Low-loss optical fibre

FIELD: physics, optics.

SUBSTANCE: invention relates to single-mode optical fibres having a low attenuation coefficient. The optical waveguide fibre includes a core and a cladding. The core includes an alpha-profile, where alpha (α) is greater than 2.5 and less than 3.0. The core and cladding provide the fibre with an attenuation coefficient of less than 0.331 dB/km at wavelength of 1310 nm, attenuation coefficient of less than 0.328 dB/km at wavelength of 1383 nm, attenuation coefficient of less than 0.270 dB/km at wavelength of 1410 nm and attenuation coefficient of less than 0.190 dB/km at wavelength of 1550 nm. Also provided is a method of producing the optical fibre.

EFFECT: reduced attenuation coefficient and bending loss.

5 cl, 8 dwg, 5 tbl

 

Cross-reference to related application

[0001] this application claims priority nepredvidatelne patent application U.S. No. 12/626305, filed November 25, 2009, entitled “Optical fiber with low loss”, the contents of which formed the basis of this application, and which is fully incorporated in the present description by reference.

The level of technology

[0002] the Disclosure relates, in General, to optical fibers and, in particular, to single-mode optical fibers having a low damping factor.

[0003] the Requirements in single-mode optical fiber suitable for use in a variety of applications and industry standard, for example, ITU-T G. 652, growing all the time. However, such properties of optical fibers, attenuation coefficient and the loss of the bend, contribute to the deterioration of the signal in such fibers. Therefore, great importance and commercial interest has a lower coefficient of attenuation and losses on the curve.

Disclosure of invention

[0004] One implementation includes an optical waveguide fiber that includes a core and a shell, wherein the core has a profile of the relative refractive index Δ(r), expressed in %. The core includes an alpha profile with an initial point r iand the endpoint of rfwhere alpha (α) greater than 2.5 and less than 3.0, the maximum relative refractive index Δ1MAXand outer radius R1. The core and the cladding provide a fiber with an attenuation factor of less than 0,331 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,328 dB/km at a wavelength of 1383 nm attenuation constant of less 0,270 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,190 dB/km at a wavelength of 1550 nm.

[0005] Another embodiment of the includes a method of manufacturing an optical fiber. The method includes pulling the fiber from a heated glass source. Furthermore, the method includes treating the optical fiber by maintaining the optical fiber in the treatment zone, while the optical fiber in the treatment zone is cooled at an average speed of less than 5,000°C/s. the Average cooling rate in the treatment zone is defined as the surface temperature of the fiber at the entrance to the treatment area minus the surface temperature of the fiber during exit from the treatment zone, divided by the total time of stay of the optical fiber in the treatment zone. The surface temperature of the optical fiber exiting the treatment zone is at least about 1,000°C. the Optical fiber has a core and a shell, and the core and the cladding about�guarantee the constant fiber with attenuation factor less 0,323 dB/km at a wavelength of 1310 nm, damping ratio less 0,310 dB/km at a wavelength of 1383 nm attenuation constant of less is 0.260 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,184 dB/km at a wavelength of 1550 nm.

[0006] Further features and advantages will be set forth in the following detailed description of the invention and, in particular, will be obvious to experts in the art from this description or understood in the practical application of the embodiments described in this document, including the following detailed description, the claims, and accompanying drawings.

[0007] it Should be understood that the foregoing General description and the following detailed description are illustrative implementation options and are designed to provide a General idea or a General scheme for understanding the nature and character of the claims. Accompanying drawings are included to provide further understanding and embedded in this description of the invention and constitute a part of him. The drawings illustrate various embodiments of and together with the description serve to explain the principles and operations of various embodiments.

Brief description of the drawings

[0008] Fig.1 schematically illustrates an embodiment of the optical waveguide fiber.

[0009] Fig.2 illustration�by the index profile of an illustrative embodiment of an optical waveguide fiber.

[0010] Fig.3 illustrates the profile of the refractive index additional illustrative embodiments of optical waveguide fibers.

[0011] Fig.4 illustrates a schematic side view in section of the device for forming optical fiber.

[0012] Fig.5 illustrates a schematic side view in section of an alternative device for forming optical fiber.

[0013] Fig.6 illustrates a system for making optical fibres.

[0014] Fig.7 illustrates a view in the analysis of the hydrodynamic bearing for use in the manufacture of optical fibers.

[0015] Fig.8 illustrates a planar side view of the hydrodynamic bearing having a cone-shaped area system for making optical fibres.

The implementation of the invention

[0016] Proceed to a detailed consideration of preferred embodiments, examples of which are illustrated in the attached drawings.

[0017] the Profile of the refractive index” means the ratio between the refractive index or the relative refractive index and the radius of the waveguide fiber.

[0018] the “Relative refractive index percent” is defined as Δ%=100×(ni2-nc2)/2ni2where ni- maximum refractive index in region i, unless otherwise naukasana return, and nc- the average refractive index of the outer region of the shell. Used here, the relative refractive index is denoted by Δ, and its value is expressed in “%”, unless specified otherwise.

[0019] “Chromatic dispersion”, called “dispersion”, unless otherwise specified, the waveguide fiber is the sum of the dispersion medium, the dispersion of the waveguide and Miodowa dispersion. In the case of a single-mode waveguide fibers Miodowa the variance is equal to zero. The dispersion slope of the curve is the rate of change of dispersion with respect to the wavelength.

[0020] an “Effective area” is defined as:

Aeff= 2π (∫f2r dr)2/(∫f4r dr),

where the integration is performed from 0 to ∞, and f is the transverse component of the electric field associated with the light propagating in the waveguide. As used herein, the term “effective area” or “Aeffmeans effective optical area at the wavelength of 1550 nm, unless otherwise specified.

[0021] the Term “α-profile” or “alpha profile” means a profile of the relative refractive index, denoted by Δ(r), expressed as “%”, where r is the radius according to the equation

Δ(r)=(Δ(ro)-Δ(r1))(1-[|r-ro|/(r1-ro)]α)+Δ(r1),

where ro- the point on the alpha profile, in which Δ(r) �maximalen, r1- the point on the alpha profile, in which Δ(r) is minimal, and r is enclosed in the range ri≤r≤rfwhere Δ is defined above, ri- the initial point of the α-profile, rf- the end point of the α-profile, and α is the exponent, a valid number.

[0022] the Diameter of the field of fashion (MFD) is measured using the Petermann II, where 2w=MFD, and w2=(2∫f2r dr/∫[df/dr]2r dr), the integration is performed from 0 to ∞.

[0023] the Resistance to bending of the waveguide fiber can be calibrated induced attenuation in a predefined test conditions, for example, unwinding or winding the fiber on a mandrel of predetermined diameter.

[0024] One type of bend test is a test of micro-deflection under lateral load. In this so-called test with “lateral load” predefined length of the waveguide fiber is placed between two flat plates. To one of the plates attached wire mesh #70. Known length of optical waveguide fiber is placed between the plates, and the reference attenuation coefficient is measured when the plates are pressed together with a force of 30 Newtons. Then attached to the plates force of 70 Newtons and measured the increase of the attenuation coefficient in dB/m. the increase in the coefficient of attenuation is the attenuation coefficient of the waveguide when �s load.

[0025] the bending Test on the pin matrix” is used to compare the relative stability of the optical waveguide fiber to bending. To implement this test measured loss for weakening waveguide fiber, substantially no induced losses in the bend. Then, the optical waveguide fiber is twisted round pin matrix and the damping factor is measured again. Losses induced by bending, are the difference between the two measured attenuation coefficients. Pin the matrix is a set of ten cylindrical pins placed in one row and held in a fixed vertical position on a flat surface. The distance between the pins is 5 mm, from center to center. The diameter of the pin is equal to 0.67 mm. during the test, insufficient tension to reconcile optical waveguide fiber with a portion of the surface of the pin.

[0026] theoretical wavelength cutoff fiber or “theoretical wavelength cutoff fiber” or “theoretical wavelength cutoff for the fashion, is the wave length, beyond which, canliterally light may not be distributed in this fashion. The mathematical definition is given in Single Mode Fiber Optics, Jeunhomme, pp. 39-44, Marcel Dekker, New York, 1990, where theoretical wavelength leads�Ki fiber described as wavelength, in which a constant distribution of fashion is equal to the propagation constant of a plane wave in the outer shell. This theoretical wavelength makes sense for an infinitely long perfectly straight fiber with no fluctuations diameter.

[0027] an Effective wavelength of a fiber cutoff of less theoretical wavelength cutoff due to losses induced by bending and/or mechanical pressure. In this context, the wavelength cutoff refers to a higher mode LP11 and LP02. LP11 and LP02, in General, cannot be distinguished by measurements, but they are observed both in the form of steps in the spectral dimension, i.e. no power is not observed in fashion at wavelengths greater than the measured wavelength cutoff. The actual wavelength cutoff of the fiber can be measured by standard tests on wavelength cutoff of 2 m fiber, FOTP-80 (EIA-TIA-455-80), to obtain the “wavelength cutoff fiber”, also known as “ wavelength cutoff of 2 m fiber” or “measured wavelength cutoff”. The standard test FOTP-80 is either to remove the mod of higher order using manageable the amount of Flex, or to normalize the spectral characteristics of fiber to the characteristics of the multimode fiber.

[0028] the wavelength cutoff in the cable or the wavelength of UTS�chki cable” more than the measured wavelength cutoff of the fiber due to higher levels of bending and mechanical pressure in the environment of the cable. Actual conditions in the cable can be approximated by testing per wavelength cutoff in the cable described in the testing procedures fiber optic EIA-445 (EIA-445 Fiber Optic Test Procedures, which form part of fiber optic standards EIA-TIA (EIA-TIA Fiber Optics Standards), that is, fiber-optic standards Alliance electronic industries - the telecommunications industry Association (Electronics Industry Alliance - the Telecommunications Industry Association Fiber Optics Standards), more commonly known as FOTP. The measurement wavelength cutoff in the cable described in EIA-455-170 "wavelength cable cutoff single-mode fiber by transmitted power" (Cable Cutoff Wavelength of Single-mode Fiber by Transmitted Power) or "FOTP-170".

[0029] If in the present description of the invention is not particularly stated otherwise, the optical properties (for example, dispersion, dispersion slope of the curve, etc.) are reported for fashion LP01. If in the present description of the invention is not particularly stated otherwise, the wavelength of 1550 nm is used as a reference wavelength.

[0030] In accordance with disclosed here options and implementation according to Fig.1 optical waveguide fiber 10 includes a core 12 and at least one sheath 14 surrounding the core 12. In a preferred var�the ants implementation, the shell 14 is made of pure quartz, and the core 12 is made of quartz doped with one or more additives. In a particularly preferred embodiment implementation, the core 12 is doped by a dopant which increases the refractive index, such as Ge, to obtain the desired change of the relative refractive index (for example, 3,5-4,2 molar % Ge). The core 12 may also be, optionally, doped with one or more additives that lower the refractive index, such as boron or fluorine. Preferably, the core diameter of 12 ranges from about 9 to about 16 microns. Preferably, the outside diameter of the shell 14 of optical fiber 10 is about 125 μm. Preferably, the area of the shell 14 has an outer radius of at least about 40 microns. As usual, the fiber may be covered with layers of polymer coatings 16 and 18.

[0031] the Core 12 of the optical waveguide fiber 10 passes in a radial direction outward from the center line to the radius R1and has a profile of the relative refractive index Δ(r), expressed in %, with a maximum percentage of relative refractive index Δ1MAX. R1is , by definition, is the radius at which Δ(r) first reaches of 0.02% when moving radially outwards from Δ1MAX.

[0032] the Profile of the indicator presale�settings (profile 1) illustrative embodiment disclosed here, the optical fiber shown in Fig.2, which shows the target profile 20 and the actual profile 22 of the core rod made in accordance with the target profile. Profile settings according to the embodiment of the shown in Fig.2, are shown in table 1.

Table 1
Target profileThe actual profile
Radius (µm)Delta (%)Radius (µm)Delta (%)
00,39000,325
to 0.2480,3900,2430,234
0,4960,3880,4880,385
1,0170,3811,0000,380
1,5130,3691,5120,380
2,0090,351 2,0000,356
2,5050,3262,5120,329
3,0010,2953,0000,296
3,5220,2543,5120,255
4,0180,2094,0000,209
4,5140,1564,5120,155
5,0100,0965,0000,094
5,5060,0295,5120,030
6,0020,0006,0000,014
7,0200,0007,0000,010
8,0120,0008,0000,006
9,0040,0009,0000,003
10,0200,00010,0000,001

[0033] the Simulated (predicted) performance parameters embodiment shown in Fig.2, are shown in table 2.

10,480
Table 2
PropertyProfile 1
The dispersion at the wavelength of 1310 nm (PS/(nm·km))-0,772
The slope of the curve of dispersion at the wavelength of 1310 nm (PS/(nm2·km))0,087
The diameter of the field of fashion (MFD) at a wavelength of 1310 nm (µm)9,200
The effective area (Aeff) at a wavelength of 1310 nm (μm2)64,600
The dispersion at the wavelength of 1550 nm (PS/(nm·km))16,610
The slope of the curve of dispersion at the wavelength of 1550 nm
(PS/(nm2·km))
0,056
The diameter of the field of fashion (MFD) at a wavelength of 1550 nm (µm)
The effective area (Aeff) at the wavelength of 1550 nm (μm2)82,330
LP11 wavelength cutoff (nm)1330,0
λ0(nm)1318,0
Dline wave cutoff cable (nm)1192,0
The attenuation coefficient at the wavelength of 1310 nm (dB/km)0,3301
The attenuation coefficient at the wavelength of 1383 nm (dB/km)0,3270
The attenuation coefficient at a wavelength of 1410 nm (dB/km)0,2687
The attenuation coefficient at the wavelength of 1550 nm (dB/km)0,1898
Loss microengine on the pin matrix at a wavelength of 1550 nm (dB)9,49
The loss of the micro-deflection under lateral load at the wavelength of 1550 nm (dB/m)0,64
Alpha (α)2,62

[0034] the Profiles of the refractive index additional illustrative embodiments disclosed here, the optical ox�con shown in Fig.3 24 (profile 2), 26 (3), 28 (profile 4) and 30 (profile 5). Profile settings according to the embodiment of the shown in Fig.3, are shown in table 3.

Table 3
Radius (µm)Profile 2 (Delta (%))Profile 3 (Delta (%))Profile 4 (Delta (%))Profile 5 (Delta (%))
00,3700,3600,363the 0.375
0,50,3700,3600,3630,374
1,00,3690,3580,3600,370
1,50,3670,3550,3550,361
2,00,3630,3500,3460,346
2,50,358 0,3420,3320,324
3,00,3510,3320,3130,293
3,50,3420,3180,2890,255
4,00,3300,3000,2570,202
4,50,0560,0510,0510,056
5,00,0460,0440,0440,047
5,50,0390,0380,0380,041
6,00,0340,0330,0330,035
6,50,0290,0280,0280.031 inch
7,00,0250,0240,0240,027
8,00,0170,0170,0170,020
9,00,0090,0090,0090,011
10,00,0050,0050,0050,007

[0035] the Simulated (predicted) performance parameters embodiment shown in Fig.3, are shown in table 4. The values of attenuation coefficient in table 4, represent the values of which, presumably, are achieved with the method of treatment, which includes passing the fiber through the treatment area as described in more detail below.

Table 4
PropertyProfile 2Profile 3Profile 4Profile 5
The dispersion at the wavelength of 1310 nm (PS/(nm·km))0,084-0,890-1,385-1,779
The slope of the curve of dispersion at the wavelength of 1310 nm (PS/( nm2·km))0,0870,0870,0870,088
The diameter of the field of fashion (MFD) at a wavelength of 1310 nm (µm)9,1869,1699,1859,214
The effective area (Aeff) at a wavelength of 1310 nm (μm2)66,03964,81464,40364,178
The dispersion at the wavelength of 1550 nm (PS/(nm·km))17,09916,08915,66515,453
The slope of the curve of dispersion at the wavelength of 1550 nm
(PS/( nm2·km))
0,0590,0590,0600,061
The diameter of the field of fashion (MFD) at a wavelength of 1550 nm (µm) 10,41510,53310,62110,702
The effective area (Aeff) at the wavelength of 1550 nm (μm2)82,66983,53784,36085,143
LP11 wavelength cutoff (nm)1434,41345,01311,01315,5
λ0(nm)1309,01320,21325,91330,2
Wavelength cable cutoff (nm)1294,41205,01171,01175,5
The attenuation coefficient at the wavelength of 1310 nm (dB/km)0,32650,32650,32530,3237

The attenuation coefficient at the wavelength of 1383 nm (dB/km)0,30240,30230,30120,2997
The attenuation coefficient at a wavelength of 1410 nm (dB/km)0,25850,25840,25740,2559
The attenuation coefficient at the wavelength of 1550 nm (dB/km)0,18600,18480,18380,1825
Loss microengine on the pin matrix at a wavelength of 1550 nm (dB)4,04910,54115,20916,751
The loss of the micro-deflection under lateral load at the wavelength of 1550 nm (dB/m)0,3480,7040,9411,078
Alpha (α)2,622,622,622,62

[0036] Disclosed here, the optical fibers have an alpha profile, where alpha (α) greater than 2.5, for example alpha, where alpha (α) greater than 2.5 and less than 3.0, and, by way of further example, the alpha-profile where alpha (α) greater than 2.5 and less of 2.7, and in the order of one additional example, the alpha-profile, DG� alpha (α) of more than 2.6 and less than 2,9, and, in another additional example, the alpha, where alpha (α) of more than 2.6 and less than a 2.7. Alpha values in these ranges can provide lower levels of decay than those that can be achieved in other ways.

[0037] Preferably, the starting point rithe alpha profile is at a radius of less than 1 μm, and the endpoint of rfthe alpha profile is at a radius of at least 3 μm, for example alpha profile, where the starting point rilocated on a radius of less than 0.5 μm, and the endpoint of rflocated on a radius of at least 4 μm, and, by way of further example, the alpha-profile, where the starting point rilocated on a radius of less than 0.25 μm, and the endpoint of rflocated on a radius of at least 5 μm. According to the embodiment of the shown in Fig.2, Δ(r) at rimore of 0.35%, and Δ(r) at rfless than 0.05%. According to embodiments of the implementation shown in Fig.3, Δ(r) at riis at least about 0.35%, and Δ(r) at rfis at least 0.20% and including at least 0.25 per cent, and further including at least 0,30%. According to embodiments of the implementation shown in Fig.3, Δ(r) at rf+0.5 microns, at least 0.10% less than Δ(r) at rffor example , at least 0.15% less than Δ(r) at rfand, in order differs�comparative example, at least 0.20% less than Δ(r) at rfand, in another additional example, at least 0.25% less than Δ(r) at rf. Preferred options for implementation consistent with those shown in Fig.3, include those in which alpha (α) greater than 2.5 and less than 3.0, riis from 0 to 0.5 µm, rfranges from 3.5 to 4.5 μm, Δ(r) at riis from 0.35% to 0.40%, Δ(r) at rfis from 0.20% to 0.33% and Δ(r) at rf+0.5 μm is from 0.02% to 0.10%.

[0038] Disclosed here, the optical fibers preferably have Δ1MAXmore than 0.30%, and also preferably have Δ1MAXless than 0.40%, for example 0,30%<Δ1MAX<0,40%, and, by way of further example, 0.35% to<Δ1MAX<0,40%, and in another additional example, 0,36%<Δ1MAX<0,39%.

[0039] Disclosed here, an optical fiber, preferably, R1from about 4 to about 12 μm, for example 5 μm <R1<10 μm, and, by way of further example, 6 μm <R1<8 μm.

[0040] Disclosed here, the optical fibers preferably have Δ(r), less than 0.01% for all radii larger than 10 μm, for example, Δ(r) less than 0.01% for all radii of more than 8 μm, and, by way of further example, Δ(r) less than 0.01% for all radii of more than 7 μm.

[0041] the Optical fiber, the appropriate implementation options, polluter�included in Fig.2 and 3, relatively simple in design and can meet the requirements of the industry standard in performance, which meets the optical fiber SMF-28®and SMF-28e®production Corning, at the same time, providing a more low attenuation and losses on the curve compared to these fibers.

[0042] for Example, disclosed here, the optical fiber including the procedures for the implementation illustrated in Fig.2 and 3, preferably, provide the diameter of the field of fashion at the wavelength of 1310 nm, from about 8.8 to about 9.6 microns and, more preferably, from about 9.0 to about 9.4 microns. Disclosed here, the optical fiber preferably provide the diameter of the field of fashion at the wavelength of 1550 nm, from about 9.8 to about of 11.0 μm and, more preferably, from about 10.0 to about 10.8 μm. Disclosed here, an optical fiber, preferably, provide the effective area at the wavelength of 1310 nm, from about 60 to about 70 μm2and, more preferably, from about 62 to about 68 μm2. Disclosed here, the optical fiber preferably provide the effective area at the wavelength of 1550 nm, from about 75 to about 90 μm2and, more preferably, from about 78 to about 86 μm2. Disclosed here, the optical fibers preferably have a wavelength of zero dispersion, λ0from about 1300 to about 1335 nm and, more preferably,from about 1302 to about 1322 nm. Disclosed here, the optical fibers preferably have a slope of zero dispersion less than or equal to about 0,089 PS/(nm2·km). Disclosed here, an optical fiber, preferably, have a dispersion at a wavelength of 1550 nm of less than 18,0 PS/(nm·km). Disclosed here, the optical fibers preferably have a critical wavelength of cable less than or equal to 1300 nm, for example, the critical wave length of the cable is less than or equal to 1260 nm, and, by way of further example, the critical wave length of the cable is less than or equal to 1220 nm, and in another additional example, the critical wave length of the cable is less than or equal to 1200 nm, and in another additional example, the critical wave length of the cable is less than or equal to 1180 nm.

[0043] Disclosed here, the optical fiber including the procedures for the implementation illustrated in Fig.2 and 3, have a damping ratio less 0,331 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,328 dB/km at a wavelength of 1383 nm attenuation coefficient less 0,270 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,190 dB/km at a wavelength of 1550 nm.

[0044] In preferred embodiments, as disclosed here, the optical fiber has an attenuation coefficient of less than 0,325 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,323 dB/km at a wavelength of 1383 n�, the damping factor is less 0,264 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,186 dB/km at a wavelength of 1550 nm.

[0045] In even more preferred embodiments disclosed here, the optical fiber has an attenuation coefficient of less than 0,324 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,322 dB/km at a wavelength of 1383 nm attenuation coefficient less to 0.263 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,185 dB/km at a wavelength of 1550 nm.

[0046] In even more preferred embodiments disclosed here, the optical fiber has an attenuation coefficient of less than 0,323 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,310 dB/km at a wavelength of 1383 nm attenuation coefficient less is 0.260 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,184 dB/km at a wavelength of 1550 nm.

[0047] In even more preferred embodiments disclosed here, the optical fiber has an attenuation coefficient of less than 0,323 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,300 dB/km at a wavelength of 1383 nm attenuation coefficient less 0,255 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,182 dB/km at a wavelength of 1550 nm.

[0048] In further preferred embodiments disclosed here, the optical fiber has an attenuation coefficient of less than 0,327 dB/km at a wavelength of 1310 nm, kOe�of ficient less attenuation to 0.303 dB/km at a wavelength of 1383 nm, the damping factor is less 0,259 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,187 dB/km at a wavelength of 1550 nm.

[0049] In further preferred embodiments disclosed here, the optical fiber has an attenuation coefficient of less than 0,327 dB/km at a wavelength of 1310 nm, an attenuation factor less to 0.303 dB/km at a wavelength of 1383 nm attenuation coefficient less 0,259 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,185 dB/km at a wavelength of 1550 nm.

[0050] In other further preferred embodiments, as disclosed here, the optical fiber has an attenuation coefficient of less than 0,326 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,302 dB/km at a wavelength of 1383 nm attenuation coefficient less 0,258 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,184 dB/km at a wavelength of 1550 nm.

[0051] In other further preferred embodiments, as disclosed here, the optical fiber has an attenuation coefficient of less than 0,324 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,300 dB/km at a wavelength of 1383 nm attenuation coefficient less 0,256 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,183 dB/km at a wavelength of 1550 nm.

[0052] Disclosed here, the optical fibers preferably have a loss on microengine pin on the matrix of less than 10 dB at a wavelength of 1550 n�, and even more preferably less than 9.5 dB at the wavelength of 1550 nm, even more preferably less than 9 dB at the wavelength of 1550 nm.

[0053] Disclosed here, the optical fibers preferably have a loss on the micro-deflection under lateral load is less than 0.7 dB/m at a wavelength of 1550 nm, and even more preferably less than 0.65 dB/m at a wavelength of 1550 nm, and even more preferably less than 0.6 dB/m at a wavelength of 1550 nm.

[0054] In preferred embodiments disclosed here, the optical fibers are made by passing the fibers through the treatment area, which is defined as the area located after strand furnace, where the fiber is cooled at a speed that is lower than the cooling rate of the fiber in air at room temperature (i.e. in air at a temperature of about 25°C). Preferably, the surface temperature of the fiber exiting the treatment zone is at least about 1,000°C.

[0055] the Average cooling rate of the fiber in the treatment zone is defined as the surface temperature of the fiber at the entry point of the fiber in the treatment zone (temperature at the input surface of the fiber) minus the temperature of the surface of the fiber at the fiber treatment zone (the temperature at the output surface of the fiber), divided by the total time of stay fiber in the treatment zone. In a preferred embodiment the OSU�of estline, the average cooling rate of the fiber in the treatment zone is less than 5,000°C/s, including less than 2,500°C/s, and including, additionally, less than 1,000°C/s, when the temperature of the fiber is at least 1,000°C, for example, when the temperature of the fiber ranges from 1,250°C to 1,750°C.

[0056] In at least one embodiment of the implementation, the treatment area contains treatment furnace. In one embodiment, implementation, treatment furnace is essentially immediately after strand furnace, although the invention is not limited to implementation options, where treatment furnace is essentially immediately after strand furnace. In a preferred embodiment implementation, treatment furnace attached directly to the end of the strand furnace in a location where the fiber comes out of it, making between them, preferably, formed a tight connection. This minimizes unwanted air flow lingering in the oven.

[0057] Fig.4 illustrates the device 300 of forming an optical fiber that can be used in the manufacture disclosed here optical fiber. The device 300 includes, in General, lingering furnace 112, oven 350 processing and installation 128 tension, the tractor is shown as a node for the application of tension to the elongated fiber. The device 300 can be used to handle naked in optical�the lament 10, for example, of stainless glass workpiece 110. More specifically, lingering furnace 112 can be used for the formation of a naked optical fiber 10, and then oven 350 processing can be used for the treatment of an elongated fiber 10. The tension setting of 128 is used to control and maintain the desired tension in the fiber 10. May include additional conventional stages of the process, such as a device for the contactless measurement of the diameter, the additional cooling device fiber device coating and curing of the fiber for application and curing of the primary and secondary coatings fiber, and winding on a bobbin. Such additional process steps are traditional and for clarity is not shown. Additionally, at the bottom of the furnace treatment can be applied mechanism, an iris diaphragm or movable doors to minimize air flow into the furnace processing.

[0058] a Glass preform 110 is preferably formed from doped quartz glass, and preferably of quartz glass doped, at least, Germany. Methods and apparatus for forming the workpiece 110 is well known and obvious to those skilled in the art. Such methods include IVD, VAD, MCVD, OVD, PCVD, etc.

[0059] Lingering furnace 112 preferably includes a housing 322, environment�th the workpiece and having a flange 323, fixed on its lower end, and a flange 323 acts as the output strand furnace wall 112. In the flange 323 is provided an axial hole 324, through which the fiber 10 and through which can pass the previously elongated piece of glass. Annular tubular holder 326 (which may be made of, for example, graphite) passes through the lingering furnace 112 and forms in the passage 330. The passage 330 includes a top section, intended for reception and retention of the workpiece 110 of the optical fiber, and a lower section, through which the elongated fiber 10 passes and melting and pulling the glass from the workpiece 110. The piece, formed at the beginning of stretching, also passes through this section. The lower section of the passage 330 communicates with the opening 324. Hollow output cone 339, preferably, is positioned over the hole 324. The annular insulator 332 and the coil(s) 336 inductance surround the holder 326.

[0060] a Suitable inert gas FG formation, such as helium, can be pumped into the passage 330 under a pressure of about 1 atmosphere through a suitable inlet port 338, whereby it will flow down and out of the strand furnace 112 through the opening 324. Described and illustrated lingering furnace 112 is merely illustrative of suitable plangent furnaces, and specialists in the art should be �obvious, what you can apply broaching other furnace designs and configurations, for example, using other types of heating mechanisms, holders and insulation, etc.

[0061] Again, according to Fig.4, the opposite flow passages 348 pass radially through the flange 323 and end with holes on its upper surface 323A. The passages 348 also extend vertically through the flange 323 and end near the outer perimeter of the cone 339. Gas FG formation is additionally fed through the openings of the passages 348 and flows up around the cone 339 and comes back down through the center hole of the cone 339. Gas FG formation may be, for example, helium gas (He), gaseous nitrogen (N2), argon (Ar) or any other suitable inert gas.

[0062] Oven 350 processing is located under the flange 323 and, preferably, connected with him. Oven 350 processing includes block 360 heating with one or more annular heating elements 368 in it. The heating element may be, for example, electrical resistance heating or induction coil. Openings 352A and 354A is provided on the upper and lower ends of the furnace 352 and 354 of treatment, respectively. Holes along the way pulling big enough piece of glass could fall through them last� start pulling. The ends 352, 354 and pipe 346 act as housing for oven 350 processing. However, it is clear that it is possible to use other configurations and components of the housing. Oven 350 processing is preferably attached to the flange 323 strand furnace 112 by suitable means, such as by fasteners.

[0063] In block 360 of heating is, in General, a cylindrical bobbin or tube 362. Bobbin or tube 362, which may be made of essentially pure quartz glass, ceramic and/or carbon material, forms a passage 362A and has a pair of flanges (i.e. quartz flanges) 362B, located at its opposite ends. Flanges 362B may be, for example, welded by gas welding to the ends of the tube for forming a bobbin 362. First graphite packing 364 laid between the lower surface of the flange 352 and the upper flange 362B. Second graphite packing 364 laid between the lower flange 354 and lower flange 362B.

[0064] a Gas ring 366 having inlet passages 366A, surrounded by graphite seals 364 and have small perforations designed to direct the flushing gas to PG graphite gaskets 364. The purge gas PG can reduce or prevent exposure to air on the graphite seals 364 and may be, for example, helium (He), argon (Ar), nitrogen (N2) or any other suitable inert �AZ.

[0065] Detail 359 flushing gas is attached to the lower surface of the flange 354. The purge gas PG is injected into the passage 359A flushing tube to prevent the ingress of air into the passage 362A from below.

[0066] the Passage 362A tube 362 preferably has a diameter D of more than 12 mm along its entire length and, preferably, from about 12 mm to about 80 mm and, more preferably, from 45 mm to 80 mm, so that the piece of glass, formed at the beginning of the pull, was free to fall through it.

[0067] the tension Setting of 128 may be any suitable device for adjusting the tension in a stretched fiber 10. Preferably, the tension setting of 128 includes a microprocessor which continuously receives input from one or more sensors for tension and/or diameter of the fiber (not shown) and is able, if necessary, to inform the tension of the fiber 10. In a preferred embodiment of the prescribed tension adjustment is based on the diameter to a predetermined diameter that is stored in memory.

[0068] the Device 300 can be used as follows to obtain a treated optical fiber 10. Coil 336 inductance furnace is used to heat the thin end 302A of the workpiece 110 of the optical fiber to a pre-selected temperature extrusion TD. Preferably, the temperature in�of taiwania T Dis in the range of about 1,800°C to about 2,200°C. More preferably, the stretching temperature TDis in the range from about 1,900°C to about 2,050°C. the Thin end 302A of the workpiece is maintained at the selected temperature extrusion TD, making a stretched fiber 10 is continuously extruded from the thin end 302A in the direction V of the drawing, i.e. preferably vertically downward. The fiber 10 is supported above the calculated tension FDstretching stretching device 370 or other suitable device to create tension to align with the specified diameter (typically 125 microns) fiber in a predetermined tolerance range. Gas FG formation (e.g. helium) is injected from the upper inlet channel through the passages 338 330, 324, 352A, 362A, 354A and exits through the passage 359A flushing tube.

[0069] Since the fixture 350 processing, preferably, installed, essentially, directly next to the hole 324 strand furnace 112, stretched fiber 10 is preferably not quenched colder ambient air at the exit of the fiber strand furnace 10 of 112. Additionally, it reduces the possibility of oxygen lingering in the furnace, thereby minimizing the possible deterioration of the graphite holder 326. Bare optical fiber 10 passes through the passage 32 and, essentially, immediately heated block 360 heating. Block 360 heat maintains the temperature of the fiber 10 is equal to the temperature TTprocessing in a selected temperature range of T1up to T2. Lower temperature T1preferably, ranges from about 1,100°C to about 1,400°C and higher temperature T2preferably, ranges from about 1,200°C to about 1,800°C. More preferably, the lower temperature T1is from about 1,150°C to about 1,350°C and higher temperature T2is from about 1,300°C to about 1,700°C. in addition, when the fiber 10 passes through the passage 362A, the fiber 10 is maintained at the desired tension FTthe processing. Preferably, the tension FTtreatment is from about 25 to about 200 grams. More preferably, the tension FTtreatment is from about 75 to about 175 grams. The length L of the treatment area is selected so that a stretched fiber 10 is maintained within a selected temperature range of T1up to T2during the selected time tTstay at processing conditions. The treated fiber 10 exits the oven to 350 processing through the lower hole 354A and preferably comes to additional processing units (additional cooling, dimensions, coatings, etc.).

[0070] Preferably, protag�th furnace 112 and bake 350 processing configured and installed relative to each other, and gases are injected so as to provide air-tight path from the passage 330 to the hole 359A.

[0071] In a preferred embodiment of the oven of 350 processing includes a plurality of individual heaters spaced along the axial length of the furnace 350 processing. Each heater surrounds the fiber, and each is preferably individually controlled by the controller. On the stage of heat treatment, the fiber is heated from multiple heating zones; at least one of the heating zones (each zone roughly corresponds to the physical size of the heaters) multiple heating zones set at a different temperature compared to other of the multiple heating zones. Preferably, the wall temperature of each heater is controlled by the controller so that at least one of the heating zones had a temperature of passage from 600°C to 1,500°C. In a preferred mode of operation, the first area that was closest to the strand furnace 112 is adjusted so that the temperature of the passage in its center ranged from 600°C to 1,200°C, while the second zone is more remote from strand furnace is adjusted so that the temperature of the passage ranged from 900°C to 1,500°C. the Actual temperature of the walls will be installed so that to achieve the desired temperature conditions on the output surface of the fiber to achieve the desired IC�grow cooling. In the case of gas except helium, for example, the wall temperature will be set to a lower temperature, since the argon and mixtures of argon and helium have a lower coefficient of thermal conductivity, and therefore, to achieve the same cooling rate will require a more significant temperature difference between the temperature of the passage of the kiln and the temperature of the fiber.

[0072] In at least one preferred embodiment of the heating elements of the furnace 350 processing, preferably, are politicalizing high temperature heating elements, available from Kanthal.

[0073] In at least another embodiment of the implementation, the treatment area contains the passive node processing. In one embodiment of the implementation, the passive node processing is essentially immediately after strand furnace, although the invention is not limited to variations on the implementation, the passive node processing is essentially immediately after strand furnace. In a preferred embodiment implementation, the passive processing node directly connected to the end of the strand furnace in a location where the fiber comes out of it, so that, between them, preferably, formed a tight connection. This minimizes unwanted air flow lingering in the oven.

[0074] Fig.5 illustrates al�ernative device 400 of forming an optical fiber, which can be used in the manufacture disclosed here optical fiber. The device 400 of forming an optical fiber includes lingering furnace 112, corresponding strand furnace 112. Instead of the oven 350 processing device 400 includes a node 450 passive processing. Node 450 is “passive” in the sense that it does not include a heating device appropriate heating module 360, none of the site. In other words, the fiber is cooled variable speed without the help of active heating module.

[0075] the Device 400 includes a lingering furnace 112 and 128 installation tension corresponding strand furnace 112 and 128 installation tension, respectively. Preferably, talkin furnace 112 is of the type providing for the presence of the graphite holder. Node 450 passive treatment includes a tubular muffle 452 having an upper flange 454. Muffle 452 attached directly to the lower end wall 423 of the furnace 112 by bolts or other fasteners (for simplicity not shown) that pass through holes in the flange 454 and engages with the front wall 423. Muffle 452, preferably made of metal, such as stainless steel or aluminum.

[0076] the Muffle 452 forms a top opening 456 at a first end, an oppositely� the lower hole 458 at the second end and a passage 452A, leading between them. Preferably, the diameter E of the passage 452A essentially homogeneous and is more than 12 mm, more preferably, from about 12 mm to about 80 mm, and most preferably from 45 to 80 mm. Top hole 456 communicates with the bottom hole 424 strand furnace 112. In the side wall of the muffle 452 formed on the set spaced along the axis of the input channels 459, communicating with the passage 452A throughout its length.

[0077] the System 460 processing gas flows quickly and hydraulically connected to the muffle 452. System 460 gas flows of processing includes the installation 461 gas processing, and hydraulically operatively connected to each of the channels 459 manifold or conduit 462. Installation 461 gas processing includes a source gas selected TG treatment, and pump, etc., capable of pumping gas TG treatment rather strongly for its passage through conduit 462 input channels and 459 in the passage 452A. Installation 461 gas processing may, optionally, include a heating unit for heating the gas TG treatment. However, it is preferable to supply gas treatment at a temperature of about 20°C.

[0078] the Device 400 can be used to form a treated optical fiber 10 as follows. Using strand furnace 112 and install 128 optic tension volokno is extracted from the workpiece 110, as described above in relation to device 300, when the stretching temperature and the stretching stretching enough for making defect thermal aging. When pulling fiber 10, the gas FG formation is introduced through the inlet channel shown in Fig.4. Gas formation flows through the passage 430 around the workpiece 110 and the fiber 10, through hole 424 in the end wall 423 kiln and the first end of the passage 452A through hole 456.

[0079] a Stretched fiber 10 is included in the passage 452A muffle 452 immediately at the outlet of the furnace 112. While fiber 10 passes through the passage 452A, gas TG treatment is pumped from the unit 461 gas flow of processing in the passage 452A through at least two spaced-axis input channel 459, indicated by arrows in Fig.5. Gas processing flows into the passage 452A at various stages and mixes with the gas FG formation. Preferably, the TG gas processing has a thermal conductivity k of less than about 120×10-6cal/(s) (cm)2(°C/cm) and, more preferably, less than about 65×10-6cal/(s) (cm)2(°C/cm) at 25°C. the TG of the Mixture of gas processing and gas FG formation flows through the passage 452A and exits through the hole of the second end 458.

[0080] the TG Gas processing has a lower conductivity than the gas FG formation. Preferably, thermal conductivity of the gas TG treatment is less than 40% and, more preferably, less than 20% of thermal conductivity of the gas FG formation. The TG gas processing preferably represents nitrogen or argon, but may also include krypton or xenon.

[0081] When extruding an elongated fiber 10 through the passage 452A, stretched fiber 10 is maintained at the desired tension FTprocessing, and temperature TTprocessing fiber 10 while it is in the passage 452A, is maintained within a selected temperature range T1-T2during the selected time tTstay, as discussed above in connection with the device 300. As described above in relation to device 300, the selected tension FTthe processing temperature range of T1up to T2and time tTstay jointly chosen to reduce or eliminate heat aging defect in the fiber 10 and, thus, provide processed bare optical fiber 10. In the case of the device 400, the length M of passage 452A fixture 450 passive treatment is selected to provide the desired time tTstay in accordance with the speed of extrusion of the fiber 10.

[0082] the lower thermal conductivity of the gas TG treatment slows the transfer of heat from the extruded fiber 10 or cooling, whereby the fiber 10 is supported in a selected temperature range T1-T2while in the passage 452A. Flow, turbulence and temperature�the TG gas processing, you can choose accordingly to provide the desired cooling rate. In accordance with this embodiment of the invention, the desired cooling rate in the treatment zone may range from 1,000°C/s up to 3,500°C/s in the temperature range of from 1,200°C to 1,500°C.

[0083] In a particularly preferred embodiment implementation, talkin furnace area 112 and 130 processing (which may contain, for example, the oven 350 processing according to Fig.4 or node 450 passive processing according to Fig.5) included in the system 108 for manufacturing optical fibers according to Fig.6. After the optical fiber 10 is leaving the area 130 of the processing, the optical fiber is in contact, at least one stationary hydrodynamic bearing 116 (shown in Fig.6 in the form of a plurality of hydrodynamic bearings) and proceeds from moving along essentially the first or vertical path (Y) on the second path (Z). As shown, the second path (Z) is horizontal and orthogonal to the first way, but it should be understood that the described system and methods allow to redirect the optical fiber according to any nonlinear path to applying the protective coating.

[0084] According to the embodiment of the shown in Fig.6, the optical fiber 10 passes through hydrodynamic bearings 116 and is supplied to the block 120 of the coating, where the primary layer 121 of the protective coating is applied to the external surface�th optical fiber 10. After leaving the block 120 the coating of the optical fiber with a protective layer 121 (not naked) may pass through various other stages of processing in the system (not shown). Mechanisms 128 stretching are used to provide the necessary tension of the optical fiber by " pulling throughout the system, as shown in Fig.6, and the final winding on a bobbin to hold the fiber (not shown).

[0085] When transporting the optical fiber 10 according to the hydrodynamic bearings 116 (described below) the area of the hydraulic cushion at each hydrodynamic bearing 116 cools the optical fiber 10. For example, according to Fig.6, the optical fiber 10 extending from the zone 130 processing, may have a temperature of about 500°C to 1500°C at the entrance to the hydrodynamic bearings 116. In some preferred embodiments, the optical fiber 10 is included in hydrodynamic bearings 116 at the point where the temperature of the fiber is less than 1,300°C, more preferably, less than 1,200°C, and in some embodiments less than 1,100°C. As in the hydrodynamic bearing is used the flow of a fluid medium, which supports the optical fiber, the optical fiber is cooled with a much greater speed than it was cooled'd still air at room temperature, which, for�p, is present directly at the exit of the strand furnace. The greater the temperature difference between the optical fiber and the fluid in the hydrodynamic bearing (which preferably is air at room temperature), the greater the ability of the hydrodynamic bearing to cool the optical fiber 10. In another embodiment of the implementation, the fluid produced through hydrodynamic bearings 116, may actually be cooled to cool the optical fiber with even greater speed. Fluid relating to hydraulic cushion, can provide sufficient cooling of the optical fiber 10 to transport it directly to the block 120 coating, and a protective layer can be applied on the external surface of the optical fiber 10 to create a coated fiber 121. In one embodiment of the implementation, the area of the hydraulic cushion hydrodynamic bearing 116 may include a fluid medium inert to the optical fiber 10 (for example, air, helium).

[0086] Fig.7 illustrates the embodiment of the bearing Assembly 216, which can be used as described herein in the manufacture of optical fiber. According to the embodiment of the shown in Fig.7, the bearing Assembly 216 (sometimes referred to as the hydrodynamic bearings�") includes a first plate 230, a second plate 232, 236 internal detail and at least one hole 234 in at least one of the first and second plates. The first plate 230 and the second plate 232 can be made of metal and may include an arcuate outer surface 238, 239 and can be placed opposite each other. The first plate 230 and the second plate 232 is connected by fasteners (such as bolts 240), connecting plates 230, 232 each other so that fluid can pass through the bearing Assembly 216. An arcuate outer surface 238, 239 each plate 230, 232, in General, rely on the perimeter of each of the respective plates 230, 232. The first plate 230 and the second plate 232 have respective inner 242, 244 and outer side 243, 245, with inner sides 242, 244 of the plates 230, 232 are aligned with each other. An in-depth plot 247 passes at least partially around an interior sides 242, 244 of the first plate 230 or the second plate 232 for providing a cavity for fluid flow. In another embodiment of the implementation, in-depth site may contain various configurations to provide a uniform flow in the channel support 250 fiber, discussed below.

[0087] According to the illustrated embodiment of the, an arcuate outer surface 238, 239 of the first plate 230 and second� plate 232, preferably, essentially aligned and form a region between the outer surfaces 238, 239 of the first plate 230 and the second plate 232. This area is used for receiving the optical fiber, the optical fiber could be moved along this area without rotation of the bearing arrangement. This channel 250 fiber support is more clearly illustrated according to the embodiment of the shown in Fig.8 (discussed below). At least one hole 234 passes through at least one of the first plate 230 and the second plate 232. According Fig.7, the opening 234 of the first plate 230 and the second plate 232 to supply the fluid medium (such as air, helium or other gas or liquid if desired) through the bearing Assembly 216, so that fluid could leave the bearing unit 216 through the channel support 250 fiber formed between the first plate 230 and the second plate 232.

[0088] additionally, as shown according to the embodiment of the Fig.7, the bearing Assembly 216 may include an internal detail 236 located between the first plate 230 and the second plate 232. This internal detail 236 (for example, the gasket 237) is intended to help direct the fluid into the region between the outer surfaces 238, 239 of the first plate 230 and the second plate 232 so that fluid was coming out of the channel TII fiber, having a predetermined direction of flow. The internal part 236 is located between the first plate 230 and the second plate 232 to provide a gap therebetween. Internal detail 236 directs the fluid to come out of the channel support 250 fiber having a predetermined direction of flow. If desired, the inner part 236 may comprise a plurality of prongs (not shown) to control the flow of fluid through the counter neradilek. In addition, the internal detail 236 acts as a sealing area to ensure substantial contact between the first plate 230 and the second plate 232. Internal detail can also include grooves that facilitate the input and output optical fibers.

[0089] According to Fig.8, the channel support 250 fiber formed between the outer surfaces 238, 239 of the first plate 230 and the second plate 232 may have a conical shape where the output of the fluid between the first plate 230 and the second plate 232. However, in another embodiment of the implementation, the channel support 250 fiber may include, for example, parallel or inverted conical shape. In addition, a hole 260 in the tapered channel support 250 fiber has the ability to change depending on the vertical position of the optical�technical fiber 10. Preferably, the hole 260 and the channel support 250 fibers are configured such that for a particular applied tension pulling and pulling speeds and flow rates of the fluid through the opening 260 of the optical fiber is supported in the section of the channel support 250 fiber, the width of which is less than 500, more preferably less than 400, preferably less than 300, and most preferably less than 200 microns, for a fiber having a typical outer diameter of 125 microns. Thus, the fiber is preferably retained in the channel region of 250, which is 1 to 2 times the diameter of the fiber, more preferably, from 1 to 1.75 times the diameter of the fibers and, most preferably, from 1 to 1.5 times the diameter of the fiber. Preferably, the fiber is arranged on the channel, so that the distance between the outer fiber and each wall is from 0.05 to 0.5 of the diameter of the fiber.

[0090] Described herein hydrodynamic bearings allow the optical fiber to move along the field hydraulic cushion, preventing or substantially preventing the actual mechanical contact between the optical fiber and the bearing unit, such as the fiber is moved in the channel 250 fiber support, no contact with any of the plates 230 or 232. Furthermore, due to the size and configuration region�STI, the hydrodynamic bearing is capable of supporting the fiber in the field without mechanical contact throughout the range of the pulling tension in the absence of active management of the flow of fluid. According Fig.8, the fluid flow can play an important role in preventing the displacement of the optical fiber 10 to the lower end of the channel support 250 fiber and coming into contact with the gasket 237 or sides of the channel support 250 fibers. This is particularly important when the optical fiber is still exposed to the quality of the fiber is not damaged due to mechanical contact with the bearing unit.

[0091] Other factors affecting the position of the fiber channel support 250 fibers comprise a pulling tension. For example, fiber, adjusting the tension of 200 g, will swim in the channel support 250 fiber is lower than the fiber is extended by tension of 100 g at the same flow rate of the fluid. In this regard, it is important that from the field of hydrodynamic bearing came out a sufficient amount of fluid to maintain the optical fiber in the desired position applied for a specific speed of the stretching and pulling of fiber drawing.

[0092] the hydrodynamic Radius of the bearings 116 does not play a decisive role. In some embodiments, the design of each hydrodynamic�die bearing ensures bend radius of the fibers from about 8 to about 16 cm. You can apply the hydrodynamic bearings of larger or smaller radius, or you can apply additional hydrodynamic bearings (for example, shown in Fig.1), for example, depending on, preferably for cooling (in which case, you can give preference to the hydrodynamic bearing larger radius) or depending on the limitations of the process of fiber drawing.

[0093] In preferred embodiments, the optical fiber is extruded at a speed of pulling greater than or equal to 15 m/s, preferably greater than or equal to 25 m/s and even more preferably greater than or equal to 35 m/s, followed by heat treatment of the optical fiber by maintaining the optical fiber in the treatment zone, while the optical fiber in the treatment zone is cooled at an average speed of less than 5,000°C/s, for example with an average speed of cooling from 500°C/s to 5,000°C/s, including the average cooling rate from 500°C/s up to 2,500°C/s, and further including average cooling rate of 500°C/s to 1,000°C/s.

[0094] According to the embodiment of the shown in Fig.6, the length of the zone 130 treatment preferably ranges from about 2 m to about 10 m and, more preferably, from about 3 m to about 8 m, for example from about 4 m to about 6 m. the Preferred length�and will depend on the speed of extrusion of the fiber 10, and examples of ranges of speed pulling range from about 5 m/s to about 45 m/s, for example, from about 10 m/s to about 35 m/s, including from about 15 m/s to about 25 m/s. the Presence of hydrodynamic bearings 116 (as shown in Fig.6) after 130 allows the treatment to ensure a longer area 130 processing. Longer oven 350 processing, in turn, allows you to create the optical fiber with low attenuation coefficient.

[0095] In preferred embodiments, the residence time of the optical fiber 10 in the zone 130 processing time is from 0.05 to 0.50 seconds seconds, for example from 0.10 to 0.35 seconds seconds and, by way of further example, from 0.15 seconds to 0.25 seconds.

[0096] the methods Described herein, providing for transmission of the optical fiber through the treatment area, may include the active node of heating shown in Fig.4, or the node is passive heating, shown in Fig.5, and the node is active or passive heating can be used independently or together with the bearing unit according to Fig.6. Following the here described processing steps, you can also use additional processing steps, such as standard treatment with deuterium using methods known in the art.

[0097] the Disclosed here implementation options are explained further in the following example.

EXAMPLE 1

[0098] Was made about 430 km of optical fiber�and, having the index profile corresponding to the profile shown in Fig.2. Optical fibers were manufactured using the device for forming optical fiber, similar to that shown in Fig.4, in which treatment furnace was located after strand furnace, the heat treatment furnace area had a length of about 1.5 m and the set value of the wall temperature was about 600°C. the Fiber is pulled at a pulling speed of about 14 m/s in tension pulling about 150 grams. The measured performance parameters for optical fibers are shown in table 5. As shown in table 5, the measured values of attenuation coefficient is lower than the simulated (predicted) values, given in table 2.

Table 5
The average valueThe intermediate valueThe minimum valueThe maximum value
The diameter of the field of fashion (MFD) at a wavelength of 1310 nm (µm)9,1849,1769,1439,243
λ0 1318,7681318,7261317,9461320,095
Wavelength cable cutoff (nm)1196,8611198,8991166,0431237,194
The attenuation coefficient at the wavelength of 1310 nm (dB/km)0,3220,3220,3200,323
The attenuation coefficient at the wavelength of 1383 nm (dB/km)0,2980,2970,2850,321
The attenuation coefficient at a wavelength of 1410 nm (dB/km)0,2550,2540,2510,262
The attenuation coefficient at the wavelength of 1550 nm (dB/km)0,1830,1830,1820,184

[0099] the Specialists in the art can offer a variety of modifications and changes without departing from the scope of the essence and scope of the invention.

1. Optical waveguide fiber containing
iand the endpoint of rfwhere alpha (α) greater than 2.5 and less than 3.0, the maximum relative refractive index Δ1MAXand outer radius R1
and the core and the cladding provide a fiber with an attenuation factor of less than 0,331 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,328 dB/km at a wavelength of 1383 nm attenuation constant of less 0,270 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,190 dB/km at a wavelength of 1550 nm.

2. The optical waveguide fiber according to claim 1, wherein 0,30% < Δ1MAX< 0,40%.

3. The optical waveguide fiber according to claim 1, wherein the core and the cladding provide a fiber with an attenuation factor of less than 0,325 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,323 dB/km at a wavelength of 1383 nm attenuation constant of less 0,264 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,186 dB/km at a wavelength of 1550 nm.

4. The optical waveguide fiber according to claim 1, in which 2,6 < alpha (α) < 2,9.

5. A method of manufacturing an optical fiber, the method includes the steps in which
pull the fiber from a heated glass source and
groomed optical fiber by spon�Jania optical fiber in the treatment zone, while the optical fiber in the treatment zone is subjected to cooling at a moderate speed, defined as the temperature at the input surface of the fiber minus the temperature at the output surface of the fiber divided by the total time of stay of the optical fiber in the treatment zone is less than 5000°C/s, and the surface temperature of the optical fiber exiting the treatment zone is at least about 1000°C, and the optical fiber has a core and a shell, and
the core and the cladding provide a fiber with an attenuation factor of less than 0,323 dB/km at a wavelength of 1310 nm, an attenuation factor of less than 0,310 dB/km at a wavelength of 1383 nm attenuation constant of less is 0.260 dB/km at a wavelength of 1410 nm, and the attenuation factor less 0,184 dB/km at a wavelength of 1550 nm.



 

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20 cl, 1 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to collimators which can be used to illuminate liquid crystal screens. The collimator is in the form of a wedge-like optical waveguide having a first end and a second end opposite to the first end. The first end is thinner than the second end. The collimator also has a visible surface passing at least in part between the first end and the second end, and a back surface opposite the visible surface. The visible surface has a first critical angle, and the back surface is configured to be reflective below the first critical angle. Furthermore, an end reflector, having a polyhedral (faceted) lens, is placed at the second end of the optical waveguide.

EFFECT: reduced overall dimensions of the collimator.

15 cl, 10 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to the field of laser technologies, in particular to devices for laser radiation transmission. The device contains a hollow light waveguide, the core of which is filled with water or water solution with an index of refraction, large index of refraction of the shell. On the ends of the light waveguide the transparent windows are located, and the internal surface of the shell of the light waveguide has the coating containing carbon nanotubes.

EFFECT: ensuring of transmission of powerful laser radiation.

7 cl, 3 dwg

FIELD: physics.

SUBSTANCE: protected document contains an opaque substrate, optical wave guide located on the substrate and/or in it and a coupler for light conducting into or out of the wave guide. Meanwhile the coupler has a hole passing through a wave guide and through the whole opaque substrate.

EFFECT: enhanced protection against document forgery.

15 cl, 9 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to the field of fibre optics and can be used in fibre communication lines, and also for creation of physical sensors. The device contains a light waveguide core from quartz or from quartz doped with nitrogen, reflecting shell from quartz doped with fluorine, round weighting rods from quartz doped with boron, in the shell from pure quartz or from quartz doped with fluorine, and protective and strengthening polymeric coat. The weighting rods are located at the distance from the centre of the light waveguide core to the shell of weighting rods, equal or greater than diameter of the light waveguide core.

EFFECT: improvement of radiation stability of the light waveguide and avoidance of diffusion of impurities forming radiative centres of colouring from weighting rods into the protective shell.

1 dwg

FIELD: radiation monitoring.

SUBSTANCE: detector has X-ray registration unit made in form of set of fiber-optic scintillators and fiber-optics communication transmitting unit (both made in form of single fiber-optic module, photoreceiver provided with signals electronic processing unit made in form of pixels optical system. Integral fiber-optic module is made in form of one-piece fibers on the base of argentums halogenides AgCl-AgBr-AgI. Registering part has active admixture and transmitting part has no active admixtures.

EFFECT: improved efficiency of registration.

1 dwg

FIELD: fiber-optic technology; laser processing of materials.

SUBSTANCE: optical fiber is substituted with target when adjusting. Target is positioned at plane of entrance edge of optical fiber. Mark is applied onto surface of target by means of single laser pulse passed through focusing unit. Observing unit is installed. Plane of target is observed through eye-piece and focusing unit. Center of mark at target is put in coincidence with center -f cross-point of eye-piece due to tilting of observing unit by means of adjusting aid. Target is removed and fiber optic is placed instead of it. Focusing unit is tightly connected with optical fiber.

EFFECT: simplified design; improved reliability, improved precision; widened range of laser radiation wavelength into optical fiber.

2 cl, 1 dwg

FIELD: shaping and processing radio signals.

SUBSTANCE: in order to enhance identity of copy generation while retaining ability of controlling input radio signal replication process, proposed device is provided with newly introduced (N -1) fiber-optic four-terminal networks, each of them incorporating Y-type internal adding and separating fiber-optic directional couplers.

EFFECT: reduced consumption of optical fiber.

1 cl, 27 dwg

FIELD: preparation of the optical fiber transducer as a sensitive element with preset characteristics, assembly of the transducer components, connection of the optical fiber ends respectively to a light source and to a photodetector.

SUBSTANCE: for bending the fiber to a preset angle and fastening of it on the first dielectric base of an optically transparent material the optical fiber is first laid on a flexible transparent dielectric base in the form of an arbitrary line with observance of the preset radius of curvature over the entire surface of the transducer base with the use of a stencil. Then the fiber is fixed on this base with the aid of polymer adhesive. The second dielectric base in the form of a polymeric laminated film is laid over the fixed fiber, after that the obtained assembly is connected in the conditions of thermocompression welding.

EFFECT: provided use of the transducer for reliable and precise registration of the fact and point of built-fragment injury of the object surface under control.

1 dwg, 1 tbl

FIELD: optical engineering.

SUBSTANCE: single-mode optical fiber has light-conducting part (4) of core, internal part (3) of envelope which surrounds part 4 of core and area of coating which surrounds the internal part (3) of envelope. Refractivity factor of core part 4 excesses refractivity factors of area 1 and 3 of envelope which are almost equal. Internal part (3) of envelope is made of SiO2 which includes doping fluoride in amount of 0,1-8,5 mass percent which results to compressing axial force of part 4 of core along its whole cross-section. Internal part 3 of envelope is additionally provided with doping additives to increase refraction and to get refractivity factor being practically equal to refractivity factor of area 1 of coating. Tube base is made of silicon dioxide and the base functions as area of coating. Internal part of envelope and area of core are formed by means of one or several reaction-capable gases. After they are formed the tube of base is subject to shrinkage and elongation to single-mode optical fiber. Single-mode optical fiber produced has low hydrogen-induced attenuation at 1500 nm wavelength.

EFFECT: lower hydrogen-induced attenuation.

15 cl, 8 dwg

FIELD: manufacture of optical materials and polymer compounds.

SUBSTANCE: proposed fluorated diene CF2=CF(CF2)nC(CF3)ROCF=CF2, where R is atom or fluorine or trifluoromethyl group and "n" is integer from 1 to 3 is produced by dehalogenation of various compounds. Specification gives description of polymer whose monomer is fluorated diene referred to above. Proposed optical transmitting device contained above-mentioned polymer and optical plastic fiber also containing above-mentioned polymer.

EFFECT: production of polymer suitable for optics and possessing high glass transition temperature.

10 cl, 21 ex

FIELD: optical engineering.

SUBSTANCE: dispersion-compensated fiber when being reeled upon small spool does not result to losses and it has stable temperature characteristic. For fibers with compensation of dispersion within wave range of 1,53 50 1,63 micrometers, bend losses with diameter of reeling of 20 mm are equal to 5dB/m and less. Chromatic dispersion equals to -120 ps/nmxkm, cut-off wavelength does not exceed 1,53 micrometers. External diameter of envelope equals to 80-100 micrometers, external diameter of coating equals to 160-200 micrometers. Adhesion property of surface of coating gum does not exceed 10gs/mm. Volumetric relation is reduced at least twice comparing to traditional module of dispersion-compensated fiber.

EFFECT: stable temperature characteristics; low losses; low dispersion of polarized mode in dispersion-compensated fiber.

29 cl, 13 dwg

FIELD: measuring technique.

SUBSTANCE: fiber-optic converter of movements comprises axially aligned nontransparent shield with opening and cords of input and output optical fibers. The distance between the input optical fibers and shield and the distance between the input and output optical fibers are determined from the equations presented. The receiving face of the cord of output fibers receives the section of fiber that is coaxial to the input optical fiber and opening in the shield. The receiving faces of the output optical fibers are arranged around the fiber section.

EFFECT: enhanced accuracy of measurements and simplified structure.

3 dwg

FIELD: laser engineering and fiber optics.

SUBSTANCE: proposed fiber optic conductor designed for intensifying radiation at wavelength ranging between 1000 and 1700 nm has oxide glass core and oxide glass shell. Core incorporates bismuth oxide as well as elements of group including silicon, germanium, phosphor, aluminum, and gallium. Fiber optic conductor affords luminescence in range of 1000 to 1700 nm when excited by beams with wavelengths ranging between 750 and 1200 nm, luminescence bandwidth being at half of height over 120 nm. Proposed method for manufacturing fiber optic conductor includes production of optical conductor blank and core. Oxygen and pair of chlorides of elements chosen from above-mentioned group are passed through quartz glass tube. The latter is compressed to produce blank in the form of solid bar. Pairs of bismuth chlorides are also passed through tube together with chlorides. Proposed fiber laser has fiber optic conductor, pumping source, device for beam entry in fiber optic conductor, resonator, and device for removing generated beam from resonator.

EFFECT: enhanced intensifying bandwidth and its efficiency, reduced concentration of unwanted impurities ensured by proposed method, enlarged laser tuning wavelength range.

20 cl, 6 dwg

FIELD: method for processing optical fiber.

SUBSTANCE: method includes placement of optical fiber inside processing chamber; injection of deuterium-containing gas into processing chamber; and at stage of deuterium processing - subjection of optical fiber to effect of deuterium-containing gas environment. At the stage of deuterium processing, concentration D of deuterium in processing chamber is computed during deuterium processing on basis of original value A of deuterium concentration in deuterium-containing gas inside the processing chamber, concentration B of oxygen in environment of processing chamber and concentration C of oxygen in deuterium-containing gas inside the processing chamber. Deuterium concentration in the processing chamber is regulated on basis of computed deuterium concentration D. in accordance to the invention, other gases may be used, such as hydrogen-containing gas and nitrogen-containing gas.

EFFECT: precise adjustment of deuterium concentration even in case when the gas, serving as carrier of deuterium-containing gas, is other that air, and percentage composition of the gas, serving as carrier, fluctuates.

3 cl

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