CN113866867A - Dispersion compensation optical fiber and preparation method thereof - Google Patents

Dispersion compensation optical fiber and preparation method thereof Download PDF

Info

Publication number
CN113866867A
CN113866867A CN202111026517.4A CN202111026517A CN113866867A CN 113866867 A CN113866867 A CN 113866867A CN 202111026517 A CN202111026517 A CN 202111026517A CN 113866867 A CN113866867 A CN 113866867A
Authority
CN
China
Prior art keywords
layer
optical fiber
cladding
air holes
cladding layer
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.)
Pending
Application number
CN202111026517.4A
Other languages
Chinese (zh)
Inventor
李星
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fiberhome Fujikura Optic Technology Co ltd
Fiberhome Telecommunication Technologies Co Ltd
Original Assignee
Fiberhome Fujikura Optic Technology Co ltd
Fiberhome Telecommunication Technologies Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fiberhome Fujikura Optic Technology Co ltd, Fiberhome Telecommunication Technologies Co Ltd filed Critical Fiberhome Fujikura Optic Technology Co ltd
Priority to CN202111026517.4A priority Critical patent/CN113866867A/en
Publication of CN113866867A publication Critical patent/CN113866867A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/02214—Optical fibres with cladding with or without a coating tailored to obtain the desired dispersion, e.g. dispersion shifted, dispersion flattened
    • G02B6/02219—Characterised by the wavelength dispersion properties in the silica low loss window around 1550 nm, i.e. S, C, L and U bands from 1460-1675 nm
    • G02B6/02252—Negative dispersion fibres at 1550 nm
    • G02B6/02261—Dispersion compensating fibres, i.e. for compensating positive dispersion of other fibres
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
    • C03B37/01211—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments by inserting one or more rods or tubes into a tube
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/018—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
    • C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/02295—Microstructured optical fibre
    • G02B6/02314—Plurality of longitudinal structures extending along optical fibre axis, e.g. holes
    • G02B6/02342—Plurality of longitudinal structures extending along optical fibre axis, e.g. holes characterised by cladding features, i.e. light confining region
    • G02B6/02366—Single ring of structures, e.g. "air clad"
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
    • G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
    • G02B6/03661—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 4 layers only
    • G02B6/03666—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 4 layers only arranged - + - +
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
    • G02B6/03694—Multiple layers differing in properties other than the refractive index, e.g. attenuation, diffusion, stress properties

Abstract

The application relates to a dispersion compensation optical fiber and a preparation method thereof, wherein the dispersion compensation optical fiber comprises a core layer, a first sunken cladding layer, an inner cladding layer, a second sunken cladding layer and an outer cladding layer which are sequentially arranged from inside to outside along the radial direction; the refractive index of the second depressed cladding is smaller than that of the inner cladding and larger than that of the first depressed cladding; the core layer is doped with germanium, the core layer, the first depressed cladding layer, the inner cladding layer and the second depressed cladding layer are all doped with set elements, the doping amount of the set elements in the dispersion compensation optical fiber is gradually reduced from inside to outside along the radial direction, and the polarizability of the set elements is smaller than that of the germanium. By doping the low-polarizability elements, the viscosity matching of each layer can be effectively improved, and the core area stress is reduced, so that the attenuation loss of the optical fiber is reduced.

Description

Dispersion compensation optical fiber and preparation method thereof
Technical Field
The present disclosure relates to optical fiber technologies, and in particular, to a dispersion compensation optical fiber and a method for manufacturing the same.
Background
The optical fiber is prepared by melting and drawing an optical fiber preform at high temperature by a drawing machine and coating a high polymer material. There are more than ten international methods for producing silica optical fiber preform rods, and among them, the rod-making methods which are commonly used and can make high-quality optical fibers mainly include the following four methods: chemical Vapor Deposition (MCVD), extra-rod chemical vapor deposition (OVD), axial vapor deposition (VAD), plasma activated chemical vapor deposition (PCVD). The four processes have advantages and disadvantages, wherein the PCVD method can accurately control the refractive index profile of the prefabricated rod and manufacture the optical fiber with a complex structure.
Plasma activated chemical vapor deposition (PCVD) is a technique in which a reactive gas is activated by plasma to promote a chemical reaction in the surface space of a substrate tube and produce a solid film. The basic principle of the plasma chemical vapor deposition technology is that under the action of microwaves, source gas is ionized to form plasma, low-temperature plasma is used as an energy source, a proper amount of reaction gas is introduced, and the reaction gas is activated and the chemical vapor deposition is realized by utilizing plasma discharge. The PCVD method can meet the requirement of preparing the single-mode optical fiber with a complex optical fiber section by matching with different doping processes, and the dispersion compensation optical fiber is a typical example.
Dispersion Compensating Fiber (DCF) is a Fiber with large negative Dispersion. The existing G652 optical fiber system adopts WDM/EDFA technology, and the dispersion of the optical fiber system at the wavelength of 1.55 μm is not zero, but is positive 17ps/(nm · km), and has positive dispersion slope, so that a dispersion compensation optical fiber with negative dispersion needs to be additionally connected for dispersion compensation, so as to ensure that the total dispersion of the whole optical fiber line is approximately zero, and thus, high-speed, large-capacity and long-distance communication is realized. The Dispersion Compensation Module (DCM) is a DCF optical fiber reprocessing product, which is packaged in a 1U or smaller cabinet for use by DCF optical fiber coiling reinforcement, and fusing LC, SC, FC and other jumpers.
At present, the market of traditional communication link compensation is shrinking, DCM products taking DCF optical fibers as cores need to be upgraded, how to reduce the loss of dispersion compensation optical fibers and improve the bending resistance, so as to meet the demands of market miniaturization and low loss, and the problem to be solved is becoming urgent at present.
Disclosure of Invention
The embodiment of the application provides a dispersion compensation optical fiber and a preparation method thereof, and by doping low-polarizability elements, viscosity matching of each layer can be effectively improved, core region stress is reduced, and therefore attenuation loss of the optical fiber is reduced.
In a first aspect, a dispersion compensating fiber is provided, which comprises a core layer, a first depressed cladding layer, an inner cladding layer, a second depressed cladding layer and an outer cladding layer, which are sequentially arranged from inside to outside along a radial direction;
the refractive index of the second depressed cladding is smaller than that of the inner cladding and larger than that of the first depressed cladding;
the core layer is doped with germanium, the core layer, the first depressed cladding layer, the inner cladding layer and the second depressed cladding layer are all doped with set elements, the doping amount of the set elements in the dispersion compensation optical fiber is gradually reduced from inside to outside along the radial direction, and the polarizability of the set elements is smaller than that of the germanium.
In some embodiments, the set element comprises one or more of phosphorus P, aluminum Al, alkali metals, magnesium Mg, and beryllium Be.
In some embodiments, the doping amount of the set element is a curve;
the curve is a straight line; or, the curve is an arc line, and the absolute value of the slope of the curve gradually decreases from inside to outside along the radial direction; or the curve comprises a first straight line positioned on the core layer, a second straight line positioned on the first sunken cladding layer, a third straight line positioned on the inner cladding layer and a fourth straight line positioned on the second sunken cladding layer, wherein the first straight line, the second straight line, the third straight line and the fourth straight line are sequentially connected, and the absolute value of the slope of the first straight line is greater than the absolute value of the slope of the second straight line is greater than the absolute value of the slope of the third straight line is greater than the absolute value of the slope of the fourth straight line.
In some embodiments, the relative refractive index difference Δ of the core layer1% is 1.50% -2.50%, and the relative refractive index difference Delta of the first sunken cladding2% is-1.2% -0%, and the relative refractive index difference delta of the inner cladding3% of-0.2% -10%, relative refractive index difference delta of second depressed cladding4% is-0.5% -0%.
In some embodiments, the outer diameter of the core layer is 3-9 mm, the outer diameter of the first depressed cladding layer is 15-27 mm, the outer diameter of the inner cladding layer is 25-40 mm, and the outer diameter of the second depressed cladding layer is 36-52 mm.
In some embodiments, a first annular microporous layer is disposed on the first depressed cladding layer, the first annular microporous layer includes a plurality of uniformly distributed first air holes, centers of the first air holes are concentric, and the circle is concentric with the core layer;
the outer cladding layer is provided with a second annular micro-hole layer, the second annular micro-hole layer comprises a plurality of second air holes which are uniformly distributed, the centers of the second air holes are concentric, and the circle is concentric with the core layer.
In some embodiments, the number of second air holes is twice the number of first air holes;
half of the second air holes are in one-to-one correspondence with the first air holes, so that a connecting line of the circle centers of the second air holes and the corresponding circle centers of the first air holes passes through the circle center of the core layer.
In a second aspect, there is provided a method of making a dispersion compensating optical fiber as described above, comprising the steps of:
providing a pure quartz reaction tube, and depositing or not depositing a pure quartz layer on the inner wall of the pure quartz reaction tube;
then depositing a second sunken cladding layer, an inner cladding layer, a first sunken cladding layer and a core layer in sequence to obtain a doped quartz glass body;
sintering the doped quartz glass body into a solid rod to obtain an optical fiber prefabricated rod;
according to the core cladding ratio, a pure quartz sleeve is sleeved outside the optical fiber prefabricated rod so that the pure quartz sleeve, the pure quartz reaction tube and the pure quartz layer are integrated, or the pure quartz sleeve and the pure quartz reaction tube are integrated to form an outer cladding layer, and drawing is carried out to obtain the dispersion compensation optical fiber.
In some embodiments, the initial flow ratio when depositing the second depressed cladding layer is F: p: si-4: 203: 1000, end flow ratio F: p: si ═ 4.4: 223.3: 1000, parts by weight;
in depositing the inner cladding, the initial flow ratio is F: p: si is 0: 223.3: 1000, end flow ratio F: p: si ═ 0.2: 268: 1000, parts by weight;
in depositing the first depressed cladding layer, the initial flow ratio is F: p: si-12.5: 268: 1000, end flow ratio F: p: si 16.3: 348.4: 1000, parts by weight;
when depositing the core layer, the initial flow ratio is Ge: p: si 324: 348.4: 1000, end flow ratio Ge: p: si 306: 522.6: 1000.
in some embodiments, before drawing, the method further comprises the following steps:
a first annular micro-porous layer is arranged on the first sunken cladding layer and comprises a plurality of first air holes which are uniformly distributed, the centers of the first air holes are concentric, and the circles are concentric with the core layer;
and a second annular micro-hole layer is arranged on the outer cladding layer and comprises a plurality of second air holes which are uniformly distributed, the centers of the second air holes are concentric, and the circles are concentric with the core layer.
The beneficial effect that technical scheme that this application provided brought includes:
the embodiment of the application provides a dispersion compensation optical fiber, the Ge element is reduced in the core layer, the compensation is carried out by putting a setting element with smaller polarizability, and the reduction of attenuation is facilitated.
The doping amount of the setting element in the dispersion compensation fiber is gradually reduced from inside to outside along the radial direction, so that the doping amount of the setting element is ensured to be continuous and has no sudden change, and the advantages of improving the viscosity matching of each layer, reducing the stress concentration in the fiber and improving the attenuation condition of the fiber are achieved.
Compared with Ge element, the doping of the element is set to reduce viscosity and improve flowability better, so that the optical fiber tends to be more uniform in thermal history such as heating and cooling, and nonuniformity caused by local concentration of oxide flowability difference bands is avoided, thereby improving optical fiber attenuation.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic diagram of an end face structure of a dispersion compensating optical fiber according to an embodiment of the present disclosure;
FIG. 2 is a schematic view of a dispersion compensating fiber waveguide structure according to an embodiment of the present disclosure;
FIG. 3 is a schematic diagram illustrating a first curve of a doping amount of a set element according to an embodiment of the present disclosure;
FIG. 4 is a schematic diagram illustrating a second curve of the doping amount of the set element according to an embodiment of the present disclosure;
fig. 5 is a schematic diagram of a third form of curve of the doping amount of the set element according to the embodiment of the present application.
In the figure: 1. a core layer; 2. a first depressed cladding layer; 3. an inner cladding; 4. a second sunken cladding layer; 5. an outer cladding; 6. a first air hole; 7. a second air hole.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The inventors have found, in studies on dispersion compensating optical fibers, that absorption loss, scattering loss, waveguide loss, and the like are main factors affecting the optical fiber loss. For dispersion compensating fibers, scattering loss is the dominant loss form. The optical fiber has rayleigh scattering similar to the scattering phenomenon of light by particles in the atmosphere, the rayleigh scattering of the optical fiber is caused by the density and component change in the optical fiber material, and the main influence factors of the rayleigh scattering are two points: density fluctuations and concentration fluctuations. Wherein, the concentration fluctuation is mainly influenced by the doping concentration of the optical fiber glass part, and theoretically, the smaller the doping amount is, the smaller the scattering loss is; the density fluctuations are related to the inhomogeneities caused by the thermal history during the fiber preparation process, and are also influenced by the viscosity of the fiber glass material, the coefficient of thermal expansion, the relaxation time during cooling.
In addition, light waves are electromagnetic waves, and in the case of glass, light waves are an external alternating electric field, and since various charged particles such as ions, ionic groups and electrons are located inside the glass, when light passes through the glass, polarization deformation of the particles inside the glass is caused. This polarization deformation in glass requires energy from the light wave. Thus, light loses a portion of its energy during its passage through the glass, and the greater the polarizability of the individual ions in the glass, the greater the energy absorbed when the light wave passes through. Reducing the loss of light propagating in an optical fiber can be derived from reducing the "non-uniformity" in the fiber structure, by reducing the degree of polarization, and to some extent, its attenuation.
Based on the above-mentioned research results, the inventors have provided a dispersion compensating fiber having a waveguide structure of a step-type waveguide with a double depressed cladding, as shown in fig. 1 and 2, and specifically, including a core layer 1, a first depressed cladding layer 2, an inner cladding layer 3, a second depressed cladding layer 4, and an outer cladding layer 5, which are arranged in this order from inside to outside in the radial direction; the refractive index of the second depressed cladding 4 is smaller than that of the inner cladding 3 and larger than that of the first depressed cladding 2, and the refractive index of the inner cladding 3 is smaller than that of the core layer 1; the core layer 1 is doped with germanium, the core layer 1, the first depressed cladding layer 2, the inner cladding layer 3 and the second depressed cladding layer 4 are all doped with set elements, the doping amount of the set elements in the dispersion compensation fiber is gradually reduced from inside to outside along the radial direction, and the polarizability of the set elements is smaller than that of the germanium.
In the dispersion compensating fiber according to the above-described embodiment, the use of Ge element is reduced in the core layer, and compensation is performed by using a setting element having a smaller polarizability, which is advantageous in reducing attenuation.
The doping amount of the setting element in the dispersion compensation fiber is gradually reduced from inside to outside along the radial direction, so that the doping amount of the setting element is ensured to be continuous and has no sudden change, and the advantages of improving the viscosity matching of each layer, reducing the stress concentration in the fiber and improving the attenuation condition of the fiber are achieved.
Compared with Ge element, the doping of the element is set to reduce viscosity and improve flowability better, so that the optical fiber tends to be more uniform in thermal history such as heating and cooling, and nonuniformity caused by local concentration of oxide flowability difference bands is avoided, thereby improving optical fiber attenuation.
Typical values for attenuation coefficients in the 1550nm band can be reduced to below 0.45 dB/km.
In some preferred embodiments, the set element comprises one or more of phosphorus P, aluminum Al, alkali metals, magnesium Mg, and beryllium Be.
Preferably, the setting element is phosphorus P, and the oxide of the phosphorus P is used as a main control element for viscosity matching. Phosphorus P is preferred because: in one aspect, P5+The network forms the body ion, its radius is small, the electrovalence is high, it is difficult to receive the external electric field effect to polarize, and restrain the peripheral O tightly2-Electron cloud of ions, O2-The ions are not easily polarized by the action of an external electric field. Therefore, the polarizability of the oxide formed by the P element is lower than that of the oxide formed by the Ge element, which is more favorable for reducing the attenuation.
On the other hand, the P-element oxide has a structure similar to that of the Si-element oxide of the substrate and a similar element molecular weight, and reduces the non-uniformity of the Ge-element oxide compared to the non-uniform distribution of the Ge-element oxide in the optical fiber, thereby improving the attenuation of the optical fiber.
When viscosity matching is carried out, the doping amount of phosphorus P is gradually reduced layer by layer, and abrupt change of doping concentration is avoided, so that the viscosity matching among all layers of the optical fiber is improved, the internal stress of the optical fiber is reduced, and the attenuation loss of the optical fiber is reduced.
When viscosity matching is performed, Ge and P elements act to increase the refractive index in the optical fiber cross section, and simultaneously, F, B elements and F, B elements may be doped to decrease the refractive index in the optical fiber cross section. After the doping amount of the P element is determined, the doping amount of the other elements is determined according to the design of the section structure of the optical fiber, such as Ge, P and F codoping in a core layer and P, F codoping in a cladding layer. If the refractive index after P is doped in the designated layering is lower than that of the profile design, Ge is doped to further increase the refractive index according to the design requirement; in contrast, if the refractive index after doping P is higher than the profile design refractive index, the refractive index is lowered compared to the design upon doping F or B element.
Since the doping amount of the setting element in the dispersion compensating fiber is gradually reduced from inside to outside in the radial direction, that is, a coordinate system in which the doping amount of the setting element is a curve with respect to the distance r can be constructed by selecting a point on the dispersion compensating fiber, taking the distance r between the point and the core layer 1 as the abscissa, and the doping amount of the setting element of the point as the ordinate.
The form of the curve can be various, such as:
in the first curve form, as shown in fig. 3, the curve is a straight line, which has the advantage that the flow meter opening for setting elements such as phosphorus P is stable and the doping process is simple.
In a second form of curve, see fig. 4, the curve is an arc and the absolute value of the slope of the curve decreases from the inside to the outside in the radial direction. The ideal curve is that the doping amount of the set element such as phosphorus P in the core layer 1 is high, the doping amount in each cladding layer is small, the advantage is that the Ge element is doped more in the core layer 1, the attenuation can be improved by doping the set element in the area instead of doping Ge, the Ge is doped less in the cladding layer, the purpose of doping the set element is to adjust the viscosity, and the corresponding doping amount of F or B element can be reduced by doping less set element, so that the cost is limited to be increased.
In a third form of the curve, as shown in fig. 5, the curve includes a first straight line located in the core layer 1, a second straight line located in the first depressed clad layer 2, a third straight line located in the inner clad layer 3, and a fourth straight line located in the second depressed clad layer 4, the first straight line, the second straight line, the third straight line, and the fourth straight line are connected in this order, and the absolute value of the slope of the first straight line > the absolute value of the slope of the second straight line > the absolute value of the slope of the third straight line > the absolute value of the slope of the fourth straight line. The proposal is to approximately replace a smooth curve with a segmented broken line on an ideal curve, each segmented point is arranged on the boundary point of each layer partition, and the flow control of the element doping amount is set in each partition to be in a straight line distribution. The scheme inherits the advantages of the two schemes, the flow control process is relatively simple and convenient, meanwhile, the cost is not greatly improved, and the scheme is more suitable for production practice.
In some preferred embodiments, the relative refractive index difference Δ of the core layer 11% is 1.50% to 2.50%, and the relative refractive index difference Delta of the first depressed clad 22% of-1.2% -0%, relative refractive index difference delta of inner cladding 33% of-0.2% to 10%, relative refractive index difference Delta of the second depressed clad layer 44% is-0.5% -0%, and the outer cladding 5 is made of pure quartz.
Wherein, the relative refractive index difference Δ% is calculated by the following formula:
Figure BDA0003243723120000081
wherein n is0When i is 1, n is the refractive index of pure quartz glass1When i is 2, n is the refractive index of the core layer 12When the refractive index of the first depressed clad layer 2, i, is 3, n3When the refractive index of the inner cladding 3, i is 4, n4The refractive index of the second depressed cladding 4.
The outer diameter of the core layer 1 is 3-9 mm, the outer diameter of the first sunken cladding layer 2 is 15-27 mm, the outer diameter of the inner cladding layer 3 is 25-40 mm, and the outer diameter of the second sunken cladding layer 4 is 36-52 mm.
Referring to fig. 1, in some preferred embodiments, a first annular microporous layer is disposed on the first lower clad layer 2, the first annular microporous layer includes a plurality of first air holes 6 uniformly distributed, centers of the first air holes 6 are concentric, and the circle is concentric with the core layer 1; the outer cladding layer 5 is provided with a second annular micro-hole layer, the second annular micro-hole layer comprises a plurality of second air holes 7 which are uniformly distributed, the centers of the second air holes 7 are concentric, and the circle is concentric with the core layer 1.
In the embodiment, the bending-resistant structure design is further added on the original bending resistance by matching the air hole structure in the deep sunken cladding and the outer cladding region of the optical fiber, so that the bending resistance of the optical fiber can be further improved.
Theoretically, the more the air holes are arranged, the higher the air filling rate is, the higher the bending resistance is improved, but the production is limited by the limitation of the optical fiber profile structure, the air holes cannot be densely filled as theoretically designed, otherwise, the core rod profile structure is damaged to a certain extent, the optical fiber strength is deteriorated, the production cost is greatly improved, and the production efficiency is reduced. Therefore, in this embodiment, the air holes are formed in the first depressed clad layer and the outer clad layer, thereby improving the bending resistance and preventing the strength of the optical fiber from being deteriorated.
The air holes may be circular, but other shaped air hole structures are not excluded.
Preferably, the first air hole size provided in the first depressed cladding region does not exceed the first depressed cladding region, thereby avoiding degradation of fiber performance, but does not preclude the use of this region beyond the particular use.
Preferably, the first air holes have an air filling rate of 50% or more, which is advantageous for the effectiveness of the air holes, and the use of a filling rate lower than this level in a special use is not excluded.
The air filling rate S can be calculated using the following formula:
Figure BDA0003243723120000091
wherein the diameter d is the diameter of the air holes, N is the number of the air holes, RinRadius of the inscribed circle of the air hole, RoutThe radius of the circumscribed circle of the air hole.
Preferably, the size of the second air hole is slightly larger than the size of the gap between two adjacent first air holes, which does not exclude other arrangement methods in special use occasions.
Referring to fig. 1, in some preferred embodiments, the number of the second air holes 7 is twice the number of the first air holes 6, wherein half of the second air holes 7 correspond to the first air holes 6 one by one, so that a connection line between the circle centers of the second air holes 7 and the circle center of the corresponding first air hole 6 passes through the circle center of the core layer 1, which can ensure that the center line of the gap between two first air holes 6 passes through the circle center of the second air hole 7. The refractive index of each segmented cladding is adjusted by the multi-layer auxiliary hole structure and the PCVD process, so that the performance index of the optical fiber is met, and the bending resistance is improved.
For example, in one embodiment, the first air holes 6 have a diameter of 8mm, a number of 16, and an air filling ratio of 58%, and the second air holes 7 have a diameter of 10mm, and a number of 32, and the dispersion compensating fiber has a bending resistance of less than or equal to 0.004dB/m for a bending loss of 50mm in diameter and less than or equal to 0.042dB/m for a bending loss of 20mm in diameter in a 1550nm window.
The application also provides a preparation method of the dispersion compensation optical fiber, which comprises the following steps:
providing a pure quartz reaction tube, and depositing or not depositing a pure quartz layer on the inner wall of the pure quartz reaction tube;
then depositing a second sunken cladding layer 4, an inner cladding layer 3, a first sunken cladding layer 2 and a core layer 1 in sequence to obtain a doped quartz glass body;
sintering the doped quartz glass body into a solid rod to obtain an optical fiber preform;
according to the core cladding ratio, a pure quartz sleeve is sleeved on the optical fiber prefabricated rod, so that when a pure quartz layer is deposited, the pure quartz sleeve, the pure quartz reaction tube and the pure quartz layer form an outer cladding layer 5 as a whole, or when the pure quartz layer is not deposited, the pure quartz sleeve and the pure quartz reaction tube form the outer cladding layer 5 as a whole, and drawing is carried out, so that the dispersion compensation optical fiber is obtained.
Wherein, when depositing the second sunken cladding layer 4, the initial flow ratio is F: p: si-4: 203: 1000, end flow ratio F: p: si ═ 4.4: 223.3: 1000, the opening degree of the flowmeter corresponding to the F and the opening degree of the flowmeter corresponding to the P are linearly changed;
at the time of inner cladding 3 deposition, the initial flow ratio is F: p: si is 0: 223.3: 1000, end flow ratio F: p: si ═ 0.2: 268: 1000, the opening degree of the flowmeter corresponding to the F and the opening degree of the flowmeter corresponding to the P are linearly changed;
in depositing the first depressed cladding layer 2, the initial flow ratio is F: p: si-12.5: 268: 1000, end flow ratio F: p: si 16.3: 348.4: 1000, the opening degree of the flowmeter corresponding to the F and the opening degree of the flowmeter corresponding to the P are linearly changed;
in depositing the core layer 1, the initial flow ratio is Ge: p: si 324: 348.4: 1000, end flow ratio Ge: p: si 306: 522.6: 1000, the opening degree of the flowmeter corresponding to Ge and the opening degree of the flowmeter corresponding to P are linearly changed.
Further, before drawing, the method also comprises the following steps:
a first annular micro-porous layer is arranged on the first sunken cladding layer 2 and comprises a plurality of first air holes 6 which are uniformly distributed, the centers of the first air holes 6 are concentric, and the circles are concentric with the core layer 1;
and a second annular micro-hole layer is arranged on the outer cladding layer 5 and comprises a plurality of second air holes 7 which are uniformly distributed, the centers of the second air holes 7 are concentric, and the circle is concentric with the core layer 1.
In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A dispersion compensating optical fiber, characterized by: the composite material comprises a core layer (1), a first sunken cladding layer (2), an inner cladding layer (3), a second sunken cladding layer (4) and an outer cladding layer (5) which are sequentially arranged from inside to outside along the radial direction;
the refractive index of the second depressed cladding (4) is smaller than that of the inner cladding (3) and larger than that of the first depressed cladding (2);
the core layer (1) is doped with germanium, the core layer (1), the first depressed cladding layer (2), the inner cladding layer (3) and the second depressed cladding layer (4) are all doped with set elements, the doping amount of the set elements in the dispersion compensation optical fiber is gradually reduced from inside to outside along the radial direction, and the polarizability of the set elements is smaller than that of the germanium.
2. The dispersion compensating optical fiber of claim 1, wherein:
the set elements include one or more of phosphorus P, aluminum Al, alkali metals, magnesium Mg, and beryllium Be.
3. The dispersion compensating optical fiber of claim 1, wherein:
the doping amount of the set element is in a curve;
the curve is a straight line; or, the curve is an arc line, and the absolute value of the slope of the curve gradually decreases from inside to outside along the radial direction; or the curve comprises a first straight line positioned on the core layer (1), a second straight line positioned on the first sunken cladding layer (2), a third straight line positioned on the inner cladding layer (3) and a fourth straight line positioned on the second sunken cladding layer (4), the first straight line, the second straight line, the third straight line and the fourth straight line are sequentially connected, and the absolute value of the slope of the first straight line is larger than the absolute value of the slope of the second straight line and larger than the absolute value of the slope of the third straight line and larger than the absolute value of the slope of the fourth straight line.
4. The dispersion compensating optical fiber of claim 1, wherein:
the relative refractive index difference Delta of the core layer (1)1% is 1.50-2.50%, and the relative refractive index difference Delta of the first depressed clad layer (2)2% of-1.2% -0%, and the relative refractive index difference delta of the inner cladding (3)3% of-0.2% to 10%, relative refractive index difference Delta of the second depressed clad layer (4)4% is-0.5% -0%.
5. The dispersion compensating optical fiber of claim 1, wherein:
the outer diameter of the core layer (1) is 3-9 mm, the outer diameter of the first sunken cladding layer (2) is 15-27 mm, the outer diameter of the inner cladding layer (3) is 25-40 mm, and the outer diameter of the second sunken cladding layer (4) is 36-52 mm.
6. The dispersion compensating optical fiber of claim 1, wherein:
a first annular micro-porous layer is arranged on the first sunken cladding layer (2), the first annular micro-porous layer comprises a plurality of first air holes (6) which are uniformly distributed, the centers of the first air holes (6) are concentric, and the circle is concentric with the core layer (1);
the outer cladding layer (5) is provided with a second annular micro-hole layer, the second annular micro-hole layer comprises a plurality of second air holes (7) which are uniformly distributed, the circle centers of the second air holes (7) are concentric, and the circle is concentric with the core layer (1).
7. The dispersion compensating optical fiber of claim 6, wherein:
the number of the second air holes (7) is twice that of the first air holes (6);
half of the second air holes (7) are in one-to-one correspondence with the first air holes (6), so that a line connecting the circle centers of the second air holes (7) and the corresponding circle centers of the first air holes (6) passes through the circle center of the core layer (1).
8. A method of making a dispersion compensating optical fiber according to claim 1, comprising the steps of:
providing a pure quartz reaction tube, and depositing or not depositing a pure quartz layer on the inner wall of the pure quartz reaction tube;
then depositing a second sunken cladding (4), an inner cladding (3), a first sunken cladding (2) and a core layer (1) in sequence to obtain a doped quartz glass body;
sintering the doped quartz glass body into a solid rod to obtain an optical fiber prefabricated rod;
according to the core cladding ratio, a pure quartz sleeve is sleeved outside the optical fiber prefabricated rod so that the pure quartz sleeve, the pure quartz reaction tube and the pure quartz layer are integrated, or the pure quartz sleeve and the pure quartz reaction tube are integrated to form an outer cladding layer (5), and drawing is carried out to obtain the dispersion compensation optical fiber.
9. The method of claim 8, wherein:
in depositing the second depressed cladding (4), the initial flow ratio is F: p: si-4: 203: 1000, end flow ratio F: p: si ═ 4.4: 223.3: 1000, parts by weight;
in depositing the inner cladding (3), the initial flow ratio is F: p: si is 0: 223.3: 1000, end flow ratio F: p: si ═ 0.2: 268: 1000, parts by weight;
in depositing the first depressed cladding (2), the initial flow ratio is F: p: si-12.5: 268: 1000, end flow ratio F: p: si 16.3: 348.4: 1000, parts by weight;
in depositing the core layer (1), the initial flow ratio is Ge: p: si 324: 348.4: 1000, end flow ratio Ge: p: si 306: 522.6: 1000.
10. the method of claim 8, further comprising, prior to drawing, the steps of:
a first annular micro-porous layer is arranged on the first sunken cladding layer (2), the first annular micro-porous layer comprises a plurality of first air holes (6) which are uniformly distributed, the centers of the first air holes (6) are concentric, and the circle is concentric with the core layer (1);
and a second annular micro-hole layer is arranged on the outer cladding layer (5), the second annular micro-hole layer comprises a plurality of second air holes (7) which are uniformly distributed, the centers of the second air holes (7) are concentric, and the circle is concentric with the core layer (1).
CN202111026517.4A 2021-09-02 2021-09-02 Dispersion compensation optical fiber and preparation method thereof Pending CN113866867A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111026517.4A CN113866867A (en) 2021-09-02 2021-09-02 Dispersion compensation optical fiber and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111026517.4A CN113866867A (en) 2021-09-02 2021-09-02 Dispersion compensation optical fiber and preparation method thereof

Publications (1)

Publication Number Publication Date
CN113866867A true CN113866867A (en) 2021-12-31

Family

ID=78989229

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111026517.4A Pending CN113866867A (en) 2021-09-02 2021-09-02 Dispersion compensation optical fiber and preparation method thereof

Country Status (1)

Country Link
CN (1) CN113866867A (en)

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5799123A (en) * 1995-10-20 1998-08-25 The Furukawa Electric Co., Ltd. Dispersion compensating fiber
CN1261157A (en) * 1999-01-18 2000-07-26 三星电子株式会社 Optical waveguides and manufacture thereof
WO2001038243A1 (en) * 1999-11-24 2001-05-31 Corning Incorporated Method for radially consolidating a porous optical fiber preform
CN102243336A (en) * 2011-07-25 2011-11-16 长飞光纤光缆有限公司 Dispersion compensation fiber
CN102354019A (en) * 2011-11-11 2012-02-15 烽火通信科技股份有限公司 Bent non-sensitive micro-structured optical fiber and production method thereof
CN102445436A (en) * 2011-10-18 2012-05-09 华中科技大学 Microstructure fiber sensor
CN102998739A (en) * 2011-09-14 2013-03-27 住友电气工业株式会社 Optical fiber
CN105911639A (en) * 2016-05-24 2016-08-31 长飞光纤光缆股份有限公司 Low-attenuation single-mode optical fiber
CN106772785A (en) * 2017-03-23 2017-05-31 北京交通大学 Optical fiber structure with air shield
CN109073824A (en) * 2016-05-10 2018-12-21 住友电气工业株式会社 Coupled mode multi-core optical fiber and optical transmission system including coupled mode multi-core optical fiber
CN109298482A (en) * 2018-11-28 2019-02-01 长飞光纤光缆股份有限公司 A kind of large-effective area single mode fiber of low decaying and low bend loss
CN110515153A (en) * 2019-09-25 2019-11-29 南京邮电大学 A kind of low dispersion OAM mould transmission fiber
CN112305664A (en) * 2020-10-19 2021-02-02 江苏法尔胜光电科技有限公司 Multipurpose polarization maintaining optical fiber and preparation method thereof

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5799123A (en) * 1995-10-20 1998-08-25 The Furukawa Electric Co., Ltd. Dispersion compensating fiber
CN1261157A (en) * 1999-01-18 2000-07-26 三星电子株式会社 Optical waveguides and manufacture thereof
WO2001038243A1 (en) * 1999-11-24 2001-05-31 Corning Incorporated Method for radially consolidating a porous optical fiber preform
CN102243336A (en) * 2011-07-25 2011-11-16 长飞光纤光缆有限公司 Dispersion compensation fiber
CN102998739A (en) * 2011-09-14 2013-03-27 住友电气工业株式会社 Optical fiber
CN102445436A (en) * 2011-10-18 2012-05-09 华中科技大学 Microstructure fiber sensor
CN102354019A (en) * 2011-11-11 2012-02-15 烽火通信科技股份有限公司 Bent non-sensitive micro-structured optical fiber and production method thereof
CN109073824A (en) * 2016-05-10 2018-12-21 住友电气工业株式会社 Coupled mode multi-core optical fiber and optical transmission system including coupled mode multi-core optical fiber
CN105911639A (en) * 2016-05-24 2016-08-31 长飞光纤光缆股份有限公司 Low-attenuation single-mode optical fiber
CN106772785A (en) * 2017-03-23 2017-05-31 北京交通大学 Optical fiber structure with air shield
CN109298482A (en) * 2018-11-28 2019-02-01 长飞光纤光缆股份有限公司 A kind of large-effective area single mode fiber of low decaying and low bend loss
CN110515153A (en) * 2019-09-25 2019-11-29 南京邮电大学 A kind of low dispersion OAM mould transmission fiber
CN112305664A (en) * 2020-10-19 2021-02-02 江苏法尔胜光电科技有限公司 Multipurpose polarization maintaining optical fiber and preparation method thereof

Similar Documents

Publication Publication Date Title
US5942296A (en) Optical fiber preform
EP2700988B1 (en) Bending-resistant large core diameter high numerical aperture multimode fiber
EP1813581B1 (en) Method for manufacturing an optical fiber preform, optical fiber preform and optical fiber
US8295668B2 (en) Low loss optical fiber designs and methods for their manufacture
EP1876150A1 (en) Radiation-resistant fluorine doped optical fiber
CN101811822B (en) Method for manufacturing large-diameter optical fiber mandril through PCVD process
US20060018614A1 (en) High performance dispersion compensating optical fibers and manufacturing method for the same
FI81209B (en) ENMODS OPTICAL VAOGROERSFIBER OCH FOERFARANDET FOER FRAMSTAELLNING AV DESS.
KR20140016980A (en) Bending insensitive single mode optical fibre
CN103543491A (en) Ultralow-loss high-bandwidth irradiation-resistance multimode fiber and manufacturing method thereof
US8820121B2 (en) Method of manufacturing optical fiber base material
CN102225843A (en) Method for producing fiber prefabricated rod
KR101720138B1 (en) Method and tubular semi-finished product for producing an optical fiber
CN113866867A (en) Dispersion compensation optical fiber and preparation method thereof
EP2784034B1 (en) Process for making large core multimode optical fibers
CN110937796B (en) Method for manufacturing broadband multimode optical fiber preform
US20020000104A1 (en) Methods of making preform and optical fiber
CN110981183B (en) Manufacturing method of broadband multimode optical fiber preform
CN114265144A (en) Short-wavelength low-loss polarization-maintaining optical fiber and application and preparation method thereof
CN113848608B (en) Single-mode optical fiber and preparation method thereof
CN114637068B (en) Gain-balanced few-mode erbium-doped optical fiber and preparation method thereof
CN114779394B (en) Normal dispersion thulium-doped single-mode optical fiber, preparation method thereof and laser
CN117369041A (en) Boron-germanium co-doped polarization-maintaining photosensitive fiber and preparation method thereof
CN115140932A (en) Bending insensitive single-mode fiber and preparation method thereof
CN117406336A (en) Radiation-resistant 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