Method for manufacturing non-zero dispersion shift optical fiber preforms and the resulting preforms and optical fibers

Abstract

This invention relates to a method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform, as well as the resulting preform and optical fiber. The method includes depositing an inner cladding and a core layer. The inner cladding and multiple core layers are deposited inside a quartz tube using PCVD (Polycarbonyl Variation) technology. The preform is then fused together to form a core rod. The deposited tube is heated and fused together in a fusion lathe to form a core rod containing both the core and inner cladding. The heating and fusion process is adjusted by controlling the axial movement speed and output power of the furnace to regulate the outer diameter and out-of-roundness of the fused core rod. The core rod is then externally deposited with a pure silica cladding using OVD (Optical Variation) technology, or fitted with a pure silica outer tube. Finally, through sintering or fusion processing, a non-zero dispersion-shifted single-mode optical fiber preform is produced. This invention not only ensures the accuracy of the deposition process but also improves the quality of the core rod fusion process, thereby achieving precise core rod manufacturing and further optimizing optical fiber performance.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a non-zero dispersion-shifted optical fiber preform, as well as the resulting preform and optical fiber, belonging to the field of optical communication and transmission technology. Background Technology

[0002] In the field of optical fiber communication, non-zero dispersion-shifted single-mode fiber (NZ-DSF) is a key technology developed to address the limitations of traditional optical fibers in wavelength division multiplexing (WDM) systems. Traditional single-mode fiber (corresponding to ITU-T standard G.652 fiber) has zero dispersion in the 1310nm window, but exhibits high dispersion (approximately 17 ps / (nm·km)) in the 1550nm window, limiting long-distance transmission rates. Although the loss is lower in the 1550nm window (approximately 0.2 dB / km), dispersion causes signal pulse broadening, requiring frequent use of dispersion compensation modules. Dispersion-shifted DSF fiber (corresponding to ITU-T standard G.653 fiber) uses waveguide design to shift the zero-dispersion point from 1310nm to 1550nm, reducing dispersion in the 1550nm window. However, this characteristic induces severe four-wave mixing (FWM) nonlinearity in WDM systems, leading to inter-channel crosstalk and limiting the application of dense wavelength division multiplexing (DWDM). Non-zero dispersion-shifted fiber (G.655) is an optical fiber developed for DWDM transmission technology. It overcomes the problems of large dispersion in G.652 fiber (non-dispersion-shifted fiber) and severe four-wave mixing in G.653 fiber (dispersion-shifted fiber) at a low-loss wavelength of 1550nm, making it the preferred fiber type for operator-related optical fiber communication systems.

[0003] Non-zero dispersion shift fiber preforms consist of three parts: a core layer, an inner cladding layer, and an outer cladding layer. The core layer comprises 2-4 layers with different refractive index distributions, and the inner cladding layer also comprises 2-4 layers with different refractive index distributions. The outer cladding layer is a pure silica glass layer. Due to the complex refractive index profile structure of the core layer and inner cladding layer, especially the small diameter of the core layer and the narrow control range of diameter and refractive index, requiring high precision, in-tube plasma chemical vapor deposition (IPVD) is generally used to deposit the core layer and inner cladding layer by layer, obtaining a core rod with the core layer and inner cladding layer integrated. This core rod is then fitted with an outer cladding glass provided by external vapor deposition (OVD) technology to form a complete fiber preform. For IPVD, a sintering process is always required to solidify the deposition tube into a solid core rod. Existing sintering and shrinking processes are prone to uneven rod diameter due to the uncertainty of the glass softening point and the slow change in furnace heating effect over time. This can lead to problems such as excessive core non-roundness or localized air loops (incomplete sintering at the center) after solidifying the core, resulting in product scrap. Lower sintering and shrinking temperatures easily cause localized air loops; while higher temperatures can reduce air loops, they can lead to excessive core non-roundness and even increased bow value, both significantly reducing the effective rod length. Excessive core non-roundness has a more severe impact on small-diameter core rods, such as those for non-zero dispersion fibers, easily causing fiber geometry parameters or PMD (partial deviation modulus) to exceed limits. Therefore, the production process of non-zero dispersion shift single-mode fiber core rods requires not only precise control of the deposition process of each core cladding layer but also ensuring quality control during the core rod sintering and shrinking process. Summary of the Invention

[0004] The technical problem to be solved by this invention is to address the shortcomings of the existing technology by proposing a method for manufacturing a non-zero dispersion shift single-mode optical fiber preform, as well as the preform and optical fiber obtained therefrom. This method not only ensures the accuracy of the deposition process but also improves the quality of the core rod melting and shrinking process, thereby achieving precise manufacturing of the core rod and further optimizing the performance of the optical fiber.

[0005] The manufacturing method adopted by this invention to solve the above-mentioned problems is as follows:

[0006] The inner cladding and core layers are deposited. Using a quartz tube, a PCVD process is employed to deposit the inner cladding and multiple core layers of a non-zero dispersion-shifted optical fiber preform core. The multiple core layers consist of 2 to 4 layers, with the relative refractive index difference decreasing layer by layer. The relative refractive index difference ranges from 0.2% to 0.7%, and the core diameter ranges from 4 to 10 mm.

[0007] The mandrel is fabricated by melting and shrinking the deposited tube, after the inner cladding and core layers have been deposited, into a mandrel containing both the core and inner cladding layers in a melting and shrinking lathe. The outer diameter and out-of-roundness of the mandrel are adjusted by controlling the axial movement speed and output power of the heating furnace during the melting and shrinking process.

[0008] To fabricate an optical fiber preform, a pure silica cladding layer is deposited on the core rod using the OVD process, or a pure silica outer tube is fitted over the core rod. Through sintering or melting and shrinking treatment, a non-zero dispersion shift optical fiber preform is fabricated.

[0009] According to the above scheme, the heating and shrinking process involves adding rod diameter measuring instruments to both sides of the heating furnace on the shrinking lathe, and installing pressure sensors at both ends of the shrinking deposition tube. The deposition tube is installed on the lathe, and the heating furnace is moved while rotating. Through 2 to 6 shrinking passes, the rod diameter is gradually reduced while maintaining uniformity until a suitable and uniform center aperture is obtained. The last pass is the solidification pass. During each shrinking pass, the change in rod diameter before and after shrinking is measured to form the axial distribution curve of the rod diameter for each pass. At the same time, the shrinking pressure is recorded and controlled to match the rod diameter. Then, the power and speed of the heating furnace are dynamically adjusted, and the pressure is controlled to effectively improve the roundness while avoiding gas line problems.

[0010] According to the above scheme, based on the difference between the average value and the target value in the middle region of the deposition tube diameter, the heating furnace power of the subsequent melting and shrinking passes is adjusted. Based on the local changes in the tube diameter, the heating furnace speed at the corresponding position in the next pass is adjusted to ensure uniform melting and shrinkage of the tube diameter.

[0011] According to the above scheme, the roundness of the precast mandrel is improved by matching the rod diameter and the melting pressure.

[0012] According to the above scheme, the temperature of the heating furnace is controlled at 1600℃~2200℃, the axial movement speed of the heating furnace in the melting and shrinking firing process is 10~30mm / min, and the rotation speed of the deposition tube is 15~35 rad / min; the heating furnace is a graphite resistance heating furnace or induction furnace, the heating axial region is 100~350mm, and the circumferential gap between the heating furnace sleeve and the deposition tube is filled with protective gas. The protective gas is an inert gas such as Ar or He.

[0013] According to the above scheme, the relative pressure (relative to atmospheric pressure) of the melting and shrinking process is controlled within the range of ±30 Pa, and the relative pressure of the burning process is controlled within the range of -500 Pa to -990 Pa.

[0014] According to the above scheme, the quartz liner is a doped quartz glass tube with a wall thickness of 6~9mm. The relative refractive index difference is gradually distributed, with the inner surface being higher and the outer surface being lower, and it is convex upward. The relative refractive index difference of the inner surface (inner edge of the inner cladding) of the liner is 0.1~0.2%, and the relative refractive index difference of the outer surface (outer edge of the inner cladding) is -0.2~0%.

[0015] According to the above scheme, the outer cladding wall thickness of the optical fiber preform is 35~60mm.

[0016] According to the above scheme, the core layer of the optical fiber preform core rod has 3 layers. The relative refractive index difference Δn1 of the first core layer (outermost layer) is 0.15~0.25% and the diameter is 7~9mm. The relative refractive index difference Δn2 of the second core layer (middle layer) is 0.34~0.45% and the diameter is 5~7mm. The relative refractive index difference Δn3 of the third core layer (innermost layer) is 0.5~0.6% and the diameter is 3~5mm.

[0017] According to the above scheme, the inner cladding of the optical fiber preform core rod has two layers. The relative refractive index difference Δn4 of the first inner cladding layer is -0.1~0% and the diameter is 15~17 mm. The second inner cladding layer is composed of a quartz liner.

[0018] According to the above scheme, the typical value of the core non-roundness of the optical fiber preform core is 0.4%.

[0019] The non-zero dispersion shift optical fiber preform of the present invention is manufactured according to the above scheme, that is, it is formed by combining a core rod and an outer cladding or a pure silica outer tube.

[0020] The non-zero dispersion shifted optical fiber of the present invention is drawn into fibers from an optical fiber preform manufactured by the above scheme through a drawing tower.

[0021] According to the above scheme, the non-zero dispersion shifted fiber has an attenuation of ≤0.5dB / km at the 1383nm band, an attenuation of ≤0.195dB / km at the 1550nm band, and an attenuation of ≤0.200dB / km at the 1625nm band.

[0022] According to the above scheme, the non-zero dispersion shifted fiber has a dispersion slope of ≤0.075ps / (nm²·km), a zero dispersion wavelength of ≤1520nm, a dispersion of 2~6ps / (nm·km) in the range of 1530nm~1565nm, and a dispersion of 4.5~11.2ps / (nm·km) in the range of 1565nm~1625nm.

[0023] According to the above scheme, the non-zero dispersion shifted fiber has a mode field diameter of 9.2μm-10μm at a wavelength of 1550nm, a cabling cutoff wavelength of ≤1450nm, and a bending loss of ≤0.03dB in the test of 100 turns of 60mm diameter fiber bending performance.

[0024] The beneficial effects of this invention are as follows: 1. The PCVD process ensures deposition processing precision, and the improved core rod shrinkage process enhances the quality of the shrinkage process, reducing core rod out-of-roundness and curvature, thereby achieving precise core rod manufacturing. The fabricated optical fiber can find a better balance among dispersion, nonlinear effects, and bending loss, further optimizing fiber performance. 2. The shrinkage process automatically corrects local diameter fluctuations by locally adjusting axial movement speed and output power changes, maintaining uniform center aperture of the deposition tube throughout the shrinkage process. Simultaneously, controlling the shrinkage pressure effectively maintains the roundness and core roundness of the deposition tube during the gradual reduction of the core diameter. A certain pressure difference is maintained between the inside and outside of the tube during the burn-in process, with the relative pressure controlled between -500 and -999 Pa, ensuring both normal burn-in and further guaranteeing core roundness. 3. The liner in this invention adopts an upwardly convex graded refractive index distribution. Since the inner cladding of the non-zero dispersion-shifted fiber plays a role in regulating the fiber's dispersion characteristics, mode field distribution, and bending loss, the resulting second inner cladding simplifies the multi-layered stepped structure and achieves a better balance among dispersion, nonlinear effects, and bending loss. 4. The fabricated non-zero dispersion-shifted fiber preform has an innermost core layer with the highest refractive index for strong beam confinement. Outside, there are 2-3 progressively decreasing stepped core layers for fine-tuning waveguide dispersion and effective mode field diameter. The stepped core layers form the main waveguide, and the liner forms the second inner cladding. A refractive index-enhanced region is first formed at the first cladding layer to attract mode field concentration and increase the effective area. Subsequently, the refractive index gradually decreases, providing a continuous optical barrier, allowing the mode field to transition more smoothly to the outside. This ensures both an increase in effective area and shielding against bending leakage. Furthermore, the convex gradient distribution makes the change of dn / dr in the refractive index rise region smoother, and the waveguide dispersion is less dependent on wavelength, thus obtaining a lower dispersion slope. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the radial structure of the non-zero dispersion shifted optical fiber preform of the present invention.

[0026] Figure 2 This is a schematic diagram of the refractive index profile of the non-zero dispersion-shifted optical fiber of the present invention.

[0027] Figure 3 This is a schematic diagram of the melting and shrinking lathe and melting and shrinking process of the present invention.

[0028] Figure 4 This is a comparison diagram of the non-roundness of the core of the present invention and that of existing melt-shrink mandrels.

[0029] Figure 5 This is a comparison chart of the statistical distribution of the non-roundness of the core of the present invention and that of existing melt-shrink mandrels.

[0030] Figure 6This is a comparison diagram of PMD (Polarization Method) of optical fibers drawn from the present invention and those drawn from existing fusion-shrink core rods. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] One embodiment of the present invention is as follows: Figures 1-6 As shown, a 6.5mm thick quartz liner tube is selected. The liner tube is a doped quartz glass tube with a gradually changing relative refractive index difference, higher inside and lower outside, and convex upward. The relative refractive index difference on the inner surface (inner edge of the inner cladding) is 0.2%, and the relative refractive index difference on the outer surface (outer edge of the inner cladding) is -0.1%. One cladding layer and three core layers X1 are deposited using PCVD technology. The refractive index of the core layers decreases layer by layer. The relative refractive index difference of the three core layers ranges from 0.3% to 0.7%. There are two inner cladding layers. The first inner cladding layer X2 is a deposited inner cladding layer, and the second inner cladding layer X3 is composed of the quartz liner tube. After deposition, the core is shrunk in a shrinking equipment to obtain a mandrel with a diameter of 29.4mm. After shrinking, a mandrel containing the core layer and inner cladding layer is formed as a whole. The core rod is then externally deposited with a pure silica cladding layer X4 using an OVD process, and sintered to form a pure silica cladding layer with a wall thickness of 55mm, thus producing a non-zero dispersion shift single-mode optical fiber preform. Alternatively, the core rod can be fitted with an outer pure silica sheath, and through a shrink-fit process, a pure silica cladding layer with a wall thickness of 55mm can be formed, thus producing a complete optical fiber preform.

[0033] The melting and shrinking process is as follows: The deposition tube 1 is installed as a whole on the melting and shrinking sintering lathe. The rotating chucks 7 and 8 at both ends fix the deposition tube in place, ensuring it is centered in the heating furnace 2. The rotating chucks 7 and 8 are respectively equipped with an inlet pressure gauge 5 and an outlet pressure gauge 6. Protective gas is extracted from the inlet end of the rotating chuck 7 through the deposition tube through-hole 9 and from the outlet end of the rotating chuck 8. The rotating chucks are then turned on, allowing them to rotate synchronously at both ends, resulting in a uniform rotation of the deposition tube. The reciprocating motion of the heating furnace 2 outside the deposition tube 1 provides the heat source for melting and shrinking sintering. When the temperature of the heating element reaches 1900℃, the first melting and shrinking cycle begins. Oxygen enters the deposition tube from the inlet end through the rotating chuck 7, maintaining a slight positive pressure inside the tube. After melting and shrinking begins, as the heating furnace moves from left to right, the diameter gauge 4 measures the diameter distribution of the deposition tube before melting and shrinking, and the diameter gauge 3 measures the diameter distribution of the deposition tube after melting and shrinking. The difference at the same position represents the change in diameter at the current speed and power. If the average diameter of the middle 50% area of ​​the diameter gauge 3 is larger (or smaller) than the target diameter for the corresponding pass, the heating furnace power is increased (or decreased) accordingly during the return trip (when the heating furnace moves from right to left) to bring the radial target value of the bars closer in the next pass. This achieves automatic correction of the heating power. If the diameter gauge 3 is larger (or smaller) in the 790-810mm range during the first pass, the heating furnace travel speed is reduced (or increased) in the 790-810mm area during the second pass to correct local differences in bar diameter and achieve uniform bar diameter.

[0034] The automatic power adjustment correction calculation method is as follows:

[0035] The power Pn of the nth melting and shrinking pass is calculated as follows:

[0036] P n =P n-1 +P mm *(D) n-1目标 –D n实际 ) / (D n-1目标 –D n目标 ), (n≥2)

[0037] In the formula:

[0038] P n Power of the heating furnace in the nth pass, kW; P mm Power correction factor (determined based on different types of mandrels), kW;

[0039] D n目标 : Target bar diameter for the nth pass, in mm; D n实际 : Measured bar diameter for the nth pass, in mm;

[0040] Example: When n=2, P1 is 15kW, P mm The value is 0.6 kW. If the target bar diameter D for the first pass is... 1目标 The target bar diameter D for the second pass is 36mm. 2目标 The actual bar diameter D after the first melting and shrinking process is 34.5mm. 2实际 The thickness is 35mm, so the power for the second pass can be calculated.

[0041] P2=15+0.6*(36-35) / (36-34.5)=15.2kw

[0042] The calculation method for automatic speed adjustment is as follows:

[0043] Centered on the maximum diameter variation of 800mm, the velocity increment is superimposed in the surrounding area, and the calculation method is as follows:

[0044] Vmax = VN + Vmm*(D avg - DT)

[0045] In the formula:

[0046] VN: Original speed setting, mm / min

[0047] V mm Speed ​​correction factor (determined based on different types of mandrels), mm / min

[0048] D avg Average bar diameter, mm

[0049] DT: Local extreme value of rod diameter, mm

[0050] Example: When the original speed VN is set to 25 mm / min, the average bar diameter D avg The local extreme value of the rod diameter DT at 34.5mm and 800mm is 35.5mm. If Vmm is 3.0kW, calculate the maximum rate of change.

[0051] Vmax = 25+3.0*(34.5-35.5)= 22 mm / min

[0052] The heating furnace begins uniform deceleration at a position of 800-100 (RL) = 700 mm. Within the 700 mm to 800 mm range, the speed decreases from 25 mm / min to 22 mm / min. Then, it begins uniform acceleration, increasing to 25 mm / min within a 50 (RR) mm range, i.e., the 800-850 mm region. RL represents the left speed change range, and RR represents the right speed change range.

[0053] The core layer out-of-roundness of the mandrel obtained by the melting and shrinking method of the present invention can be significantly improved, with a typical value decreasing from 1.2% to below 0.4%. Figure 5 Under the same drawing conditions, the polarization mode dispersion of the drawn optical fiber can be reduced by approximately 25%. Figure 6 )

[0054] In this embodiment, the preform was drawn into fibers using a drawing tower at a drawing speed of 1500 m / min. The parameters of the resulting non-zero dispersion-shifted optical fiber are as follows: the relative refractive index difference Δn1 of the first core layer is 0.18% and the diameter is 6.3 μm; the relative refractive index difference Δn2 of the second core layer is 0.44% and the diameter is 5.2 μm; the relative refractive index difference Δn3 of the third core layer is 0.58% and the diameter is 4.3 μm. The relative refractive index difference Δn4 of the first inner cladding is -0.15% and the diameter is 12.6 μm; the relative refractive index difference Δn5 of the inner surface of the second inner cladding is 0.2%; the relative refractive index difference Δn6 of the outer surface is -0.1% and the diameter is 24.1 μm; and the outer cladding is a pure silica glass cladding. The optical fiber exhibits attenuation of 0.349 dB / km at 1383 nm, 0.193 dB / km at 1550 nm, and 0.199 dB / km at 1625 nm. Its dispersion slope is 0.0717 ps / (nm²·km), with a zero-dispersion wavelength of 1484 nm. Dispersion ranges from 3.23 to 5.74 ps / (nm·km) in the 1530 nm to 1565 nm range and from 5.74 to 10 ps / (nm·km) in the 1565 nm to 1625 nm range. The mode field diameter at 1550 nm is 9.37 μm, and the cabling cutoff wavelength is 1288 nm. In a test involving 100 turns of a 60 mm diameter fiber, the bending loss is 0.011 dB.

Claims

1. A method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform, characterized in that... The process involves depositing an inner cladding and a core layer. Using a quartz liner, a multilayer inner cladding and a multilayer core layer are deposited inside the liner via PCVD. The multilayer core layer consists of 2 to 4 layers, with the relative refractive index difference decreasing progressively from 0.2% to 0.7%. The core diameter ranges from 4 to 10 mm. The quartz liner is a doped quartz glass tube with a wall thickness of 6 to 9 mm. Its relative refractive index difference exhibits a gradual distribution, higher on the inside and lower on the outside, and is convex upwards. The relative refractive index difference on the inner surface of the liner is 0.1% to 0.2%, and on the outer surface it is -0.2% to 0%. The mandrel is fabricated by melting and shrinking the deposited tube, after the inner cladding and core layers have been deposited, into a mandrel containing both the core and inner cladding layers in a melting and shrinking lathe. The outer diameter and out-of-roundness of the mandrel are adjusted by controlling the axial movement speed and output power of the heating furnace during the melting and shrinking process. To fabricate an optical fiber preform, a pure silica cladding layer is deposited on the core rod using the OVD process, or a pure silica outer tube is fitted over the core rod. Through sintering or melting and shrinking treatment, a non-zero dispersion shift optical fiber preform is fabricated.

2. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 1, characterized in that... The heating and shrinking process involves adding rod diameter measuring instruments to both sides of the heating furnace on the shrinking lathe, and pressure sensors at both ends of the shrinking deposition tube. The deposition tube is installed on the lathe, and the heating furnace is moved while rotating. Through 2 to 6 shrinking passes, the rod diameter is gradually reduced while maintaining uniformity until a suitable and uniform center aperture is obtained in the aperture pass. The last pass is the solidification pass. During each shrinking pass, the change in rod diameter before and after shrinking is measured to form the axial distribution curve of the rod diameter for each pass. At the same time, the shrinking pressure is recorded and controlled to match the rod diameter. Then, the power and speed of the heating furnace are dynamically adjusted, and the pressure is controlled to effectively improve the out-of-roundness while avoiding gas line problems.

3. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 2, characterized in that... Based on the difference between the average value and the target value in the middle region of the deposition tube diameter, the heating furnace power of the subsequent melting and shrinking passes is adjusted. Based on the local changes in the tube diameter, the heating furnace speed at the corresponding position in the next pass is adjusted to ensure uniform melting and shrinkage of the tube diameter.

4. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 3, characterized in that... By matching the rod diameter and melting pressure, the roundness of the precast mandrel is improved.

5. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 2 or 3, characterized in that... The temperature of the heating furnace is controlled at 1600℃~2200℃, the speed of the heating furnace moving axially in the melting and shrinking furnace is 10~30mm / min, and the rotation speed of the deposition tube is 15~35 rad / min; the heating furnace is a graphite resistance heating furnace or induction furnace, the heating axial area is 100~350mm, and the circumferential gap between the heating furnace sleeve and the deposition tube is filled with protective gas.

6. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 2 or 3, characterized in that... The relative pressure of the melting and shrinking process is controlled within the range of ±30 Pa, and the relative pressure of the burning process is controlled within the range of -500 Pa to -990 Pa.

7. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 1 or 2, characterized in that... The outer cladding thickness of the optical fiber preform is 35~60mm.

8. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 1 or 2, characterized in that... The optical fiber preform core has three core layers: the first core layer has a relative refractive index difference Δn1 of 0.2-0.25% and a diameter of 7-9 mm; the second core layer has a relative refractive index difference Δn2 of 0.34-0.45% and a diameter of 5-7 mm; and the third core layer has a relative refractive index difference Δn3 of 0.5-0.6% and a diameter of 4-5 mm.

9. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 8, characterized in that... The optical fiber preform core has two inner cladding layers. The first inner cladding layer has a relative refractive index difference Δn4 of -0.1 to 0% and a diameter of 15 to 17 mm. The second inner cladding layer is composed of a quartz liner.

10. The method for manufacturing a non-zero dispersion-shifted single-mode optical fiber preform according to claim 1 or 2, characterized in that... The typical value of the core out-of-roundness of the optical fiber preform core is 0.4%.

11. A non-zero dispersion-shifted single-mode optical fiber preform, characterized in that... The non-zero dispersion-shifted single-mode fiber preform is manufactured according to the non-zero dispersion-shifted single-mode fiber preform manufacturing method according to any one of claims 1-10.

12. A non-zero dispersion-shifted single-mode optical fiber, characterized in that... The non-zero dispersion-shifted single-mode fiber described in claim 11 is formed by drawing the non-zero dispersion-shifted single-mode fiber preform.

13. The non-zero dispersion-shifted single-mode optical fiber according to claim 12, characterized in that... The optical fiber has an attenuation of ≤0.5dB / km at the 1383nm band, ≤0.195dB / km at the 1550nm band, and ≤0.200dB / km at the 1625nm band.

14. The non-zero dispersion-shifted single-mode optical fiber according to claim 12, characterized in that... The non-zero dispersion-shifted fiber has a dispersion slope ≤ 0.075 ps / Zero dispersion wavelength ≤1520nm, dispersion in the range of 1530nm~1565nm is 2~6ps / The dispersion in the 1565nm~1625nm range is 4.5~11.2ps / .

15. The non-zero dispersion-shifted single-mode optical fiber according to claim 12, characterized in that... The non-zero dispersion shifted fiber has a mode field diameter of 9.2μm-10μm at a wavelength of 1550nm, a cabling cutoff wavelength of ≤1450nm, and a bending loss of ≤0.03dB in a test of 100 turns with a diameter of 60mm.

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