of hole coating ring, regional hole area percent (～78 volume %N in hole by external diameter ₂+～21 volume %O ₂+～1 volume %Ar+～0.03 volume %CO ₂) be 2.9%, mean diameter is 0.29 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 1.4 microns, it is again 125 microns the pure silicon dioxide external coating encirclement that does not contain the hole (all radial dimensions are to measure from the center of described optical fiber) by external diameter, has about 350 holes in the cross section of optic fibre altogether.Because slower downward driving and sintering rate, described hole are positioned near a certain zone, this zone is corresponding to GeO ₂-SiO ₂Core-SiO ₂The position of clad core billot when fixed extends to from the position with 22 microns of optical fiber center line radial distances that radial distance is about 39 microns on the cross section of optic fibre.Total hole area % (area in hole is divided by the total cross-sectional area of optical fiber * 100) is about 0.12%.The optical property of this optical fiber is: when as the multimode attenuation measurement time, under 850 nanometers, 1310 nanometers and 1550 nanometers, be respectively 2.94,1.58 and 1.9dB/Km, when splicing into single-mode fiber, for dominant mode, under 1310 nanometers and 1550 nanometers, be respectively 0.42 and 0.29dB/Km.

Embodiment 8:

Under 1900 ℃, in draw machines again, the fixed test specimen that embodiment 2 is made is drawn into 8 millimeters billot again.With 750 gram SiO ₂The external coating of (density is 0.54g/cc) cigarette ash is deposited in the flame deposited mode on the core billot of coating of 1 meter long * 8 mm dias (being the pure silicon dioxide core, by air lining (airline) clad made from 70% nitrogen+30% helium in embodiment 2).This assembly sintering that carries out as described below then.This assembly at first descended dry 2 hours at 1000 ℃ in the atmosphere of being made up of the chlorine of helium and 3%, then in the atmosphere of 100% helium, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 6 mm/min.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours, so that helium is discharged from test specimen.The outer coating part that is positioned at the clad region exterior that comprises the hole is the fixed glass in no hole that does not contain the hole.

According to embodiment 1 described similar mode described test specimen being drawn into diameter is 125 micron fiber.The solid silica core that the sem analysis of the end face of gained optical fiber has been shown about 4 microns radiuses, it is about 18 microns the nearly clad zone encirclement that contains the air lining by radius, zone hole area % (nitrogen) is 2.9%, 0.45 micron of mean diameter, the minimum diameter hole is 0.03 micron, maximum gauge is 1.26 microns, and standard deviation is 0.19 micron, comprises about 300 holes.The described outer coating part that contains the outside, coating zone of air lining is the fixed glass in no hole (all radial dimensions are measured from the center) that does not contain the hole.Total optical fiber hole area % (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 3.4%.This optical fiber decays to 10.5dB/Km in the multimode of 1550 nanometers.

Embodiment 9:

With 7000 gram SiO ₂(density is 0.5g/cc) is deposited on (0.35% Δ, 0.33 core/clad diameter ratio) 1 meter long * 22 mm dias, that have step-refraction index GeO in the flame deposited mode ₂-SiO ₂Core-SiO ₂On the clad billot method of billot of preparation process 1 (be similar to be used for).This assembly sintering that carries out as described below then.This assembly at first descended dry 2 hours at 1000 ℃ in the atmosphere of being made up of the chlorine of helium and 3%, then in the atmosphere of 2 volume %CO+98 volume % helium, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 32 mm/min.This assembly is with the speed of 25 mm/min then, drive downwards once more by identical hot-zone and sintering atmosphere, described then assembly drives downwards by identical hot-zone and sintering atmosphere once more with the speed of 6 mm/min, with the described cigarette ash of sintering, forms the outer coating test specimen of CO/ helium inoculation.This test specimen is placed be set in 1000 ℃ the maintenance heating furnace 24 hours with argon purge.

It is 125 micron fiber that the predispersed fiber formed body of gained is drawn into diameter according to mode similar to Example 1.Sem analysis to optical fiber connector shows that it has the solid core and the internal coating (GeO of 8 micron diameters of 24 microns of diameters ₂-SiO ₂Core, the SiO of 24 micron diameters ₂Internal coating), and external coating, the regional hole area % (CO) of described external coating is 1.8%, mean diameter is 0.41 micron, and the minimum diameter hole is 0.03 micron, and maximum gauge is 0.84 micron, standard deviation is 0.21 micron, comprises about 1100 holes.The optical property of this optical fiber is when as the porous attenuation measurement time, to be respectively 1.95 in 850,1310 and 1550 nanometers, 1.44 and 0.72dB/Km, when splicing into single-mode fiber, when measuring the dominant mode of this optical fiber, be respectively 0.30 and 0.43dB/Km in 1310 nanometers and 1550 nanometers.

Embodiment 10:

With 3000 gram SiO ₂(density is 0.4g/cc) is deposited on the removable aluminium oxide bait rod of 1 meter long * 10 mm dias; After the deposition cigarette ash, remove described aluminium oxide bait rod.This assembly sintering that carries out as described below then.At first in the atmosphere of helium+3% chlorine, drying is 2 hours under 1000 ℃, then at 100%CF for this assembly ₄Atmosphere in, drive hot-zone downwards with the speed of 32 mm/min by being set in 1500 ℃.This assembly drives downwards by identical hot-zone and atmosphere once more with the speed of 25 mm/min then, and this assembly drives downwards by identical hot-zone and atmosphere to carry out last sintering once more with the speed of 6 mm/min then, sinters described cigarette ash into CF ₄(and/or CF ₄The reaction product of-gas and silicon dioxide comprises CO and CO ₂The outer coating test specimen of)-inoculation.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.

According to mode similar to Example 1 the predispersed fiber formed body of gained being drawn into diameter then is 125 micron fiber, and difference is, keeps the back pressure of about 850 holder positive pressure of nitrogen power on center line, and is open with the hole in the middle of keeping.Sem analysis to fiber end face shows 125 micron fiber, and its hole with 28 microns of diameters also has clad as core, the regional hole area % (CF of described clad ₄/ CO/CO ₂) be 2.8%, mean diameter is 0.67 micron, and the hole of minimum diameter is 0.17 micron, and maximum gauge is 1.4 microns, and standard deviation is 0.26 micron, comprises about 700 holes.

Embodiment 11:

In draw machines again, under 1900 ℃, the fixed test specimen that makes among the embodiment 2 is drawn into 8 millimeters billot again.With 750 gram SiO ₂The external coating of (density is 0.56g/cc) cigarette ash is deposited on the pure silicon dioxide core, air lining clad (in embodiment 17, making by 100% nitrogen) billot of 1 meter long * 8 mm dias in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly at first in the atmosphere of helium+3% chlorine, 1000 ℃ dry 2 hours down, then in 100 volume % nitrogen atmospheres, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 32 mm/min, speed with 25 mm/min drives downwards once more by described hot-zone then, carry out last sintering with the speed of 6 mm/min then, with the described cigarette ash of sintering, form the outer coating test specimen of nitrogen/helium inoculation.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.

According to mode similar to Example 1 described test specimen being drawn into diameter is 125 micron fiber.Scanning electron microscopy picture analysis to fiber end face shows that the about 4 microns solid silica core zone of radius is surrounded by the about 16 microns contiguous clad zone, hole that contains of external diameter, it comprises the hole (nitrogen) of about 11.6 volume %, mean void diameter is 0.70 micron, it is that 125 microns the hole silicon dioxide external coating of containing surrounds (all radial dimensions all are to measure from fiber optic hub) by external diameter, it comprises the hole (nitrogen) of 4.7 volume %, mean void diameter is 0.54 micron, the minimum diameter hole is 0.03 micron, maximum gauge is 0.87 micron, and standard deviation is 0.23 micron.This is proof just, can form different hole content with respect to fiber radius, therefore can obtain the refractive index curve of the varying level of different holes percentage.Record as multimode decay, the optical property of this optical fiber is for being 17.4dB/Km in 1550 nanometers.

Embodiment 12:

With 500 gram SiO ₂(density is 0.46g/cc) cigarette ash is deposited on the pure silicon dioxide core billot of 1 meter long * 15 mm dias in the flame deposited mode.This assembly sintering that carries out as described below then.At first in the atmosphere of helium+3% chlorine, drying is 2 hours under 1000 ℃, then at 70 volume % nitrogen+30 volume %CF for this assembly ₄Atmosphere in, drive hot-zone downwards with the speed of 32 mm/min by being set in 1500 ℃.This assembly drives downwards by identical hot-zone and atmosphere once more with the speed of 25 mm/min then, this assembly drives downwards by identical hot-zone and atmosphere to carry out last sintering once more with the speed of 6 mm/min then, described cigarette ash is sintered into the outer coating test specimen of F doping+nitrogen inoculation.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.

According to mode similar to Example 1 described test specimen being drawn into diameter is 125 micron fiber.The optical imagery analysis of 200 times of amplifications that fiber end face is carried out and 500 times shows about 82 microns solid silica core and the clad of diameter, described clad comprises the hole (nitrogen) of about 9.0 volume %, mean void diameter is 0.73 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 2.0 microns, standard deviation is 0.40 micron, comprises about 1200 holes.When as the multimode attenuation measurement time, the optical property of this optical fiber is for being respectively 16.1,14.5 and 13.2dB/Km in 850 nanometers, 1310 nanometers and 1550 nanometers.When described optical fiber is that 5 millimeters mandrel is reeled under the situation of a circle around radius, the decay increase that the optics bend performance data is presented at 850 and 1550 nanometers is respectively 1.85 and 0.67dB.Having made does not have the reference in hole optical fiber, uses SiF when coating ₄+ He sintering atmosphere obtains not having the optical fiber in hole.The crooked character of the optics of this reference optical fiber is: when described optical fiber is that 5 millimeters mandrel is reeled under the situation of a circle around radius, the decay increase that the optics bend performance data is presented at 850 and 1550 nanometers is respectively 8.06 and 9.33dB.These presentation of results, the optical fiber that comprises the hole in the clad has good bending property.

Embodiment 13:

With 500 gram SiO ₂(density is 0.53g/cc) cigarette ash is deposited on the GeO of 1 meter long * 15 mm dias in the flame deposited mode ₂-SiO ₂On the graded index solid glass billot (have parabola shaped index distribution, the Δ refractive index is 2% (with respect to silicon dioxide) on the peak).This assembly sintering that carries out as described below then.At first in the atmosphere of helium+3% chlorine, drying is 2 hours under 1000 ℃ for this assembly, then in 100% nitrogen atmosphere, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 32 mm/min.This assembly drives downwards by identical hot-zone and atmosphere once more with the speed of 25 mm/min then, this assembly carries out last sintering with the speed of 6 mm/min in 100% nitrogen then, with the described cigarette ash of sintering, form the outer coating test specimen of nitrogen inoculation.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.

According to mode similar to Example 1 described test specimen being drawn into diameter then is 125 microns test specimen.The optical imagery analysis of 200 times of amplifications that fiber end face is carried out and 500 times shows, have diameter and be about the silica core and the clad of 81 microns solid Germania-doped, described clad comprises the hole (nitrogen) of about 3.5 volume %, mean void diameter is 0.46 micron, the hole of minimum diameter is 0.04 micron, maximum gauge is 0.97 micron, and standard deviation is 0.16 micron, comprises about 1500 holes.When as the multimode attenuation measurement time, the optical property of described optical fiber is, is respectively 3.36,1.09 and 0.84dB/Km under 850 nanometers, 1310 nanometers and 1550 nanometers.When described optical fiber is that 5 millimeters mandrel is reeled under the situation of a circle around radius, the optics bend performance data is presented at the decay increase of 850 and 1550 nanometers respectively less than 0.70dB and 0.55dB.62.5 microns commercially available core (GeO have been measured ₂-SiO ₂Graded index (have parabola shaped index distribution, the Δ refractive index is 2% (with respect to silicon dioxide) on the peak)), diameter is the bending resistance of 125 microns no hole reference optical fiber.When described optical fiber is that 5 millimeters mandrel is reeled under the situation of a circle around radius, the decay increase that the optics bend performance data is presented at 850 and 1550 nanometers is respectively 1.13 and 1.20dB.The optical fiber that comprises the hole in these presentation of results clads has good bending property.

Embodiment 14:

With 1200 gram SiO ₂(density is 0.47g/cc) cigarette ash is deposited on the GeO of 1 meter long * 15 mm dias in the flame deposited mode ₂-SiO ₂On the graded index solid glass billot (have parabola shaped index distribution, the Δ refractive index is 2% (with respect to silicon dioxide) on the peak).This assembly sintering that carries out as described below then.At first in the atmosphere of helium+3% chlorine, drying is 2 hours under 1000 ℃ for this assembly, then in 100% oxygen atmosphere, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 32 mm/min.This assembly drives downwards by identical hot-zone and atmosphere once more with the speed of 25 mm/min then, this assembly carries out last sintering with the speed of 6 mm/min again in 100% oxygen then, with the described cigarette ash of sintering, form the outer coating test specimen of oxygen inoculation.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.

According to mode similar to Example 1 described test specimen being drawn into diameter then is 125 microns test specimen.The optical imagery analysis of 200 times of amplifications that fiber end face is carried out and 500 times shows, have about 62.5 microns solid silicon dioxide-germanium oxide core and the clad of diameter, described clad comprises the hole (oxygen) of about 9.0 volume %, mean void diameter is 0.45 micron, the hole of minimum diameter is 0.03 micron, maximum gauge is 1.2 microns, and standard deviation is 0.21 micron, comprises about 400 holes.When as the multimode attenuation measurement time, the optical property of described optical fiber is, is respectively 3.00,0.74 and 0.45dB/Km under 850 nanometers, 1310 nanometers and 1550 nanometers.When described optical fiber is that 5 millimeters mandrel is reeled under the situation of a circle around radius, the optics bend performance data is presented at the decay increase of 850 and 1550 nanometers respectively less than 0.03dB and 0.01dB.62.5 microns commercially available core (GeO have been measured ₂-SiO ₂Graded index (have parabola shaped index distribution, the Δ refractive index is 2% (with respect to silicon dioxide) on the peak)), the bending resistance of the no hole reference optical fiber of 125 microns of diameters.When described optical fiber is that 5 millimeters mandrel is reeled under the situation of a circle around radius, the decay increase that the optics bend performance data is presented at 850 and 1550 nanometers is respectively 1.13 and 1.20dB.The optical fiber that comprises the hole in these presentation of results clads has good bending property.Bandwidth measurement (overfill excitation (overfill launch)) result is, at 850nm=200MHz*km, at 1300nm=500MHz*km.This embodiment has illustrated in 1550 nanometers to be the optical fiber of the micro-structural of multimode.This optical fiber comprises core zone with first refractive index and the clad zone with second refractive index, described second refractive index is lower than first refractive index in core zone, make the light that will transmit remain on in-core substantially, comprise the zone that at least one comprises the hole that a large amount of aperiodicity are provided with in the described clad by described optical fiber.This optical fiber is multimode under 1550 nanometers preferably, and when the mandrel that around radius is 5 millimeters was reeled a week, the decay under 1550 nanometers increased less than 1dB/km, is more preferably less than 0.75, most preferably less than 0.5db/km.

Embodiment 15:

Have long 8 inches be set in 2000 ℃ the stove of hot-zone, with the speed of 3 meter per seconds embodiment 8 described predispersed fiber formed bodies being drawn into diameter is 125 micron fiber.The sem analysis of fiber end face is shown that radius is about 4 microns solid silica core by the about 18 microns contiguous clad zone encirclement that contains the air lining of radius, its regional hole area % (nitrogen is filled) is 8.5%, mean void diameter is 0.63 micron, minimum void diameter is 0.03 micron, maximum gauge is 1.9 microns, standard deviation is 0.32 micron, and it is again 125 microns the pure silicon dioxide external packets coating encirclement that does not contain the hole (all radial dimensions all are to measure from the center of optical fiber) by external diameter.The regional hole area percent (nitrogen) of the optical fiber that draws among the embodiment 8 only is 2.9%, and mean diameter is 0.45 micron; Therefore prove that draw conditions (being long hot-zone and draw rate faster this moment) can be used to control hole air filling ratio and void diameter.The outer coating part that is positioned at the outside, clad zone that contains the air lining is the fixed glass in no hole that does not contain the hole.

Embodiment 16:

With 3000 gram SiO ₂(density is 0.53g/cc) cigarette ash is deposited on the pure silicon dioxide core billot of 1 meter long * 8 mm dias in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly is at first in the atmosphere of helium+3% chlorine, drying is 2 hours under 1000 ℃, then in 100 volume % argon gas atmosphere, with the speed of 32 mm/min by being set at 1500 ℃ hot-zone, speed with 25 mm/min drives downwards once more by described hot-zone then, in argon gas, carry out last sintering with the speed of 6 mm/min then,, form the outer coating test specimen of argon gas inoculation with the described cigarette ash of sintering.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.It is 125 micron fiber that this test specimen is drawn into diameter in mode similar to Example 1.SEM has shown solid silica core and the clad that diameter is about 22 microns to the analysis of fiber end face, the regional hole area % (argon gas) of described clad is about 8.0%, mean void diameter is 0.35 micron, the minimum diameter hole is 0.03 micron, maximum gauge is 0.85 micron, and standard deviation is 0.15 micron.When as the multimode attenuation measurement time, the optical property of this optical fiber is: be respectively 1.65 and 1.20dB/Km under 1310 nanometers and 1550 nanometers.

Embodiment 17:

With 3000 gram SiO ₂(density is 0.55g/cc) cigarette ash is deposited on the pure silicon dioxide core billot of 1 meter long * 8 mm dias in the flame deposited mode.This assembly sintering that carries out as described below then.This assembly is at first in the atmosphere of helium+3% chlorine, drying is 2 hours under 1000 ℃, then in 100 volume % nitrogen atmospheres, with the speed of 32 mm/min by being set at 1500 ℃ hot-zone, speed with 25 mm/min drives downwards once more by described hot-zone then, carry out last sintering with the speed of 6 mm/min then,, form the outer coating test specimen of nitrogen inoculation with the described cigarette ash of sintering.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃.It is 125 micron fiber that this test specimen is drawn into diameter in mode similar to Example 1.SEM has shown that to the analysis of fiber end face diameter is about 22 microns solid silica core and clad, the regional hole area % (nitrogen) of described clad is 2.0%, mean diameter is 0.22 micron, the minimum diameter hole is 0.03 micron, maximum gauge is 0.50 micron, and standard deviation is 0.08 micron.When as the multimode attenuation measurement time, the optical property of this optical fiber is: be respectively 1.28 and 0.87dB/Km under 1310 nanometers and 1550 nanometers, when this optical fiber splices into single-mode fiber, measure the dominant mode of this optical fiber, under 1550 nanometers 0.28dB/Km.

Embodiment 18:

With 4600 gram SiO ₂(density is 0.42g/cc) cigarette ash is deposited on (0.35% Δ, 0.33 core/clad diameter ratio) 1 meter long * 10 mm dias, that have step-refraction index GeO in the flame deposited mode ₂-SiO ₂Core-SiO ₂On the clad billot method of billot of preparation process 1 (be similar to be used for).This assembly sintering that carries out as described below then.This assembly is at first following dry 2 hours at 1000 ℃ in the atmosphere of being made up of the chlorine of helium and 3%, then in the atmosphere of 100 volume % oxygen, with the downward hot-zone that drives by being set in 1500 ℃ of the speed of 6 mm/min,, form the outer coating test specimen of oxygen inoculation with the described cigarette ash of sintering.This test specimen is placed be set in 1000 ℃ the maintenance heating furnace 24 hours with argon purge, so that helium is discharged from described test specimen.

The predispersed fiber formed body of gained is with the speed of 18 meter per seconds, and being drawn into diameter in the stove with 8 inches long hot-zones that are set in 2000 ℃ is 125 micron fiber.It is 125 micron fiber that this test specimen is drawn into diameter in mode similar to Example 15.Sem analysis to fiber end face shows that it has radius and is about 4 microns GeO ₂-SiO ₂The central core zone, it is surrounded by contiguous clad zone, the about 12 microns no hole of external radius, the latter is about 18 microns the clad zone that contains the hole by external radius again and surrounds, and described radius to be about 18 microns the clad zone that contains the hole be that the pure silicon dioxide clad in 125 microns no hole surrounds (all radial dimensions are all measured from fiber optic hub) by overall diameter.The described regional hole area % of ring zone in this zone that contains the hole is the 4.2% (O of 100 volume % ₂), mean diameter is 0.53 micron, and the hole of minimum diameter is 0.18 micron, and maximum gauge is 1.4 microns, and the hole sum is about 85 in the cross section of optic fibre.Because slower downward driving and sintering rate, the position in hole is adjacent with a certain zone, and described zone is corresponding to GeO ₂-SiO ₂Core-SiO ₂Clad core billot is in the position of consolidation process, on cross section of optic fibre from radially extending to about 18 microns radial distance at a distance of 12 microns position with the optical fiber center line.Total optical fiber hole area % (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 0.21%.The optical property of this optical fiber is: be respectively 0.34 and 0.21dB/Km under 1310 and 1550 nanometers, fiber cutoff (fiber cutoff) shows that this optical fiber is the single mode form when being higher than 1230 nanometers, make optical fiber be the single mode form under the wavelength that is higher than 1230 nanometers.A part of measuring this optical fiber is the bending property of 10 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about the 0.7dB/ circle, thereby the method that proof uses the present invention to disclose is that 10 millimeters mandrel even the decay that can be less than the 5dB/ circle increase around diameter.The same section of having measured optical fiber is the bending property of 20 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about the 0.08dB/ circle, therefore proof is used method of the present invention, when being 20 millimeters mandrel around diameter, decay increases and can enclose less than 1dB/, is more preferably less than the 0.5dB/ circle.

Embodiment 19

Restrain SiO by OVD with 290 ₂(density is 0.47g/cc) smoke deposition is at (0.35% Δ, 0.33 core/clad diameter ratio) 1 meter long fixed fully * 10.4 mm dias, that have step-refraction index GeO ₂-SiO ₂Core-SiO ₂On the clad core billot, thereby make a kind of preform, this preform comprises fixed core zone, and this core zone is surrounded by fixed coated with silica zone, and the latter is surrounded by the cigarette ash silicon dioxide region again.Cigarette ash clad to this assembly as described below then carries out sintering.This assembly is at first in the atmosphere of helium and 3% chlorine, drying is 2 hours under 1000 ℃, speed with 200 mm/min drives this assembly downwards in 100% oxygen sintering atmosphere then, by being set in 1490 ℃ hot-zone (making that the heating rate of cigarette ash preform outside is about 100 ℃/minute in the process that drives downwards).Described then preform assembly drives (for the second time promptly) once more downwards, with the speed of 100 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 50 ℃/minute in the process of downward driving).Then, described preform assembly drives (for the third time promptly) once more downwards, with the speed of 50 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 25 ℃/minute in the process of driving downwards).Then, described preform assembly drives (promptly the 4th time) once more downwards, with the speed of 25 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 12.5 ℃/minute in the process of downward driving).Then, (about 3 ℃/minute rate of heat addition) carries out last sintering under the speed of 6 mm/min, coats test specimen with the outside that described cigarette ash is sintered into inoculation oxygen.Utilize the higher downward feed rate of described first series that the outside of predispersed fiber formed body is polished, this helps gas entrapment within described preform.Then, described test specimen is placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours.Then described preform is put back in the lathe, deposited the other SiO of 3600 grams again by OVD therein ₂(density is 0.42g/cc) cigarette ash.Then, the cigarette ash sintering that carries out as described below that is used for this clad of this assembly (can be described as the external packets coating).This assembly is at first in the atmosphere of 97% helium and 3% chlorine, drying is 2 hours under 1000 ℃, then in the atmosphere of 100 volume % helium, drive it downwards by being set in 1500 ℃ hot-zone with the speed of 6 mm/min, with the described cigarette ash of sintering, no hole core, silicon dioxide that formation contains germanium oxide do not have the inner clad in hole, silicon dioxide oxygen oese (silicon dioxide that promptly has oxygenous hole), and the outside coating test specimen that does not contain the hole.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃, so that argon gas is discharged from test specimen.Having 8 inches long be arranged in 2000 ℃ the stove of hot-zone, under the speed of 20 meter per seconds, described predispersed fiber drip molding is drawn into diameter and is about 125 micron fiber then.Sem analysis to fiber end face shows that it has radius and is about 4 microns GeO ₂-SiO ₂Core, this core is 12 microns no hole contiguous clad zone encirclement by outer radius, the latter is again 18 microns the clad zone that contains the hole (about 6 microns of ring thickness) encirclement by outer radius, and described outer radius is that 18 microns the clad zone that contains the hole is about 125 microns no hole pure silicon dioxide external packets coating encirclement (all radial dimensions all are to measure from the center of optical fiber) again by outer dia.Regional hole area percent is 2.7% (oxygen of 100 volume %) in the described ring zone that contains the hole, and mean diameter is 0.36 micron, and the minimum diameter hole is 0.05 micron, and maximum gauge is 0.8 micron, total total about 105 holes in cross section of optic fibre.The total hole of optical fiber area percent (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 0.1%.The optical property of this optical fiber is: be respectively 0.33 and 0.19dB/Km in 1310 and 1550 nanometers, fiber cut off wavelength is about 1250 nanometers, makes this optical fiber be the single mode form under the wavelength that is higher than 1250 nanometers.A part of measuring this optical fiber is the bending property of 10 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about 0.2dB/ encloses, thereby proof is 10 millimeters mandrel even can be less than the decay increase that 1dB/ encloses, preferably encloses less than 0.5dB/ around diameter.The same section of having measured optical fiber is the bending property of 20 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about the 0.02dB/ circle, therefore proof is when being 20 millimeters mandrel around diameter, decay increases and can enclose less than 1dB/, be more preferably less than the 0.1dB/ circle, be more preferably less than the 0.05dB/ circle.The same section of having measured optical fiber is the bending property of 6 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about the 2dB/ circle, therefore proof is when being 6 millimeters mandrel around diameter, decay increases and can enclose less than 10dB/, be more preferably less than the 5dB/ circle, be more preferably less than the 3dB/ circle.

Embodiment 20

Restrain SiO by OVD with 450 ₂(density is 0.37g/cc) smoke deposition is at (0.35% Δ, 0.33 core/clad diameter ratio) 1 meter long fixed fully * 22 mm dias, that have step-refraction index GeO ₂-SiO ₂Core-SiO ₂On the clad core billot, thereby make a kind of preform, this preform comprises fixed core zone, and this core zone is surrounded by fixed coated with silica zone, and the latter is surrounded by the cigarette ash silicon dioxide region again.Cigarette ash clad to this assembly as described below then carries out sintering.This assembly is at first in the atmosphere of helium and 3% chlorine, drying is 2 hours under 1000 ℃, speed with 200 mm/min drives this assembly downwards in 100% nitrogen sintering atmosphere then, by being set in 1490 ℃ hot-zone (making that the heating rate of cigarette ash preform outside is about 100 ℃/minute in the process that drives downwards).Then, described preform assembly drives (for the second time promptly) once more downwards, with the speed of 100 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 50 ℃/minute in the process of downward driving).Then, described preform assembly drives (for the third time promptly) once more downwards, with the speed of 50 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 25 ℃/minute in the process of driving downwards).Then, described preform assembly body drives (promptly the 4th time) once more downwards, speed with 25 mm/min (makes in the process that drives downwards by the hot-zone, the heating rate of cigarette ash preform outside is about 12.5 ℃/minute), (about 3 ℃/minute rate of heat addition) carries out last sintering under the speed of 6 mm/min then, coats test specimen with the outside that described cigarette ash is sintered into inoculation nitrogen.Utilize the higher downward feed rate of described first series that the outside of predispersed fiber formed body is polished, this helps gas entrapment within described preform.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours.Then in draw machines again, under 1900 ℃ temperature, this test specimen is drawn into diameter again and is 13 millimeters billot.The billot of 1 meter long * 13 mm dias that step is before made is put back in the lathe, deposits the other SiO of 4700 grams again by OVD therein ₂(density is 0.37g/cc) cigarette ash.Then, the cigarette ash sintering that carries out as described below that is used for this clad of this assembly (can be described as the external packets coating).This assembly is at first in the atmosphere of 97% helium and 3% chlorine, drying is 2 hours under 1000 ℃, then in the atmosphere of 100 volume % helium, drive it downwards by being set in 1500 ℃ hot-zone with the speed of 6 mm/min, with the described cigarette ash of sintering, no hole core, silicon dioxide that formation contains germanium oxide do not have the inner clad in hole, silicon dioxide nitrogen oese (silicon dioxide that promptly has the hole that contains nitrogen), and the outside coating test specimen that does not contain the hole.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃, so that argon gas is discharged from test specimen.Having 8 inches long be arranged in 2000 ℃ the stove of hot-zone, under the speed of 10 meter per seconds, described predispersed fiber drip molding is drawn into diameter and is about 125 micron fiber then.To the optical fiber image analysis showed of fiber end face, it has radius and is about 4 microns GeO ₂-SiO ₂Core, this core is 12 microns no hole contiguous clad zone encirclement by outer radius, the latter is again 15 microns the clad zone that contains the hole (ring thickness is about 3 microns) encirclement by outer radius, and described outer radius is that 15 microns the clad zone that contains the hole is about 125 microns no hole pure silicon dioxide external packets coating encirclement (all radial dimensions all are to measure from the center of optical fiber) again by outer dia.In the described ring zone that contains the hole, regional hole area percent is about 3% (nitrogen of 100 volume %), and mean diameter is 0.2 micron.The total hole of optical fiber area percent (the hole area is divided by the total cross-sectional area of optical fiber * 100) is about 0.1%.The optical property of this optical fiber is: be respectively 0.34 and 0.196dB/Km in 1310 and 1550 nanometers, fiber cut off wavelength is about 1290 nanometers, makes this optical fiber be the single mode form under the wavelength that is higher than 1290 nanometers.A part of measuring this optical fiber is the bending property of 10 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about 0.11dB/ encloses, thereby proof is 10 millimeters mandrel even can be less than the decay increase that 1dB/ encloses, preferably encloses less than 0.5dB/ around diameter.The same section of having measured optical fiber is the bending property of 20 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about the 0.016dB/ circle, therefore proof is when being 20 millimeters mandrel around diameter, decay increases and can enclose less than 1dB/, be more preferably less than the 0.1dB/ circle, be more preferably less than the 0.05dB/ circle.

Embodiment 21

Restrain SiO by OVD with 130 ₂(density is 0.37g/cc) smoke deposition is at (0.35% Δ, 0.33 core/clad diameter ratio) 1 meter long fixed fully * 10.5 mm dias, that have step-refraction index GeO ₂-SiO ₂Core-SiO ₂On the clad core billot, thereby make a kind of preform, this preform comprises fixed core zone, and this core zone is surrounded by fixed coated with silica zone, and the latter is surrounded by the cigarette ash silicon dioxide region again.Cigarette ash clad to this assembly as described below then carries out sintering.This assembly is at first in the atmosphere of helium and 3% chlorine, drying is 2 hours under 1000 ℃, speed with 200 mm/min drives this assembly downwards in 100% argon gas sintering atmosphere then, by being set in 1490 ℃ hot-zone (making that the heating rate of cigarette ash preform outside is about 100 ℃/minute in the process that drives downwards).Then, described preform assembly drives (for the second time promptly) once more downwards, with the speed of 100 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 50 ℃/minute in the process of downward driving).Then, described preform assembly drives (for the third time promptly) once more downwards, with the speed of 50 mm/min by hot-zone (making that the heating rate of cigarette ash preform outside is about 25 ℃/minute in the process of driving downwards).Then, described preform assembly drives (promptly the 4th time) once more downwards, speed with 25 mm/min (makes in the process that drives downwards by the hot-zone, the heating rate of cigarette ash preform outside is about 12.5 ℃/minute), (about 3 ℃/minute rate of heat addition) carries out last sintering under the speed of 6 mm/min then, coats test specimen with the outside that described cigarette ash is sintered into the inoculation argon gas.Utilize the higher downward feed rate of described first series that the outside of predispersed fiber formed body is polished, this helps gas entrapment within described preform.Then described test specimen was placed in the maintenance heating furnace of the argon purge that is set in 1000 ℃ 24 hours.Then described preform is put back in the lathe, deposited the other SiO of 5000 grams again by OVD therein ₂(density is 0.44g/cc) cigarette ash.Then, the cigarette ash sintering that carries out as described below that is used for this clad of this assembly (can be described as the external packets coating).This assembly is at first in the atmosphere of 97% helium and 3% chlorine, drying is 2 hours under 1000 ℃, then in the atmosphere of 100 volume % helium, drive it downwards by being set in 1500 ℃ hot-zone with the speed of 6 mm/min, with the described cigarette ash of sintering, no hole core, silicon dioxide that formation contains germanium oxide do not have the inner clad in hole, silicon dioxide argon gas oese (silicon dioxide that promptly has the hole that contains argon gas), and the outside coating test specimen that does not contain the hole.Then this test specimen is placed the maintenance heating furnace 24 hours of the argon purge that is set in 1000 ℃, so that argon gas is discharged from test specimen.Having 8 inches long be arranged in 2000 ℃ the stove of hot-zone, under the speed of 20 meter per seconds, described predispersed fiber drip molding is drawn into diameter and is about 125 micron fiber then.Optical fiber image analysis showed to fiber end face, it has the about 4 microns GeO2-SiO2 core of radius, this core is 12 microns no hole contiguous clad zone encirclement by outer radius, the latter is again 16 microns the clad zone that contains the hole (ring thickness is about 4 microns) encirclement by outer radius, and described outer radius is that 16 microns the clad zone that contains the hole is about 125 microns no hole pure silicon dioxide external packets coating encirclement (all radial dimensions all are to measure from the center of optical fiber) again by outer dia.Comprise argon gas, about 0.3 micron of the mean diameter in hole in the described ring zone that contains the hole.The optical property of this optical fiber is: be respectively 0.37 and 0.226dB/Km in 1310 and 1550 nanometers, fiber cut off wavelength is about 1270 nanometers, makes this optical fiber be the single mode form under the wavelength that is higher than 1270 nanometers.A part of measuring this optical fiber is the bending property of 10 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about 0.27dB/ encloses, thereby proof is 10 millimeters mandrel even can be less than the decay increase that 1dB/ encloses, preferably encloses less than 0.5dB/ around diameter.The same section of having measured optical fiber is the bending property of 20 millimeters mandrel around diameter, the decay increase of optical fiber under 1550 nanometers is about the 0.026dB/ circle, therefore proof is when being 20 millimeters mandrel around diameter, decay increases and can enclose less than 1dB/, be more preferably less than the 0.1dB/ circle, be more preferably less than the 0.05dB/ circle.

Comparative example:

Prepared test specimen according to mode similar to Example 1, difference is to carry out sintering in the atmosphere that only contains helium.This assembly at first in the atmosphere of helium+3% chlorine, 1000 ℃ dry 2 hours down, then in 100% helium atmosphere, drive described assembly downwards by being set in 1500 ℃ hot-zone with the speed of 32 mm/min.Then this assembly with the speed of 25 mm/min by identical hot-zone and atmosphere, then this assembly with the speed of 6 mm/min once more by identical hot-zone and atmosphere to carry out last sintering.Expect as us, find that described coating glass does not contain seed.This test specimen is placed 24 hours to discharge helium in being set in 1000 ℃ the maintenance heating furnace of argon purge.According to mode similar to Example 1 described test specimen is drawn into 125 micron fiber then, finds that it does not contain hole (as expection).Record the long optical fiber of 2.4Km by time cutting method (cutback method) and can't transmit light (illustrating that decay is greater than 100dB/Km); This is among expecting, because do not have refractive index difference between core and clad.

Comparative example:

Prepared test specimen according to mode similar to Example 1, difference is to carry out sintering in the atmosphere that only contains helium.This assembly at first in the atmosphere of helium+3% chlorine, 1000 ℃ dry 2 hours down, then in 100% helium atmosphere, drive described assembly downwards by being set in 1500 ℃ hot-zone with the speed of 32 mm/min.Then this assembly with the speed of 25 mm/min by identical hot-zone and atmosphere, then this assembly with the speed of 6 mm/min once more by identical hot-zone and atmosphere to carry out last sintering.Expect as us, find that described coating glass does not contain seed.This test specimen is placed 24 hours to discharge helium in being set in 1000 ℃ the maintenance heating furnace of argon purge.According to mode similar to Example 1 described test specimen is drawn into 125 micron fiber then, finds that it does not contain hole (as expection).Record the long optical fiber of 2.4Km by time cutting method and can't transmit light (illustrating that decay is greater than 100dB/Km); This is among expecting, because do not have refractive index difference between core and clad.

Those skilled in the art can clearly find out, can carry out various improvement and change under the prerequisite that does not deviate from spirit and scope of the invention.Therefore the present invention includes all these improvement and change, as long as it is included in the scope of appended claims and content of equal value thereof.

Claims

1. the optical fiber of a micro-structural, it comprises:

Have the core zone of first refractive index and clad zone with second refractive index, described second refractive index is less than first refractive index in core zone, feasible light by described Optical Fiber Transmission is generally retained in described in-core, comprise the zone that at least one is made up of the hole of a large amount of aperiodicity location in the described clad, the maximum gauge in the described hole greater than 95% is equal to or less than 1550 nanometers, and the decay of described optical fiber under at least a wavelength between the 600-1550 nanometer is less than 500dB/km.

2. the optical fiber of micro-structural as claimed in claim 1 is characterized in that, the maximum gauge greater than 95% described hole in the described optical fiber is equal to or less than 775 nanometers.

3. the optical fiber of micro-structural as claimed in claim 1 is characterized in that, described optical fiber in the decay of 1550 nanometers less than 200dB/km.

4. the optical fiber of micro-structural as claimed in claim 3 is characterized in that, the regional hole area percent in the whole zone that contains the hole is approximately greater than 0.5% and approximately less than 20% in the clad of described optical fiber.

5. the optical fiber of micro-structural as claimed in claim 1 is characterized in that, the zone in the described hole that comprises non-periodic distribution not with the core direct neighbor.

6. the optical fiber of micro-structural as claimed in claim 3 is characterized in that, with described core at a distance of 10 microns regional hole area percent with at least a portion of interior described optical fibre packages coating approximately greater than 1.0%.

7. the optical fiber of micro-structural as claimed in claim 1 is characterized in that, described core comprises germanium.

8. the optical fiber of micro-structural as claimed in claim 3 is characterized in that, described core comprises germanium.

9. the optical fiber of micro-structural as claimed in claim 7 is characterized in that, described optical fiber is when being 10 millimeters mandrel bending around diameter, and the decay under 1550 nanometers increases encloses less than 20dB/.

10. the optical fiber of micro-structural as claimed in claim 1 is characterized in that, the maximum gauge in described each hole is less than 375 nanometers.

11. the optical fiber of a micro-structural, it comprises:

Have the core zone of first refractive index and clad zone with second refractive index, described second refractive index is lower than first refractive index in core zone, make the light that in described optical fiber, transmits remain on substantially in the core zone, comprise the zone of containing the hole in the described clad, the described zone of containing the hole is made up of the hole of a large amount of aperiodicity location, the maximum gauge at least 95% hole is equal to or less than 1550 nanometers in the described zone that contains the hole, and total optical fiber hole area percent of described optical fiber is greater than 0.01%.

12. the optical fiber of micro-structural as claimed in claim 11 is characterized in that, total optical fiber hole area percent of described optical fiber is less than 10%.

13. the optical fiber of micro-structural as claimed in claim 11 is characterized in that, the average fibre diameter of described optical fiber is less than 1550 nanometers, and the standard deviation in described hole is less than 1 micron.

14. the optical fiber of micro-structural as claimed in claim 11 is characterized in that, described optical fiber is when being 10 millimeters mandrel bending around diameter, and its decay under 1550 nanometers increases encloses less than 20dB/.

15. the optical fiber of micro-structural as claimed in claim 12 is characterized in that, described zone and the described core that contains the hole separates.

16. the optical fiber of micro-structural as claimed in claim 11 is characterized in that, the described zone that contains the hole comprises at least 25 holes, and the mean diameter in hole is less than 2000 nanometers in the described zone that contains the hole.

17. the optical fiber of micro-structural as claimed in claim 11 is characterized in that, the described zone that contains the hole comprises at least 25 holes, and the mean diameter in hole is less than 775 nanometers in the described zone that contains the hole.

18. the optical fiber of a micro-structural, it comprises:

Have the core zone of first refractive index and clad zone with second refractive index, described second refractive index is lower than first refractive index in core zone, make the light that in described optical fiber, transmits remain on substantially in the core zone, comprise a zone in the described clad, described zone surrounds described core zone, form less than the hole of 750 nanometers approximately less than 2000 nanometers, standard deviation approximately by mean diameter, describedly comprise the zone in hole and the core zone of described optical fiber separates.

19. the optical fiber of micro-structural as claimed in claim 18 is characterized in that, the described zone that comprises the hole comprises about 25-200 hole.

20. the optical fiber of micro-structural as claimed in claim 18 is characterized in that, the mean diameter in hole is less than 775 nanometers in the described zone that comprises the hole.

21. the optical fiber of micro-structural as claimed in claim 18 is characterized in that, described optical fiber is when being 10 millimeters mandrel bending around diameter, and its decay under 1550 nanometers increases encloses less than 20dB/.

22. the optical fiber of micro-structural as claimed in claim 18 is characterized in that, described optical fiber is when being 10 millimeters mandrel bending around diameter, and its decay under 1550 nanometers increases encloses less than 15dB/.

23. a method of making optical fiber, this method comprises:

Form the predispersed fiber formed body that comprises cigarette ash by the CVD operation;

Make that under certain gas atmosphere and condition the cigarette ash in the described soot-laden preform is fixed, described condition is enough in described consolidation step the part of described gas atmosphere is captured in the described preform, thereby be formed on the fixed preform that has the hole in the described preform

In manufacture process, use described preform to make optical fiber, described optical fiber comprises core zone with first refractive index and the clad zone with second refractive index, described second refractive index is less than first refractive index in core zone, comprise a zone in the described clad, comprise in this zone around the hole of the aperiodicity location of described core, in the described optical fiber from cross-sectional view, total optical fiber hole area percent is greater than 0.05%.

24. method as claimed in claim 23, it is characterized in that, described consolidation step comprises: in stove, make under 1500 ℃ the temperature that the described performing member that comprises cigarette ash is fixed being higher than, heat described performing member with at least one first rate temperature change greater than 10 ℃, described gas atmosphere comprises and is selected from following at least a gas: nitrogen, argon gas, CO ₂, oxygen, chlorine, CF ₄, CO, SO ₂With their potpourri, in manufacture process, use the step of described preform to comprise with described preform drawing optical fiber, make the described hole that in consolidation step, forms be retained in the described optical fiber.

25. method as claimed in claim 23, it is characterized in that, in described consolidation step, the described preform that comprises cigarette ash comprises the core zone at least one no hole, deposited other cigarette ash by described CVD operation thereon, described consolidation step obtains having the described preform in hole in the described clad zone of described fixed preform.

26. method as claimed in claim 23 is characterized in that, the maximum cross section diameter in each described hole is less than 1550 nanometers.

27. method as claimed in claim 24 is characterized in that, described cigarette ash preform comprises tubular preform, and described fixed preform comprises tubular preform.

28. method as claimed in claim 23, it is characterized in that, the step that described formation comprises the predispersed fiber formed body of cigarette ash comprises: with the outside of smoke deposition at the glass plug, described consolidation step is carried out after described formation comprises the step of predispersed fiber formed body of cigarette ash by CVD.

29. method as claimed in claim 23, it is characterized in that, the described step that described preform is used for manufacture process also comprises: described fixed preform is drawn into optical fiber, the described hole that forms in described consolidation step remains in described drawing step and is out of shape, after described drawing step, described hole is retained in the described optical fiber.

30. method as claimed in claim 23 is characterized in that, described gas atmosphere comprises and is selected from following at least a gas: argon gas, nitrogen, carbon monoxide, carbon dioxide, oxygen, CF ₄, C ₂F ₆, Kr and their potpourri.

31. a method of making optical fiber, this method comprises:

In a kind of gas atmosphere, fixed described cigarette ash preform under certain conditions, described gas comprises and is selected from following at least a gas: nitrogen, argon gas, CO ₂, oxygen, chlorine, CF ₄, CO, SO ₂With their potpourri, described condition can be in described consolidation step be captured in the part of described gas atmosphere in the described preform effectively, thereby forms the hole in described fixed preform,

In manufacture process, use described fixed preform to form optical fiber, described optical fiber comprises core zone with first refractive index and the clad zone with second refractive index, described second refractive index is lower than first refractive index of described core, feasible light by described Optical Fiber Transmission all remains within the core basically, and described hole is located substantially in the clad of described optical fiber at least.

32. method as claimed in claim 31, it is characterized in that, described consolidation step comprises: at first described preform is applied the temperature that is approximately higher than 1500 ℃, and with the charging in consolidation furnace of certain feed rate, described temperature and feed rate are enough to make at least a portion of described preform to heat up with the speed greater than 12 ℃/minute approximately.

33. method as claimed in claim 31, it is characterized in that, described consolidation step comprises: at first described preform is applied certain temperature, and with certain feed rate to the consolidation furnace charging, described temperature and feed rate are enough to make described preform to heat up with the speed greater than 14 ℃/minute approximately.

34. method as claimed in claim 33 is characterized in that, described consolidation step comprises described performing member is placed in the stove that remains on the temperature that is equal to or higher than 1390 ℃.

35. method as claimed in claim 32, it is characterized in that, described consolidation step also comprises: after the step of the described first time through being subject to processing, described preform is applied uniform temperature and with the charging in consolidation furnace of certain charging rate, and described temperature and charging rate are enough to make the heating rate of described preform at least than low 2 ℃/minute of the heating rate that stands for the first time in the treatment step.

36. method as claimed in claim 32, it is characterized in that, described consolidation step also is included in and stands after the treatment step the described first time, described preform is applied uniform temperature and with the charging in consolidation furnace of certain charging rate, and described temperature and charging rate are enough to make the heating rate of described preform at least than low 2 ℃/minute of the heating rate that stands for the first time in the treatment step.

37. method as claimed in claim 35 is characterized in that, described atmosphere comprises and is selected from following at least a gas more than the 85 volume %: nitrogen, argon gas and their combination, remaining gas is made up of helium at least substantially in the described atmosphere.

38. method as claimed in claim 31 is characterized in that, described atmosphere comprises greater than the nitrogen of 65 volume % and/or argon gas.

39. method as claimed in claim 31, it is characterized in that, described method also comprises following (1) or (2): (1) by with described smoke deposition on Ge-doped core billot, form the described preform that comprises cigarette ash, perhaps (2) are inserted through the clad zone that comprises the hole that described consolidation step forms with Ge-doped core billot.

40. method as claimed in claim 31 is characterized in that, the zone in the described hole that comprises non-periodic distribution not with described core direct neighbor.

41. one kind is the optical fiber of the micro-structural of multimode form under 1550 nanometers, described optical fiber comprises:

Have the core zone of first refractive index and clad zone with second refractive index, described second refractive index is less than first refractive index in core zone, feasible light by described Optical Fiber Transmission is generally retained in described in-core, comprise the zone that at least one is made up of the hole of a large amount of aperiodicity location in the described clad, described optical fiber is multimode under 1550 nanometers, when described optical fiber is 5 millimeters mandrel when reeling a circle around radius, the decay of described optical fiber under 1550 nanometers increases encloses less than 1dB/.