CN113912279B - Axial deposition doping device and preparation method of powder rod - Google Patents
Axial deposition doping device and preparation method of powder rod Download PDFInfo
- Publication number
- CN113912279B CN113912279B CN202010664962.2A CN202010664962A CN113912279B CN 113912279 B CN113912279 B CN 113912279B CN 202010664962 A CN202010664962 A CN 202010664962A CN 113912279 B CN113912279 B CN 113912279B
- Authority
- CN
- China
- Prior art keywords
- alkali metal
- deposition
- conduit
- guide pipe
- doping
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/01406—Deposition reactors therefor
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2207/00—Glass deposition burners
- C03B2207/36—Fuel or oxidant details, e.g. flow rate, flow rate ratio, fuel additives
Abstract
The invention provides an axial deposition doping device and a preparation method of a powder rod. The device comprises a deposition cavity, a suspender hung at the center of the top of the deposition cavity, a target rod arranged at the free end of the suspender deep into the deposition cavity, and a deposition doping mechanism arranged in the deposition cavity, wherein the deposition doping mechanism comprises a first blast lamp integrated with a first alkali metal atomization device, the first alkali metal atomization device is communicated with the first blast lamp, and the first blast lamp is arranged towards the target rod; or the deposition doping mechanism comprises a second blowtorch and a second alkali metal atomization device which are arranged in opposite directions, and a first internal cavity which is arranged on the peripheral side of the second blowtorch and the second alkali metal atomization device, and an opening of the first internal cavity faces the target rod. The axial deposition doping device is used for doping alkali metal while performing vapor deposition outside the tube, has high doping uniformity, increases and controls the doping amount, and can reduce the attenuation of the optical fiber.
Description
Technical Field
The invention relates to the technical field of optical fibers, in particular to an axial deposition doping device and a preparation method of a powder rod.
Background
With the development of optical communication technology, especially in the future 400G and above transmission systems, the reduction of optical fiber loss will have higher and higher requirements on optical fiber loss with the continuous development of long-distance optical fiber transmission, especially the rapid development of internet technology and 5G technologies. The optical fiber loss is reduced, so that relay stations can be reduced in long-distance low-attenuation high-speed transmission, the cost is reduced, and the transmission quality is improved. As an optical fiber having a low rayleigh scattering loss and a low transmission loss, a silica optical fiber having a core rod containing an alkali metal element or an alkaline earth metal element is known. Such an optical fiber is manufactured by drawing an optical fiber preform whose core layer contains an alkali metal element or an alkaline earth metal element. When the core layer of the optical fiber preform contains an alkali metal element or an alkaline earth metal element, the viscosity of the core layer can be reduced and the network structure of the silica glass can be made uniform in the drawing process of the optical fiber preform. Therefore, rayleigh scattering loss caused by structural unevenness can be reduced. At present, an alkali metal element or the like is generally added to silica glass by a diffusion method.
In the existing low-loss optical fiber, the core region adopts an alkali metal diffusion doping technology, so that the viscosity matching of the core layer and the cladding is realized, but the viscosity mismatching caused by interface diffusion still exists by adopting the method, so that the attenuation stability of the optical fiber is influenced, and the ideal state cannot be achieved. In addition, the existing low-loss optical fiber alkali metal doping process mostly adopts a method of heating outside a tube and doping inside the tube, and the method has the advantages of slow production speed, low efficiency after industrialization and high cost. It is well known that the outside deposition method is more advantageous than the inside deposition method in producing a single mold, and has high efficiency and low cost. In the prior art, a gas-phase axial deposition method is adopted to prepare a preform, and a mode of heating alkali metal salt solution to prepare steam is adopted, doping is carried out simultaneously during deposition, but along with the increase of deposition time, the alkali metal salt solution volatilizes, the steam concentration is always reduced, so that the concentration of alkali metal doped in a core rod is not uniform, the attenuation also fluctuates, and the method is not suitable for large-scale production of the preform of a low-loss optical fiber. The preform is prepared by adopting a vapor axial deposition method, the alkali metal salt solution passes through an ultrasonic atomizer and is sprayed out by an atomizing nozzle for doping, but the atomizing stability, the droplet size and the uniformity of the atomizer are difficult to control, and the particles sprayed by atomization are influenced by air draft in a cavity, so that the actual deposition doping amount is lower.
Disclosure of Invention
In view of the above, there is a need for an improved axial deposition doping apparatus and method of making a powder rod.
The technical scheme provided by the invention is as follows: an axial deposition doping device comprises a deposition cavity, a hanging rod hung at the center of the top of the deposition cavity, a target rod arranged at the free end of the hanging rod extending into the deposition cavity, and a deposition doping mechanism arranged in the deposition cavity, wherein the deposition doping mechanism comprises a first torch integrated with a first alkali metal atomization device, the first alkali metal atomization device is communicated with the first torch, and the first torch is arranged towards the target rod; or the deposition doping mechanism comprises a second blowtorch and a second alkali metal atomization device which are arranged in opposite directions, and a first internal cavity which is arranged on the peripheral side of the second blowtorch and the second alkali metal atomization device, and an opening of the first internal cavity faces the target rod.
Further, the deposition doping device further comprises a second internal cavity which is enclosed on the periphery of the first torch, and the first torch is stably deposited and doped towards the target rod through an opening of the second internal cavity.
Furthermore, a boron tribromide device is arranged at the joint of a raw material pipeline of the axial deposition doping device and the first blast burner or the second blast burner, and boron tribromide is loaded into the raw material pipeline in a bubbling manner.
Further, first alkali metal atomizing device or second alkali metal atomizing device includes ultrasonic nebulizer and atomizer, ultrasonic nebulizer is equipped with the carrier gas pipeline to let in the carrier gas, the carrier gas can carry the atomized alkali metal solution of ultrasonic nebulizer follows atomizer blowout.
Furthermore, the second blowtorch is provided with a first bypass conduit for introducing hydrogen, a second bypass conduit for introducing oxygen, and a central conduit; and introducing silicon tetrachloride and germanium tetrachloride or introducing silicon tetrachloride, germanium tetrachloride and boron tribromide into the central conduit.
Furthermore, the first blowtorch is provided with nine concentric conduits which are sequentially and radially overlapped and comprise a core conduit arranged at the most center, a second conduit sleeved on the core conduit, a third conduit sleeved on the second conduit, a fourth conduit sleeved on the third conduit, a fifth conduit sleeved on the fourth conduit, a sixth conduit sleeved on the fifth conduit, a seventh conduit sleeved on the sixth conduit, an eighth conduit sleeved on the seventh conduit and a ninth conduit sleeved on the eighth conduit; and introducing silicon tetrachloride and germanium tetrachloride into the core conduit, or introducing silicon tetrachloride, germanium tetrachloride and boron tribromide into the core conduit, and introducing oxygen, argon, hydrogen, argon, oxygen, argon, atomized alkali metal solution and hydrogen respectively between two radially adjacent conduits along the concentric conduit.
Furthermore, the fifth guide pipe protrudes from the rest guide pipes in the extending direction of the fifth guide pipe.
Further, the outlet ends of the core duct, the second duct, the third duct and the fourth duct are flush, the fifth duct protrudes 20mm in its extension direction with respect to the outlet end of the core duct, the outlet ends of the sixth duct, the seventh duct and the eighth duct are flush and are retracted 10mm in their extension direction with respect to the fifth duct, and the ninth duct is retracted 5mm in its extension direction with respect to the eighth duct.
Furthermore, the axial deposition doping device further comprises a plurality of third torches arranged side by side with the first torches or the second torches, and the third torches are arranged towards the target rod.
Furthermore, a boron tribromide device is arranged at the joint of a raw material pipeline of the axial deposition doping device and the third blast lamp, and boron tribromide is loaded into the raw material pipeline in a bubbling manner.
The invention also provides a preparation method of the powder rod, which applies the axial deposition doping device to prepare the powder rod and comprises the following steps:
atomizing an alkali metal solution by using a first alkali metal atomizing device, and spraying oxygen with the purity of more than 99.99 percent as a carrier gas from an atomizing nozzle of the first alkali metal atomizing device, wherein the inlet temperature of the carrier gas is set to be 50-60 ℃, and the temperature of the atomizing nozzle is set to be 80-100 ℃;
spraying and depositing silicon dioxide, germanium dioxide and oxides of metal salts generated after the atomized alkali metal solution sprayed by the first blast lamp reacts with the raw materials on the target rod;
the suspension rod rotates and rises, and the powder rod is formed through axial deposition.
The invention also provides a preparation method of the powder rod, which applies the axial deposition doping device to prepare the powder rod and comprises the following steps:
atomizing an alkali metal solution by adopting a second alkali metal atomizing device, and spraying oxygen with the purity of more than 99.99 percent as a carrier gas from an atomizing spray head of the second alkali metal atomizing device, wherein the inlet temperature of the carrier gas is set to be 50-60 ℃, and the temperature of the atomizing spray head is set to be 80-100 ℃;
the sprayed atomized alkali metal solution and the raw material sprayed from the second burner react to generate silicon dioxide, germanium dioxide and metal salt oxide, and the silicon dioxide, the germanium dioxide and the metal salt oxide are sprayed out through the opening of the first internal cavity and deposited on the target rod;
the suspension rod rotates and rises, and the powder rod is formed through axial deposition.
Further, the alkali metal in the alkali metal solution comprises one of sodium, potassium, rubidium and cesium; the raw material comprises a combination of silicide and germanium tetrachloride or a combination of silicide and carbon tetrafluoride or a combination of silicide and germanium tetrachloride and carbon tetrafluoride.
Further, the silicide includes germanium tetroxide or octamethylcyclotetrasiloxane.
Further, the raw material also comprises boron tribromide, and the boron tribromide is loaded into a raw material pipe in a bubbling mode and is introduced into the first blast lamp or the second blast lamp.
Compared with the prior art, the axial deposition doping device provided by the invention is used for doping alkali metal while performing vapor deposition outside the tube, the uniformity of doping can be improved while performing deposition and doping, the doping amount is controllable, and the doping content of the core layer or the cladding layer can be increased relative to the doping after deposition, so that the compressive stress of the core layer is increased, and the purpose of further reducing the attenuation of the optical fiber is achieved; and the axial deposition doping device has high deposition and doping efficiency, stable product quality and simple and convenient operation.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Fig. 1 is a schematic structural diagram of an axial deposition doping apparatus according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a first torch according to an embodiment of the invention.
Fig. 3 is a schematic structural view of an axial deposition doping apparatus using the first torch shown in fig. 2.
Fig. 4 is a graph comparing deposition rates of the first torch of the present invention and the conventional quadruple tube torch.
FIG. 5 is a flow chart illustrating the preparation of a powder stick according to one embodiment of the present invention.
FIG. 6 is a flow chart illustrating the preparation of a powder stick according to another embodiment of the present invention.
Fig. 7 is a schematic diagram of a sintering furnace temperature curve according to an embodiment of the present invention.
Description of the main element symbols:
Core catheter 21a
Ninth guide duct 21i
Second internal cavity 08
Deposition flame 24
Air draft air supply system 7
First internal cavity 8
Gas-carrying pipeline 9
Atomizing nozzle 11
Blowing line 13
Boron tribromide apparatus 14
The following detailed description further illustrates embodiments of the invention in conjunction with the above-described figures.
Detailed Description
So that the manner in which the above recited objects, features and advantages of embodiments of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the appended drawings. In addition, the features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the invention, and the described embodiments are merely some, but not all embodiments of the invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the present invention belong. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the invention.
The invention provides an axial deposition doping device, which comprises a deposition cavity 3, a suspender 6 suspended at the center of the top of the deposition cavity 3, a target rod 5 arranged at the free end of the suspender 6 extending into the deposition cavity 3, and a deposition doping mechanism arranged in the deposition cavity 3, wherein the deposition doping mechanism comprises a first torch 01 integrated with a first alkali metal atomizing device, the first alkali metal atomizing device is communicated with the first torch 01, and the first torch 01 is arranged towards the target rod 5; or the deposition doping mechanism comprises a second blast lamp 1 and a second alkali metal atomization device which are arranged in opposite directions, and a first internal cavity 8 surrounding the second blast lamp 1 and the second alkali metal atomization device, wherein the opening of the first internal cavity 8 faces the target rod 5. The axial deposition doping device is used for doping alkali metal while performing vapor deposition outside the tube, the uniformity of doping can be improved by performing deposition and doping simultaneously, the doping amount is controllable, and the doping content of the core layer or the cladding layer can be increased relative to the doping after deposition, so that the compressive stress of the core layer is increased, and the purpose of further reducing the attenuation of the optical fiber is achieved; and the axial deposition doping device has high deposition and doping efficiency, stable product quality and simple and convenient operation.
Referring to fig. 1, fig. 1 shows a specific structure of an axial deposition doping apparatus according to an embodiment of the present invention. As shown in the figure, axial deposit doping device main part is vertical setting, roughly includes deposition cavity 3, jib 6, target bar 5 and first inside cavity 8, and wherein, convulsions air supply system 7 is installed on deposition cavity 3's lateral wall upper portion, and first inside cavity 8 sets up in the deposition cavity 3, its opening sets up towards target bar 5, and first inside cavity 8 embeds there are second blowtorch 1 and second alkali metal atomizing device to carry out powder deposition and doping on target bar 5 and obtain the powder stick.
A deposition chamber 3, the lower portion of which is substantially spherical as shown in the figure, providing a raw material reaction site; the upper part is generally cylindrical, hollow, and is used to mount the boom 6.
A suspension rod 6, which is vertically arranged, and the upper end of the suspension rod extends to the outside so as to be connected with a lifting rotating mechanism (not shown) to drive the suspension rod 6 to rotate in the circumferential direction and pull the suspension rod to move upwards vertically, so that the powder rod with the preset size is obtained by continuous deposition; the lower end of the boom 6, which is also referred to herein as the free end for loading the target rod 5, extends deep inside the deposition chamber 3.
And a target bar 5 for a base bar to which the reactant powder is deposited.
An induced draft air supply system 7 is typically used to create a stable cooling gas flow field within the deposition chamber 3.
In this embodiment, deposition and alkali metal doping are performed simultaneously by using a mode in which the second torch 1 (conventional torch) and the second alkali metal atomizing device are combined with the first inner cavity 8, wherein the first inner cavity 8 is surrounded and blocked by the second torch 1 and the second alkali metal atomizing device for stabilizing torch deposition flame (the flow rate from the center of the torch to the outer side is high in the middle and low in the side, so that the flow rate of cooling gas periodically fluctuates along the axial direction of the powder rod, resulting in fluctuation of the outer diameter of a preform rod finally deposited, resulting in deterioration of the stability of the cutoff wavelength and the diameter of a mold field), avoiding influence of ventilation on deposition efficiency in the deposition cavity 3 (the flow direction of cooling gas cannot be effectively controlled, the deposition flame has a small wrapping area on the powder rod, a large amount of powder cannot reach deposition and is directly pumped away along with the airflow, resulting in low collection efficiency), and making alkali metal diffuse and attach to the powder rod 4 more easily. In the embodiment, the first inner cavity 8 effectively controls the deposition flame of the blast lamp, so that the flow rate difference between the center and the side is reduced, and the flow rate of the deposition flame of the blast lamp is stabilized; and a large amount of powder is gathered and directionally deposited on the target rod 5, so that the interference of cooling gas on the powder to be deposited is reduced, and the deposition efficiency is obviously improved. Taking the first internal chamber 8 in fig. 1 as an example, it is composed of a cylindrical quartz chamber, and the size of the internal chamber is related to the size of the deposition burner and the size of the powder rod, and the corresponding relationship is shown in the following table. As can be seen from the table, the radius of the first internal cavity 8 is small, the alkali metal doping concentration is low, and in addition, the radius of the first internal cavity 8 is too large, so that the purpose of stabilizing the deposition flame cannot be achieved, and the cost is high; the depth of the first internal cavity 8 is not too large or too small, which can affect the contact area between the deposition flame and the target rod/powder rod and cause the alkali metal doping concentration to be lower; the size of the first internal cavity 8 is preferably set in the present invention at 150mm r200mm.
| Internal cavity size | Average concentration of alkali metal/PPM in core layer |
| Without |
10 |
| 100mm* |
12 |
| 150mm*R200mm | 25 |
| 200mm*R200mm | 25 |
| 300mm* |
15 |
In this embodiment, a suspension rod 6 is arranged in the deposition cavity 3, the second blowtorch 1 is arranged on one side of the suspension rod 6, the other side of the suspension rod is connected with the air suction opening of the air suction and supply system 7, the alkali metal atomizer is additionally arranged at the position corresponding to the nozzle of the second blowtorch 1 or the deposition formation position of the powder rod 4, and the first inner cavity 8 is additionally arranged at the core layer powder forming position.
A second torch 1 for carrying the raw materials into the apparatus forming a deposition flame, reacting to form silicon dioxide to be deposited on the target rod 5. In a specific embodiment, the second torch 1 is provided with a central conduit, a first bypass conduit and a second bypass conduit, wherein the central conduit is fed with silicon tetrachloride and germanium tetrachloride, or with silicon tetrachloride, germanium tetrachloride and boron tribromide; the first bypass conduit is used for introducing hydrogen; the second bypass conduit is used for introducing oxygen.
The second alkali metal atomization device is used for atomizing and spraying alkali metal solution and comprises an ultrasonic atomizer 10 and an atomization nozzle 11, wherein the ultrasonic atomizer 10 is provided with a carrier gas pipeline 9 so as to introduce carrier gas to carry the alkali metal solution atomized by the ultrasonic atomizer 10 to be sprayed out from the atomization nozzle 11. In the present embodiment, the alkali metal solution is atomized into small droplets by the ultrasonic atomizer 10 and sprayed out in the form of mist, and in the specific embodiment, the second alkali metal atomizer is provided separately from the second torch 1, and the former atomizer 11 is provided opposite to the latter nozzle, that is, the outlet of the atomizer is provided toward the outlet of the nozzle, more specifically, toward the front of the nozzle. As can be seen from fig. 1, the atomizer 11 is disposed toward the front of the nozzle of the second torch 1, and atomized alkali metal droplets are mixed into the deposition flame gas flow of the second torch 1 and then sprayed toward the target rod 5 through the opening of the first internal cavity 8 for deposition and doping.
According to the design requirements of the refractive index and the rod diameter of different layers, a third torch 2 is arranged in the embodiment, is arranged on the same side of the second torch 1, is arranged outside the first inner cavity 8 and faces the target rod 5. In other embodiments, the third torch 2 may not be provided, or two or more third torches 2 may be provided, and the specific structure of the third torch 2 refers to the second torch 1 or a common torch structure, such as a four-concentric tube type.
In this embodiment, a boron tribromide apparatus 14 is disposed at the connection between the raw material pipe 15 of the axial deposition doping apparatus and the second and third torches 1 and 2, and boron tribromide is carried into the raw material pipe 15 by bubbling. The boron tribromide is mainly doped for adjusting the viscosity of the core layer so as to facilitate the operation of a subsequent wire drawing process. In other embodiments, the boron tribromide apparatus 14 may not be provided, or may be separately configured in a torch, or, one boron tribromide apparatus 14 may be connected to different torches as shown in fig. 1, and may be determined according to actual production or design requirements.
Referring to fig. 3, the difference from the axial deposition doping apparatus shown in fig. 1 is that a first torch 01 integrated with a first alkali metal atomizer is used instead of the combination of the second torch 1 and the alkali metal atomizer, the first torch 01 is disposed in a second internal cavity 08, in other words, the second internal cavity 08 surrounds the first torch 01, and deposition and alkali metal doping can be performed simultaneously, and the first torch 01 and the integrated first alkali metal atomizer are disposed toward the target rod 5 through an opening of the second internal cavity 08. The structure of the first alkali metal atomizer is the same as that of the second alkali metal atomizer, and the first alkali metal atomizer also comprises an ultrasonic atomizer 10 and an atomizer 11, wherein the atomizer 11 is communicated with a conduit of the first torch 01, so that the deposition raw material and the doped alkali metal are sprayed out from the same torch, and the doping amount and the doping uniformity are superior to those of the mode in fig. 1 and far superior to the case of external diffusion doping. In other embodiments, the second internal cavity 08 shown in fig. 3 may not be provided (it is understood that the second internal cavity is more effective), and the deposition and the doping with the alkali metal may be performed simultaneously. The second internal cavity 08 has substantially the same function as the first internal cavity 8, and the relationship between the size and the actual technical effect is similar, so that the optimal scheme can be adjusted by reference to experiments. In other embodiments, the third torch 2 and/or the boron tribromide apparatus 14 may not be provided, or two or more third torches 2 may be provided, and so on, which are not described herein again.
Referring to fig. 2 again, the first torch 01 has nine concentric conduits sequentially nested radially, including a core conduit 21a disposed at the center, a second conduit 21b disposed on the core conduit 21a, a third conduit 21c disposed on the second conduit 21b, a fourth conduit 21d disposed on the third conduit 21c, a fifth conduit 21e disposed on the fourth conduit 21d, a sixth conduit 21f disposed on the fifth conduit 21e, a seventh conduit 21g disposed on the sixth conduit 21f, an eighth conduit 21h disposed on the seventh conduit 21g, and a ninth conduit 21i disposed on the eighth conduit 21 h; wherein the core conduit 21a is fed with silicon tetrachloride and germanium tetrachloride, or with silicon tetrachloride, germanium tetrachloride and boron tribromide. In this embodiment, oxygen, argon, hydrogen, argon, oxygen, argon, atomized alkali metal solution and hydrogen are respectively introduced between two adjacent conduits from outside to inside along the radial direction of the concentric conduit, and in other embodiments, the order of introducing oxygen, argon, hydrogen, argon, oxygen, argon, atomized alkali metal solution and hydrogen between two adjacent conduits along the radial direction of the concentric conduit may be changed at will, for example, the atomized alkali metal solution is exchanged with the adjacent argon, and the present invention is not limited to this embodiment. In a particular embodiment, said fifth duct 21e protrudes from the remaining ducts in the direction of extension thereof. The outlet ends of the core duct 21a, the second duct 21b, the third duct 21c and the fourth duct 21d are flush, the fifth duct 21e protrudes 20mm in its extending direction with respect to the outlet end of the core duct 21a, the outlet ends of the sixth duct 21f, the seventh duct 21g and the eighth duct 21h are flush and are retracted 10mm in its extending direction with respect to the fifth duct 21e, and the ninth duct 21i is retracted 5mm in its extending direction with respect to the eighth duct 21 h. As can also be seen, the ninth conduit 21i is sheathed with a nozzle 23 of the first torch, which nozzle 23 in its extension has an outlet end which is approximately flush with the widest region of the deposition flame 24. The dopant content in the powder rod 4 can be effectively improved through the reasonable design of the structure of the first torch 01. The improved blowtorch structure makes the blowtorch reaction center move forward along the spraying direction and get closer to the target rod, the stroke of deposited powder is shortened, the collection rate is further improved, and the doping amount of alkali metal is effectively improved. In other words, in the conventional burner structure, the reaction material reacts directly near the outlet of the core tube, and the collection rate of the deposited powder is low due to the influence of the draft. The design of the nine-fold tube blast lamp is different from that of the traditional four-fold tube blast lamp, wherein the fifth layer of the blast lamp protrudes out of other layers, so that the deposition rate is improved; as shown in fig. 4, the deposition rate of the core burner is about 2 times that of the conventional four-layer burner.
Referring to fig. 5, the method for preparing a powder rod using the axial deposition doping apparatus shown in fig. 3 includes the following steps.
Step S11, atomizing an alkali metal solution by using a first alkali metal atomizing device, and spraying oxygen with the purity of more than 99.99% as carrier gas from an atomizing nozzle of the first alkali metal atomizing device, wherein the inlet temperature of the carrier gas is set to be 50-60 ℃, and the temperature of the atomizing nozzle is set to be 80-100 ℃.
Step S12, spraying the atomized alkali metal solution sprayed by the first burner and the silicon dioxide, germanium dioxide and metal salt oxide generated after the reaction of the raw materials on the target rod;
and S13, rotating and lifting the suspender, and axially depositing to form a powder rod.
Referring to fig. 6, the method for preparing a powder rod using the axial deposition doping apparatus shown in fig. 1 includes the following steps.
Step S21, atomizing an alkali metal solution by using a second alkali metal atomizing device, and spraying oxygen with the purity of more than 99.99 percent as a carrier gas from an atomizing nozzle of the second alkali metal atomizing device, wherein the inlet temperature of the carrier gas is set to be 50-60 ℃, and the temperature of the atomizing nozzle is set to be 80-100 ℃;
step S22, spraying the sprayed atomized alkali metal solution and the raw material sprayed from the second burner to generate silicon dioxide, germanium dioxide and metal salt oxide, and depositing the silicon dioxide, the germanium dioxide and the metal salt oxide on the target rod through the opening of the first internal cavity;
and S23, rotating and lifting the suspender, and axially depositing to form a powder rod.
In specific embodiments, the alkali metal in the alkali metal solution depicted in fig. 5 or fig. 6 comprises one of sodium, potassium, rubidium, and cesium; the raw material comprises a combination of silicide and germanium tetrachloride or a combination of silicide and carbon tetrafluoride or a combination of silicide and germanium tetrachloride and carbon tetrafluoride. The silicide includes germanium tetraoxide or octamethylcyclotetrasiloxane. The raw material also comprises boron tribromide, and the boron tribromide is loaded into the raw material pipe in a bubbling mode and is introduced into the first blast lamp or the second blast lamp.
The preparation of the powder stick according to the invention will now be described with reference to specific examples.
Example 1
Preparation of 30% concentration KNO 3 Aqueous solution, the purified aqueous solution was charged into an ultrasonic atomizer 10 shown in fig. 1, and argon gas was introduced into the atomized solution through a carrier gas line 9 under pressure. Boron tribromide (BBr) is added at the joint of the raw material pipeline 15 and the second and third torches 1 and 2 3 ) Means 14 for bubbling BBr 3 Is carried into the feedstock tube, typically using high purity argon, helium or oxygen as a carrier gas, from a gas blowing line 13 into the boron tribromide (BBr) 3 ) A device 14; the inlet air temperature: 30 to 40 ℃; water bath temperature: 35 to 45 ℃; discharging temperature: 55-85 ℃. The raw material SiCl was introduced through the central tube of the second torch 1 4 、GeCl 4 、BBr 3 Respectively using the raw materials at a speed of 3.5g/min,introducing hydrogen and oxygen at flow rates of 200cc/min and 20cc/min respectively from other conduits, and burning to form deposition flame, KNO 3 The aqueous solution was sprayed from the atomizer 11 through the atomizer 11 with a carrier gas Ar of 50cc and injected into the flame 12. The atomizer 11 must be retained in the first internal cavity 8 to effectively increase the utilization rate; siCl as a material of a central duct of the third torch 2 4 、CF 4 、BBr 3 Respectively introducing at the flow rates of 20g/min,500cc/min and 20cc/min, respectively introducing hydrogen and oxygen from other guide pipes, attaching oxides to the target rod 5, simultaneously forming a cooling airflow flow field in the deposition cavity 3 by the air draft and supply system 7, and gradually forming the powder rod 4 by leading the suspender 6 at the speed of 15rpm and 40-60 mm/h. The outer cladding can be produced by OVD (outside vapor deposition) deposition processes, or by fusing using high purity quartz sleeves.
After deposition, the fiber is sintered and drawn into an optical fiber. And (4) dehydroxylating and vitrifying sintering the deposited powder rod 4 in a sintering furnace. As shown in fig. 7, the following stages are divided: in the first stage, the dehydroxylation temperature T1 is controlled to be 1050-1150 ℃; in the second stage, after the dehydroxylation is finished, the temperature is increased to the temperature of between 1300 and 1600 ℃ according to the heating rate of between 3 and 6 ℃/min, and He of between 10 and 30L/min is kept introduced; in the third stage, after the temperature is raised to the target temperature, the constant temperature time is 4-6 h, and the powder rod is further sintered into a transparent glass body; in the fourth stage, after sintering, the temperature is reduced to T3 1050-1300 ℃ according to the cooling rate of 3-6 ℃/min on the basis of the T2 temperature, the temperature is kept for 2-4 h, and N of 5-15L/min is introduced 2 . In other embodiments, the sintering profile may be different, depending on the design.
The optical fiber optical parameters prepared by the embodiment are tested by an optical time-domain reflectometer (OTDR) and other related instruments, namely the attenuation value of the ultra-low loss optical fiber at the wavelength of 1550nm is less than or equal to 0.158db/km, the cut-off wavelength of the cabled ultra-low loss optical fiber is less than or equal to 1490nm, and the mode field diameter at the wavelength of 1550nm is less than or equal to 12.5 mu m.
Example 2
Preparation of 30% KNO 3 An aqueous solution, charging the purified aqueous solution into an ultrasonic atomizer under pressureArgon gas was then used as a carrier gas through the conduit into the atomized solution. Boron tribromide (BBr) is added at the joint of the raw material pipeline 15 and the second and third torches 1 and 2 3 ) Means 14 for bubbling BBr 3 Loaded into the feedstock tube, typically using high purity argon, helium or oxygen as a carrier gas, from the gas blowing line 13 into the boron tribromide (BBr) 3 ) A device 14; the inlet air temperature: 30 to 40 ℃; water bath temperature: 35 to 45 ℃; discharging temperature: 55-85 ℃. Using a first torch 01 having nine concentric ducts 21a to 21i, siCl was introduced as shown in FIG. 2 4 、GeCl 4 、BBr 3 Respectively at 3.5g/min,200cc/min,20cc/min, introducing hydrogen gas into the passage between the second conduit 21b and the core conduit 21a, introducing atomized alkali metal droplets at 100cc/min into the passage between the third conduit 21c and the second conduit 21b, introducing Ar into the passage between the fourth conduit 21d and the third conduit 21c, and introducing O into the passage between the fifth conduit 21e and the fourth conduit 21d 2 Ar is introduced into a passage between the sixth guide duct 21f and the fifth guide duct 21e, and H is introduced into a passage between the seventh guide duct 21g and the sixth guide duct 21f 2 Ar is introduced into a passage between the eighth conduit 21h and the seventh conduit 21g, and O is introduced into a passage between the ninth conduit 21i and the eighth conduit 21h 2 The raw material and the atomized alkali metal solution are oxidized and attached to the target rod 5, meanwhile, the air draft and air supply system 7 forms a cooling airflow flow field in the deposition cavity 3, and the hanger rod 6 is guided up at a speed of 40-60 mm/h at a rotating speed of 15rpm to gradually form a powder rod. The outer cladding can be produced by OVD (outside vapor deposition) deposition processes, or by fusing using high purity quartz sleeves.
After deposition, the fiber is sintered and drawn into an optical fiber. And (4) dehydroxylating and vitrifying sintering the deposited powder rod in a sintering furnace. As shown in fig. 7, the following stages are divided: in the first stage, the dehydroxylation temperature T1 is controlled to be 1050-1150 ℃; in the second stage, after the dehydroxylation is finished, the temperature is increased to the temperature of between 1300 and 1600 ℃ according to the heating rate of between 3 and 6 ℃/min, and He of between 10 and 30L/min is kept introduced; in the third stage, after the temperature is raised to the target temperature, the constant temperature time is 4-6 h, and the powder rod is further sintered into a transparent glass body; the fourth stage, sintering is finishedThen the temperature is reduced to T3 1050-1300 ℃ according to the cooling rate of 3-6 ℃/min on the basis of the T2 temperature, the temperature is kept for 2-4 h, and N of 5-15L/min is introduced 2 . In other embodiments, the sintering profile may be different, depending on the design.
The optical parameters of the optical fiber manufactured by the embodiment are tested by OTDR and other related instruments, the attenuation value of the ultra-low loss optical fiber at the wavelength of 1550nm is less than or equal to 0.150db/km, the cut-off wavelength of the ultra-low loss optical fiber after cabling is less than or equal to 1450nm, and the mode field diameter at the wavelength of 1550nm is less than or equal to 12.5 mu m.
In conclusion, the axial deposition equipment is improved, the first blowlamp of the internal cavity and/or the integrated alkali metal atomization device is designed, the axial deposition and the alkali metal doping are simultaneously carried out, the alkali metal doping mode of the traditional outside-tube method thermal diffusion is replaced, the doping degree is effectively improved in the gas phase axial deposition process, the powder collection efficiency is improved, the production cost is reduced, and the large-scale production is facilitated. The design of the nine-fold tube blast burner of the first blast burner utilizes the atomized alkali metal solution, one layer of the alkali metal solution is introduced into the blast burner, and the alkali metal solution is mixed with the raw material and oxidized to be deposited on the target rod.
Although the embodiments of the present invention have been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the embodiments of the present invention.
Claims (12)
1. The axial deposition doping device comprises a deposition cavity, a suspender hung at the center of the top of the deposition cavity, a target rod arranged at the free end of the suspender deep into the deposition cavity, and a deposition doping mechanism arranged in the deposition cavity, and is characterized in that: the deposition doping mechanism comprises a first torch integrated with a first alkali metal atomization device, the first alkali metal atomization device is communicated with the first torch, and the first torch is arranged towards the target rod; or the deposition doping mechanism comprises a second blast lamp and a second alkali metal atomization device which are arranged oppositely, and a first internal cavity which is enclosed on the peripheral sides of the second blast lamp and the second alkali metal atomization device, and an opening of the first internal cavity faces the target rod;
the first blowtorch is provided with nine concentric guide pipes which are sequentially and radially overlapped and comprise a core guide pipe arranged at the most center, a second guide pipe sleeved on the core guide pipe, a third guide pipe sleeved on the second guide pipe, a fourth guide pipe sleeved on the third guide pipe, a fifth guide pipe sleeved on the fourth guide pipe, a sixth guide pipe sleeved on the fifth guide pipe, a seventh guide pipe sleeved on the sixth guide pipe, an eighth guide pipe sleeved on the seventh guide pipe and a ninth guide pipe sleeved on the eighth guide pipe; wherein silicon tetrachloride and germanium tetrachloride are introduced into the core conduit, or silicon tetrachloride, germanium tetrachloride and boron tribromide are introduced into the core conduit, and oxygen, argon, hydrogen, argon, oxygen, argon, atomized alkali metal solution and hydrogen are respectively introduced into the core conduit and the core conduit along the radial direction of the concentric conduit;
the outlet ends of the core, second, third and fourth conduits are flush, the fifth conduit projects 20mm in its direction of extension relative to the outlet end of the core conduit, the outlet ends of the sixth, seventh and eighth conduits are flush and are retracted 10mm in its direction of extension relative to the fifth conduit, and the ninth conduit is retracted 5mm in its direction of extension relative to the eighth conduit.
2. The axial deposition doping apparatus of claim 1, wherein: the deposition doping device further comprises a second inner cavity which is enclosed on the periphery of the first blast lamp, and the first blast lamp is stably deposited and doped towards the target rod through an opening of the second inner cavity.
3. The axial deposition doping apparatus of claim 1, wherein: and a boron tribromide device is arranged at the joint of the raw material pipeline of the axial deposition doping device and the first blast lamp or the second blast lamp, and boron tribromide is loaded into the raw material pipeline in a bubbling manner.
4. The axial deposition doping apparatus of claim 3, wherein: first alkali metal atomizing device or second alkali metal atomizing device includes ultrasonic nebulizer and atomizer, ultrasonic nebulizer is equipped with the carrier gas pipeline to let in the carrier gas, the carrier gas can carry ultrasonic nebulizer atomizing alkali metal solution is followed the atomizer blowout.
5. The axial deposition doping apparatus of claim 3, wherein: the second blowtorch is provided with a first bypass conduit for introducing hydrogen, a second bypass conduit for introducing oxygen, and a central conduit; and introducing silicon tetrachloride and germanium tetrachloride or introducing silicon tetrachloride, germanium tetrachloride and boron tribromide into the central conduit.
6. The axial deposition doping apparatus of claim 1, wherein: the fifth guide pipe protrudes from the remaining guide pipes in the extending direction thereof.
7. The axial deposition doping apparatus of claim 3, wherein: the axial deposition doping device further comprises a plurality of third torches arranged side by side with the first torches or the second torches, and the third torches are arranged towards the target rod.
8. The axial deposition doping apparatus of claim 7, wherein: and a boron tribromide device is arranged at the joint of a raw material pipeline of the axial deposition doping device and the third blast lamp, and boron tribromide is loaded into the raw material pipeline in a bubbling manner.
9. A method for preparing a powder rod by using the axial deposition doping apparatus according to any one of claims 1 to 8, comprising the steps of:
atomizing an alkali metal solution by using the first alkali metal atomizing device or the second alkali metal atomizing device, and spraying oxygen with the purity of more than 99.99 percent as a carrier gas from an atomizing nozzle of the first alkali metal atomizing device or the second alkali metal atomizing device, wherein the inlet temperature of the carrier gas is set to be 50-60 ℃, and the temperature of the atomizing nozzle is set to be 80-100 ℃;
spraying and depositing silicon dioxide, germanium dioxide and oxides of metal salts which are generated after the atomized alkali metal solution sprayed by the first blast burner reacts with the raw materials on the target rod; or the sprayed atomized alkali metal solution and the raw material sprayed from the second burner react to generate silicon dioxide, germanium dioxide and metal salt oxide which are sprayed out through the opening of the first internal cavity and deposited on the target rod;
the suspension rod rotates and rises, and the powder rod is formed through axial deposition.
10. The method of manufacturing a powder stick according to claim 9, wherein: the alkali metal in the alkali metal solution comprises one of sodium, potassium, rubidium and cesium; the raw material comprises a combination of silicide and germanium tetrachloride or a combination of silicide and carbon tetrafluoride or a combination of silicide and germanium tetrachloride and carbon tetrafluoride.
11. The method of manufacturing a powder stick according to claim 10, wherein: the silicide comprises octamethylcyclotetrasiloxane.
12. The method of manufacturing a powder stick according to claim 9, wherein: the raw material also comprises boron tribromide, and the boron tribromide is loaded into a raw material pipe in a bubbling mode and is introduced into the first blast lamp or the second blast lamp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010664962.2A CN113912279B (en) | 2020-07-10 | 2020-07-10 | Axial deposition doping device and preparation method of powder rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010664962.2A CN113912279B (en) | 2020-07-10 | 2020-07-10 | Axial deposition doping device and preparation method of powder rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113912279A CN113912279A (en) | 2022-01-11 |
| CN113912279B true CN113912279B (en) | 2023-03-31 |
Family
ID=79232384
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010664962.2A Active CN113912279B (en) | 2020-07-10 | 2020-07-10 | Axial deposition doping device and preparation method of powder rod |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113912279B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115784600A (en) * | 2022-09-30 | 2023-03-14 | 杭州金星通光纤科技有限公司 | Porous optical fiber preform deposition device and method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5650134A (en) * | 1979-09-26 | 1981-05-07 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of multicomponent type glass fiber base material |
| JPS58167442A (en) * | 1982-03-26 | 1983-10-03 | Nippon Telegr & Teleph Corp <Ntt> | Production of optical fiber parent material |
| CN107721149A (en) * | 2017-11-01 | 2018-02-23 | 江苏亨通光导新材料有限公司 | Axial vapor deposition method prepares ultra-low-loss fiber prefabricated rods and optical fiber |
| CN108585470A (en) * | 2018-05-10 | 2018-09-28 | 成都富通光通信技术有限公司 | A kind of VAD prepares the device and method of highly doped germanium plug |
| CN109206006A (en) * | 2017-06-29 | 2019-01-15 | 中天科技精密材料有限公司 | The manufacturing method of blowtorch and plug |
| CN110395900A (en) * | 2019-08-02 | 2019-11-01 | 长飞光纤光缆股份有限公司 | A kind of outer method of pipe prepares the precipitation equipment and method of low transmission loss optical fiber prefabricated rods |
| CN111320374A (en) * | 2018-12-15 | 2020-06-23 | 中天科技精密材料有限公司 | Optical fiber preform and method for manufacturing the same |
-
2020
- 2020-07-10 CN CN202010664962.2A patent/CN113912279B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5650134A (en) * | 1979-09-26 | 1981-05-07 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of multicomponent type glass fiber base material |
| JPS58167442A (en) * | 1982-03-26 | 1983-10-03 | Nippon Telegr & Teleph Corp <Ntt> | Production of optical fiber parent material |
| CN109206006A (en) * | 2017-06-29 | 2019-01-15 | 中天科技精密材料有限公司 | The manufacturing method of blowtorch and plug |
| CN107721149A (en) * | 2017-11-01 | 2018-02-23 | 江苏亨通光导新材料有限公司 | Axial vapor deposition method prepares ultra-low-loss fiber prefabricated rods and optical fiber |
| CN108585470A (en) * | 2018-05-10 | 2018-09-28 | 成都富通光通信技术有限公司 | A kind of VAD prepares the device and method of highly doped germanium plug |
| CN111320374A (en) * | 2018-12-15 | 2020-06-23 | 中天科技精密材料有限公司 | Optical fiber preform and method for manufacturing the same |
| CN110395900A (en) * | 2019-08-02 | 2019-11-01 | 长飞光纤光缆股份有限公司 | A kind of outer method of pipe prepares the precipitation equipment and method of low transmission loss optical fiber prefabricated rods |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113912279A (en) | 2022-01-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111694088B (en) | Single-mode optical fiber and preparation method thereof | |
| US4402720A (en) | Process for preparing glass preform for optical fiber | |
| US5110335A (en) | Method of glass soot deposition using ultrasonic nozzle | |
| US4367085A (en) | Method of fabricating multi-mode optical fiber preforms | |
| US20140161406A1 (en) | Method of manufacturing optical fiber preform and optical fiber | |
| CN103848565B (en) | The outer legal system of a kind of pipe makes the apparatus and method of preform | |
| US20120297837A1 (en) | Method for producing glass preform | |
| CN109553295B (en) | Large-size low-loss optical fiber preform and manufacturing method thereof | |
| CN108585470B (en) | Device and method for preparing high germanium-doped core rod by VAD (vapor axial deposition) | |
| GB2059944A (en) | Fabrication method of optical fiber preforms | |
| KR20070090747A (en) | Manufacture of depressed index optical fibers | |
| US8820121B2 (en) | Method of manufacturing optical fiber base material | |
| CN113912279B (en) | Axial deposition doping device and preparation method of powder rod | |
| EP2551248A2 (en) | Methods for manufacturing low water peak optical waveguide | |
| CN103922578A (en) | Method of fabricating an optical fiber preform and a burner therefor | |
| JP2005524597A (en) | Burner assembly for producing glass preform and corresponding production method | |
| GB2062615A (en) | Preparing glass preform for optical transmission | |
| CN114057388A (en) | Method for manufacturing optical fiber preform, and optical fiber | |
| US7003984B2 (en) | Hybrid manufacturing process for optical fibers | |
| JP4404767B2 (en) | Method and apparatus for producing preforms from synthetic quartz glass using plasma assisted deposition | |
| CN213266281U (en) | Core rod preparation device for large-size optical fiber perform | |
| CN113461322B (en) | Optical fiber and method for manufacturing optical fiber preform | |
| CN107056042B (en) | Blowtorch of optical fiber preform | |
| JP7195703B2 (en) | Burner for synthesizing porous body and method for producing porous body | |
| CN114349327A (en) | Low-cost processing technology of bending insensitive single-mode optical fiber |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |